FEA Basics How Does FEA Work?

FEA is the application of the finite element method (FEM) to practical problems. The finite element method is a mathematical procedure used to calculate approximate solutions to differential equations. The goal of this procedure is to transform the differential equations into a set of linear equations, which can then be solved by the computer in a routine manner.

Differential equations are very important and present in many engineering problems because they represent the language in which physical laws are expressed. They connect changes in the internal variables of an object, such as displacement, temperature, or pressure, and their relation with the object’s geometry, physical properties, and external influences acting on it.

The detailed explanation of how this transformation from a physical law into a set of linear equations is performed is beyond the scope of this article, but here is a general overview of the process:

1. The physical problem is well defined, with set physical laws to be applied, in the form of differential equations.
2. The geometry of the object to be analyzed is defined, with the space occupied by it called the ‘domain’ and the surface enclosing it called the ‘boundary’.
3. External influences, acting on the boundary or domain, are also well defined, such as forces, pressures, temperatures, or heat sources. These are known as ‘boundary conditions’.
4. The ‘initial conditions’ of the object are also well-defined. These are the set of values of all internal variables at the first moment of the problem, for example, initial velocities, pre-stresses, or the initial temperature distribution.
5. The domain is then split into small basic shapes, known as ‘elements’. The set of all elements is known as the ‘mesh’. Also, the points where neighbor elements meet are called ‘nodes’. The size of the elements will determine the precision of the approximate solution, the smaller being the better. However, a higher number of elements used will increase the demand for computational resources such as memory and processor time.
6. Then, all equations and boundary conditions are ‘projected’ into the nodes, resulting in a finite—but often large—number of linear equations.
7. The linear equations are solved by the computer and the list of resulting variables for each node and elements are written to files.
8. The resulting data is used to make numerical analysis, visualizations and design decisions.

FEA Applications What Are Some Use Cases for FEA

Although the finite element method is not bounded to a particular type of physical problem, its main field of application is the structural analysis of solids. Structural analysis might include different types of loading and scenarios, but its main purpose is one: to predict if a given part or structure will withstand forces acting on it, safely.

This is achieved—according to the theory of the resistance of materials—by looking at the state of the part in terms of stress and strain. The maximum values obtained by any method (for example, FEM) are compared to allowable values to see if they conform to the safety range. These allowable values are most of the time specified by a design code such as ASCE, ASME, Eurocode, etc.

Some typical use cases of FEA software include:

• Steel or reinforced concrete structures, for buildings and other civil applications, load lifting, etc.
• Industrial equipment, such as pressure vessels, piping, boilers, rotating equipment, etc.
• Manufacturing equipment, such as mills, molds, tooling, etc.
• Automotive, aircraft or other transport structures, particularly for virtual crash tests.

FEA Concepts Introduction to Stress and Strain

Two very important concepts to grasp in order to start using FEA for structural assessment is stress and strain, as they are both related to the deformation of solid bodies. These topics are typically covered in depth when learning about the strength of materials, but here we will give a brief introduction.

When a solid body is subject to the action of external forces, such as pressure, contact or gravity, the body will undergo some deformation. The shape and magnitude of such a deformation depend on many factors such as the direction and magnitude of the external actions, the geometry of the body, and the rigidity of the constitutive material.

The simplest example of this is the deformation of a spring: when the spring is hung in a vertical position, it is in equilibrium with some characteristic length. If weight is attached to the lower end, the spring will extend, up until reaching another equilibrium point, this time with a longer length.

If the magnitude of the weight is varied, we will notice that the elongation of the spring is proportional to the weight, also known as Hooke’s law, and the constant of proportionality is known as the spring’s ‘rigidity’.

What is Stress?

What happens internally, is that the external forces are balanced by forces developed inside the material, which tends to oppose the elongation effect, causing the equilibrium state. These internal forces are known as the material’s ‘stress’, and are the result of cohesive forces at molecular levels. The higher the activity of the external force, the higher the stress developed by the material will be. Failure theories are based on limit stresses, that is, failure of the element is expected to occur when stress levels surpass a given threshold.

What is Strain?

When trying to write Hooke’s law in terms of material stress, it was noticed that elongation of elements was not a consistent measure. If the geometry of a test specimen (e.g., for a uniaxial test) was changed, then the rigidity constant didn’t generalize for a given material. What was noticed is that a special measure of deformation should be considered. This is known as the material ‘strain’ and has a few different definitions, such as ‘engineering stress’ or ‘true stress’. These definitions allowed to state a relation between the material’s stress and strain, using a measurement of the material rigidity known as Young’s modulus.

It is also important to note that even stress and deformation being the main goal calculation with FEA, they are not the only important prediction that can be made with it. Other very useful information for a given structural system that can be obtained with FEA include:

• Natural vibration frequencies and modes
• Forced vibration (harmonic) response
• Buckling limits and modes for thin structures
• Fracture propagation modes and fatigue life

Industrial FEA Key Industries Using FEA

Automotive

In the automotive industry, FEA software simulations are performed to assess the structural safety of designed components, such as chassis, anchors, suspension, bodyworks, etc. One of the most interesting applications is virtual crash tests, where a dynamical simulation is performed to predict deformations and energy absorption against crash impact. Here is a link to a project simulating a car suspension’s deformation and stress.

Industrial Equipment

For industrial equipment design and engineering, finite element analysis software is widely used. In the processing industry, for example, pressure and heat loads are applied to predict stress levels in piping, pressure vessels, tanks, and similar equipment. Another possible use for the industry is the simulation of forging processes for mills, benders, and stampers, to measure stress levels and spring-back magnitude of forged parts. 

Civil Engineering and Structural Design

For civil engineering and structural design, FEA software has unleashed the power of fast and accurate analysis, with the possibility of automatically applying code load combos and checking compliance. Typical analysis scenarios include static loading, equivalent static loading, dynamic performance in seismic scenarios, natural vibration modes, and frequencies calculation. Here is an example project performing structural analysis on a steel structure:

Applying FEA Why is FEA Important?

FEA is the defacto technology for detailed stress analysis and deformation prediction across almost every engineering field. As more analysis tools become accessible to designers and engineers, it has a lot of space to grow its presence. As we have been able to see, it is very versatile and powerful, making it a must-have tool in any product design portfolio.

The most recent trend in FEA software is cloud-hosted simulation services and tools. Companies such as SimScale provide simulation tools that run in the web browser and make use of remote servers for the computing tasks, freeing local resources, and lowering the requirement for powerful hardware and special software installations.

FEA For Beginners How to Learn FEA (With SimScale)

If you are interested in FEA software and want to start leveraging its benefits in your projects, you can make use of the following resources:

• Sign up for a free SimScale account, where you can set up your simulations in just a few minutes.
• Read more about FEA on the web, for example, FEA for All,  Stress eBook, or SimScale.
• Read the SimScale FEA Documentation

The post FEA For Beginners appeared first on SimScale.

CFD is the acronym for ‘computational fluid dynamics‘ and, as the name suggests, is the branch of fluid mechanics that makes use of computers to analyze the behavior of fluids and physical systems. CFD modeling and analysis became a popular online simulation solution as the difficulty grew in applying the laws of physics directly to real-life scenarios in order to make analytical predictions. This fact became especially prevalent for fluid flow and heat transfer engineering problems.

CFD Analysis Basics Introduction to Fluid Mechanics and Heat Transfer

Fluid mechanics is the science that studies the physical behavior of fluids: liquids, gases, and plasmas. As such, it relates the forces acting on a fluid body and the consequent changes in internal fields such as velocities, pressure, density, and temperature. These relations are mathematically stated through differential equations, the Navier-Stokes equations being the corollary of the known laws for the behavior of viscous fluids. Here are the Navier-Stokes equations in simplified vector form:

$$ \frac{\partial \rho}{\partial t} + \nabla \cdot (\rho\textbf{u}) = 0 $$

$$ \frac{\partial \rho\textbf{u}}{\partial t} + \textbf{u} \cdot \nabla (\rho\textbf{u}) = \nabla \cdot \sigma + \rho\textbf{f} $$

$$ \frac{\partial E_t}{\partial t} + \nabla \cdot (E_t \textbf{u}) = \nabla \cdot \sigma\textbf{u} – \nabla \cdot \textbf{q} $$

On the other hand, heat transfer is the study of how thermal energy gets generated, stored, transported, and transformed. The main mechanisms it analyzes are:

• Thermal Conduction: (Diffusion) The spread of heat across materials, such as solids or fluids, from regions of high temperature to regions of lower temperatures.
• Thermal Convection: The transport of heat with the flow of a fluid. Fluid flow can be driven by external work (forced convection) or by buoyancy, which is the movement of fluid with varying density in the presence of gravity (natural convection).
• Thermal Radiation: The generation and absorption of heat through electromagnetic waves.
• Phase Changes: The release or absorption of heat through transitions such as boiling, melting, condensation, etc.

Laws of physics for fluid flow and heat transfer are expressed in terms of differential equations, most of the time with many related variables. It happens to be that some of the equations for both fields are similar; for example, the diffusion of a scalar through a flow field and the diffusion of temperature.

The most general of these laws for the flow of fluids is the set of Navier-Stokes equations. Yet, due to their complexity, solving these equations for exact solutions can only be achieved in the simplest of cases.

How Does Computational Fluid Dynamics Work?

This is where numerical analysis and computers come into play; online simulation. By using numerical approximations, CFD turns the full differential equations into systems of linear equations, which are then solved to obtain field values such as velocities, pressures, and temperatures on a finite (but often large) number of points in the domain of the problem.

Although numerical methods for obtaining approximate solutions to differential equations have existed for many centuries, the ability of computers to store large amounts of numerical data and perform fast operations on them is what has turned technology into the most practical tool for physicists and engineers. At the same time, this means that one often finds that the application of CFD to practical problems is limited by the computational power available.

CFD analysis allows for the modeling of fluid because of its versatility in numerically solving equations of state and physical behavior, expressed in differential or explicit form. Also, CFD modeling analyses as heat transfer problems are of paramount practical relevance, any competent simulation tool includes modules to calculate temperature distributions alongside pressure and velocities. Also, some applications can also include analysis of solids for elastic deformation or chemical reactions, among other non-fluid applications.

Some typical use cases for CFD modeling and CFD online simulation include:

• Flow through piping and accessories such as valves, tees, and reductions, in order to predict pressure drops, velocities, and vortex formations.
• Vehicle aerodynamics, including automotive and aircraft, in order to predict drag, lift, and downforce.
• Wind engineering for buildings and wind analysis, to predict wind forces, vortex formation, and pedestrian comfort.
• HVAC systems, to assess the performance of ducts or optimize thermal comfort for artificial or natural ventilation and for energy consumption.
• Heat exchangers, to predict heat transfer and pressure drops.
• Electronics cooling, to predict natural and forced cooling strategies performance.
• Windmills, to predict blade lift, velocity, and power generation at given wind speeds.
• Pollution dispersion and airborne contamination control, cleanroom design.
• Ship and offshore structures for hydrodynamic performance.

In order to begin understanding how CFD modeling and analysis works, here is a list of typical characteristics of a CFD problem:

• The problem is defined over a closed geometry, referred to as the ‘domain’ enclosed by its ‘boundary’.
• The phenomena to be simulated are well defined, such as the presence of heat transfer, turbulent flow, chemical reactions, multiple phases, multiple bodies, etc., with known material properties and coefficients for state equations.
• Initial values, as well as values on the boundaries for the considered fields, are known. This might include pressures, flow velocities, walls, temperatures, heat sources, etc.
• The geometry of the domain is split into small basic shapes known as ‘cells’. The set of all cells is known as the ‘mesh’. The size of cells will determine the precision of the solution (the smaller, the better), but the number used will define the demand for computer memory (the smaller cells, the higher the count, the more memory will be consumed, and the longer time the solution process will take).

What Commercial CFD Software Is Available?

There are many CFD software offerings in the market, some of them of general-purpose with many capabilities and some tailored for specific applications. Companies even develop their own in-house codes for specific engineering tasks. Here is a list of the most used, general-purpose suites in the industry:

• ANSYS Fluent and CFX
• STAR-CCM
• COMSOL
• OpenFOAM (Free, Open-Source)
• CAD-integrated tools in SolidWorks/Autodesk (basic functionalities)

A very good alternative to traditional, desktop workstation-based suites is the online simulation platform SimScale. It is built upon established solvers, including OpenFOAM, providing an easy workflow and a modern user interface accessible through any web browser with computations run on remote cloud servers, which helps relieve your local machines from intensive and lengthy tasks.

Explore CFD in SimScale

Discover More

Key Industries Using CFD Analysis

Here are some of the most representative industrial sectors leveraging the power of CFD analysis, and a short description of why they do it:

Automotive

The automotive industry makes use of CFD for many applications, with the most important being vehicle aerodynamics. CFD analysis is used to predict drag, downforce, and stability against cornering/crosswind flow. Other automotive applications include engine combustion and thermal performance, ventilation, exhaust fumes, and more. Here is a link to an example project simulating the aerodynamics of an F1 car.

Aviation

In the aviation industry, the main application of CFD is also aerodynamics, with the aim of optimizing the lift/drag ratio and studying instabilities. Here is an example project on airplane aerodynamics, that touches on how simulation can give valuable insights into airflow and aircraft performance. Other important fields for online simulation within the aviation industry include ventilation and air filtration.

Manufacturing

In the manufacturing industry, CFD is used to study the performance of the cooling system in consumer products, especially those making use of electronics. Here is an example project—enclosure design for a Raspberry Pi.

Learn Computational Fluid Dynamics Why Is It Important?

As product development cycles are getting shorter in time, and as more and more products rely on precise performance to achieve success, numerical online simulation is always gaining more relevance. Its ability to make precise performance predictions with fast, reliable, and easy workflows unleashes the possibility of carrying optimization right from the engineer’s workstation, even before the first prototypes are built.

CFD simulation is not the exception to this trend, and with online simulation offerings such as SimScale, which brings lots of computational power and optimal workflow at affordable prices, without the hassle of complex CFD software and hardware installations, these advantages are reachable to a larger number of companies, even those on tight budgets.

CFD and SimScale How to Learn CFD Analysis with SimScale

If you wish to learn more about CFD modeling, CFD online simulation, and CFD and start leveraging its advantages for your projects, I recommend you to:

• Sign up for a free SimScale account, where you can start simulating right away. Check, for example, the repository of public CFD projects for airflow simulation and more.
• While you’re at it, check out the SimScale blog for all things CFD.
• Read the SimWiki page on everything related to Computational Fluid Dynamics (CFD).

Set up your own cloud-native simulation via the web in minutes by creating an account on the SimScale platform. No installation, special hardware, or credit card is required.

Start Simulating Request Demo

The post CFD Modeling, Analysis, and Online Simulation For Beginners appeared first on SimScale.

Windy Cities What Is Pedestrian Wind Comfort?

If you are a sharp-eyed person, you might have noticed that in some specific locations, there is a greater tendency for strong gusts to develop. So, there must be some correlation between the wind and the surrounding buildings causing the gusts. In the world of engineering, this is referred to as pedestrian wind comfort. Pedestrian wind comfort is the branch of wind engineering dedicated to studying wind effects, what causes them, how they develop, and how the urban environment can be designed to control them.

Wind Assessment Why Is Assessing Pedestrian Wind Comfort Important For Urban Planning?

Any building construction, be it a high- or low-rise building, bridge or tunnel, will have an impact on its surrounding environment. Wind flow disruption is one of the many possible impacts. Especially in urban areas, wind effects such as tunnel throttling or vorticity can be created. If not planned beforehand, these effects can even be harmful or dangerous to people using or even nearby the affected facilities.

This paper addresses the topic of pedestrian wind comfort, from origin and
definition to wind comfort analysis, criteria, and example case studies; all meant to
form an in-depth understanding of the field.

Download Whitepaper

By assessing pedestrian wind comfort, urban master planners can predict the behavior of wind flow around proposed buildings while they are in the design phase. Wind speeds and other parameters can be calculated at pedestrian levels, and a comfort assessment can be made using specific criteria such as the one shown in the following graphic. This allows for improvements to be directly implemented into the design and assessed in cycles until a satisfactory construction plan is achieved.

Download our ‘ Tips for Architecture, Engineering & Construction (AEC)’ white paper to learn how to optimize your designs!

Download Now

Pedestrian Wind Comfort How Do You Assess Wind Comfort In 2019? 

Typically, the assessment starts with local weather data showing what is known as a wind rosette. A wind rosette (or wind rose) is a graphic tool used by meteorologists to give a concise view of how wind speed and direction are typically distributed at a particular location.

This chart presents the maximum (or typical) wind speed value for various directions of wind flow. This information, alongside the master plan model, is used to predict the local wind effects, such as vortex creation or tunneling. The results obtained are then used to assess the pedestrian comfort for all regions of the model.

There are three fundamental methods used to carry out the assessment of wind behavior for master planning:

1) Full-scale testing
2) Wind tunnel testing
3) CFD simulation

Over the last decade, the CFD (computer fluid dynamics) approach has increasingly become the tool of choice due to its ability to carry out pedestrian wind assessment using a faster and easier workflow. Software providers such as SimScale have come out with many specialized tools that make this possible.

One of the biggest benefits of using CFD simulation in the design phase of a building project is cost reduction. The following picture illustrates the impact on project cost caused by changes in different design phases. In the conceptual phase, early information is available such as rough models for terrain and present buildings. Simulation is used to run fast iterations with low detail levels, and these inform the design process. In the second case, detail engineering is being supported by simulation. The wind behavior is analyzed in detail and with high accuracy, having the aim of assessing regulation compliance.

However, CFD simulation can be resource demanding. A company aiming to leverage its benefits needs a dedicated, specialist engineer, working alongside the software. Traditional CFD software tools demand high-performance computers (HPC), and their added overhead: specialized software and configuration, maintenance, energy costs, and know-how barriers.

This is where SimScale enters to offer an alternative; a cloud-based platform, with zero hardware and software footprint, and access to unlimited computing power. In this article, we will explore a case study using CFD analysis with the SimScale platform.

Learn how to leverage the cloud-based SimScale platform to optimize your design based on accurate results and ensure pedestrian wind comfort and safety by using a standard web browser!

Watch Webinar

Designing for Wind Case Study: Flow Simulation Around a City District

In the following case study, we will evaluate the wind flow around two city districts, where the construction of buildings is being proposed. The two scenarios are then assessed using CFD simulation in different design phases.

Scenario 1: Early Master Plan Design

In the first scenario, the construction of three buildings is being investigated. The focus will be on wind behavior in the recreation areas that are looking to be developed. Models of the surrounding buildings and the proposed buildings are reviewed, with low detail level. This scenario only evaluates the main wind direction, and is analyzed for one velocity value.

The case is simulated using a virtual wind tunnel model with the recently released Lattice Boltzmann (LBM) solver on the SimScale platform. The model is run with coarse resolution mode to get fast results. The applied method avoids the need for a meshing step or CAD clean-up. The wind velocity at two meters height is obtained and plotted:

We can see the Venturi effect on the interest regions, with significant wind accelerations within the immediate vicinity. This will constitute an uncomfortable condition for pedestrians. A design variation that includes adding vegetation to improve the condition is then proposed and tested:

The new design layout is simulated, and the results show an improvement in the condition with room for further progress:

Sign up and check out our SimScale blog for much more!

Sign Up Now

Scenario 2: Detailed Validation

For a second detailed engineering validation scenario, a model of New York’s Central Park Tower is considered. As can be seen from the CAD model picture, more detail is included such as the surrounding buildings, terrain, vegetation, and building facades.

The simulation is set up with a finer resolution in order to capture the details of the model and smaller flow artifacts. Specifically, different levels of refinement are present in the simulation: high refinement for the tower, medium refinement for its vicinity, and low refinement for far-field positions. The input wind profile is modeled following a logarithmic law.

Many wind directions and velocity magnitudes should be considered in order to assess comfort using a methodology such as Lawson’s or NEN-8100. For the prevailing wind direction, the following results were obtained:

Wind Comfort Conclusion

The webinar presented two different cases using CFD simulation in AEC applications assessing pedestrian wind comfort. The first case showed a conceptual design phase analysis, with low detail levels but fast turnaround times. The second case showed a detailed design validation, with a more involved analysis, but with fine-grain detail in the results, which can be used with confidence for code compliance assessment. By leveraging the solver based on the LBM method available with SimScale, the simulations were easily set up, ran in the cloud on multiple GPUs, had zero local hardware and software overhead, and allowed for fast access to results.

Watch our recent webinar recording by filling out a short form here and check out our published slide deck for more information. 

The post How to Assess Pedestrian Wind Comfort in 2019 appeared first on SimScale.

Open Source Software The CAE Landscape

The fact is, open source anything has always been a concern for engineers and managers alike. Historically, it has a reputation for being less secure and structured while being free for anyone to use. Yet, amidst the established landscape of CAE (computer-aided engineering) software, where best practice dictates, a private software company is responsible for planning, developing, testing, releasing, selling and supporting the tools used for modeling and calculation, open source software and tools are still used by many.

And, as many of these tools are used for the design of safety-critical systems (airplanes, power plants, life support devices, etc.), this puts a large amount of responsibility on those companies, as well as a significant amount of trust being placed in them by their users.

However, the question still arises: is such a heavy dependency on just a few companies necessarily a bad thing? Taking a look at the current state of CAE tools, we can see that succeeding companies have lived up to the expectations placed upon them with minimal mishaps.

Nowadays, their products are considered the norm by which simulations are measured (with big names such as Ansys, Abaqus, Fluent, NX, Comsol, Matlab, and the like leading the way), and have made an immeasurable contribution to the advancement to the field.

In this article, we will discuss an alternative approach to the established model of CAE tools, which is open source software. These are the kinds of tools at the heart of SimScale. We will explore what they are, the reasoning behind them, and the benefits they bring to the interests of the user.

Open Source Software Overview of Open Source Software

Software is no more than a set of instructions given to a digital computer to perform a particular task. In our CAE case, those tasks involve applying numerical models, solving equations, and crunching huge amounts of numbers to give them a useful meaning or for plotting them onto the screen. The form that these instructions take is referred to as the “source code”.

The “source code” used to build a commercial software tool is a trade secret, governed by copyright and other special laws. This is to protect the investment and the developer’s ability to compete in the market. Due to this, the code is hidden from the user and any attempt to modify it or make it public is illegal. This guarantees that the tool you use behaves as it is intended by the developer, while disallowing users from auditing it, so that users must trust the provider.

Open source software is a model in which the source code is not hidden, but is instead made freely visible to the user. You can easily monitor and check what it is doing and how it is doing it. Notice that this doesn’t mean you can copy or modify the code—only “see” it. And (although common), not all open source software is free to use without paying license fees.

Moreover, there is a whole range of “openness” in which a software program can be categorized: from “closed source”, “passing through”, “can be seen”, “can be modified”, up to “can be copied”. On the commercial side, there is “cannot be redistributed”, “can be redistributed”, “can be modified and licensed”, and others.

But what is the motivation behind this? There are two main reasons why a software source code can be “opened”: first, to allow public development, and second, for transparency. In the former case, this model has unlocked the advent of tools that are developed by a collaboration of people who are united in the sole purpose of building what they need. In the latter case, companies try to build trust in their product.

As you can imagine, what adds to the complexity of this field is that every piece of software and every company or team behind them are different. Sometimes teams work for no profit, and sometimes companies open their sources but then need to monetize their product to remain viable. It is not rare to find software that is free to use without paying license fees, with the sources opened, but where premium technical support service is offered at a price. In fact, this is the most common case in OSS CAE tools, as we will discuss in our examples.

Download this free case study to learn how the SimScale cloud-based CFD platform was used to investigate a ducting system and optimize its performance.

Download Case Study

CAE Open Source for Engineering

Software tools are of paramount importance in the modern age of engineering practice. Data analysis, numerical simulation, and data visualization are some examples of what we can currently do with them, and the benefits they bring to our projects are countless. Given its popularity and success, it is no surprise that some of those tools embrace the philosophy of open source software to achieve user loyalty and growth.

So what are the benefits of opening the source code of CAE tools? The first is transparency; you can check that the tool you are using is implementing the equations and algorithms as intended—not taking shortcuts or creating errors. Software tests and validation cases are made public, reported in the literature and online, and can be duplicated at users’ convenience. If you find an error, you can report it to the developers and follow its fixing process—you can even try to fix it yourself.

The second key benefit is the ability to modify or make derived work. Want to make a change to the computing algorithm? Go ahead. Want to implement a slightly different set of equations or a completely new set of your own? You can do it. Want to implement a whole new feature or an entirely new tool without the need to start from scratch? You get the idea. There are no restrictions and endless possibilities.

CAE Solvers Open Source CAE Solvers in SimScale

SimScale uses a mix of open source software to make its integrated web platform work; the majority of which cannot be seen by users. However, in this article, we will focus on the core of the functionality: the numerical simulation and data visualization tools. These are well-recognized projects with widespread usage and adoption in many engineering fields and companies, as well as in universities and research laboratories. They also have interest communities, with Internet forums and even mailing lists.

Code_Aster

Developed as an in-house tool in the 1980s by the French government energy department (EDF), Code_Aster’s chief purpose was to fulfill bureaucratic simulation needs. This included simulating thermal, structural and coupled phenomena in the design of components for power generation facilities, including nuclear facilities. It is based on the finite element method (FEM) and includes many pre- and post-processing tools to cover a very wide variety of possible applications.

The open source version was first released in 2001. Since then, it has been updated and maintained by the same development team. The release includes the solver, auxiliary tools to set up and run simulations, and over 2000 test cases. The official documentation with theoretical development, application, usage, and validation cases is also available on their website.

OpenFOAM

Started development in the 1980s at Imperial College, London, with the aim of providing a base frame to develop simulation tools for continuum mechanics problems modeled with partial differential equations. These include, but are not restricted to, computational fluid dynamics (CFD). The authors later founded a company to manage the development and release of the software. To date, the rights to the software belong to a non-profit organization called the OpenFOAM foundation, and development is done by a company called CFD Direct, which also offers professional services for training, technical support and custom development of tools.

The official suite of tools includes solvers for many types of fluid flow problems, solid mechanics, conjugate heat transfer, electromagnetism, molecular dynamics and more, as well as meshing and other pre-processing and post-processing tasks.

ParaView

The development started in the year 2000 in a joint effort between Kitware Inc. and Los Alamos National Laboratory. It was funded by the US government with the aim of fulfilling the needs of data analysis and visualization, particularly for very large sets.

A very characteristic feature of this software is the capability of server-side processing of the data and client-side visualization, both of which allow the optimal exploitation of computational resources. This is implemented by the SimScale platform, where all the processing is done in the cloud and the visualization is carried out directly in the web browser.

Conclusion

In this article, we have reviewed the nature of open source software, what the motivations behind it are, as well as some of the benefits and disadvantages. In particular, we have reviewed the main open source CAE tools used by the SimScale platform.

To get started with the SimScale platform, you can watch this webinar recording:

We can see that these are very substantial projects that are often backed by private companies and government institutions, with thriving interest communities built around them. We have also learned that although you can use them without paying a license fee, there is often the opportunity to purchase additional support and technical services.

Ultimately, to build trust and learn to use the tool, you can always implement your own test cases suite and corroborate that the results are what you expect.

If you enjoyed this article, check out the SimScale blog for much more!

The post How Reliable is Open Source Software for CAE? appeared first on SimScale.

These requirements include aspects such as thermal comfort, control of the concentration of pollutants (i.e., bacteria and viruses), and room temperature regulation. Depending on the nature of the operating room environment, even extremely specific factors such as air velocity at the patient wound location needing to be below a threshold value of 0.2 m/s must be acknowledged.

All of these aspects are controlled by the ventilation strategy implemented in the given room. Therefore, for these requirements to be met efficiently, design engineers must count on analysis tools that provide the most reliable and detailed information as possible. In this blog post, we have provided a case study using computational fluid dynamics (CFD) to analyze and optimize the ventilation system of a hospital operating room.

Learn how to use fluid flow simulation to test and optimize the ventilation of hospitals and other healthcare environments.

Watch Free Webinar

Applications of CFD in Hospitals

The use of CFD in the planning of ventilation systems provides design engineers with many advantages. The use of simulation allows them to solve the flow problem with a computer, obtaining precise results, and model the case with varying grades of geometry simplification. This, in turn, optimizes computation time and resources, allowing engineers to calculate the temperature at every point in the geometry, as well as calculate the magnitude and direction of the velocities. This ability allows engineers to then predict the movement of bacteria and contaminants on a granular level via three-dimensional information.

Some of the common goals achieved by engineers with CFD analysis of airflow include:

• Optimizing air movements in closed spaces by eliminating air recirculation zones
• Saving energy through more efficient heating and/or cooling
• Reducing the spreading of bacteria by removing airborne bacteria through effective ventilation
• Improving thermal comfort levels for patients and medical staff
• Quickly regulating temperature without large overshoots.

The advantages and benefits of CFD have turned it into a very popular tool for closed space ventilation, such as hospitals rooms.

Case Study: Airflow in an Operating Room

The case study detailed below was kindly provided by Veryst Engineering and was presented by Alireza Kermani, Ph.D. P.E., Senior Engineer at Veryst Engineering, in this joint webinar.

Our case study model consists of a typical hospital operating room. This includes simplified geometries for patient and doctor, bed, wardrobe, hospital equipment, illumination, and ventilation:

In this case study, the floor, walls, and ceiling are considered to be heat insulated. The ventilation flow rate is based on an estimate of 6 ACH (air changes per hour) and the typical air inlet temperature. Thermal loads are used for bodies, equipment, and illumination:

The following image is a visualization of air flow results from the CFD simulation of the operating room:

CFD Simulation Findings

In our case study, it was found that a recirculation zone occurred behind the doctor. This outcome was not desired, as bacteria and other contaminants could get trapped in this area. The fluid flow simulation also found that there was a flow of air from the patient towards the doctor, which also needed to be reconfigured in the design. Another recirculation zone was discovered above the wardrobe, which again could have resulted in airborne bacteria concentration. The flow at the wound site of the patient was also examined in order to see that the velocity threshold value requirement was met.

Thermal Comfort in the Hospital Operating Room

In cases like these, thermal comfort is a relative criterion as it controls the satisfaction of occupants within the environment. This factor is not directly related to the equations of flow but instead assessed by subjective evaluation. One technique used by engineers is to correlate the results of registered psychological experiments as published in standards with thermal analysis variables, such as flow temperature, velocity, and humidity, which can be obtained from CFD analysis results.

The results for the test case showed that there is a probability of 56% that the patient is dissatisfied with the room temperature, with an overall sensation of being cold.

Airborne Transmission of Bacteria

In our case study, airborne transmission due to coughing was also analyzed. After coughing, the portion of large droplets fall on the floor, and the portion of smaller droplets become aerosolized and start to move with the airflow. The change of airflow due to coughing is modeled using experimental data for cough flow rate vs. time. The following bacteria movement pattern was found:

It can be seen that most of the bacteria leave the room through the ventilation exhaust 30 seconds after coughing occurs. Yet, due to flow recirculations, some of the bacteria remains in the room, which is not desired. The following plot shows the percentage of bacteria that leaves the room at the ventilation outlet versus time, which correlates with the probability of infection:

We see that 90% of the bacteria leave the room at around the 30 seconds mark, but even after 360 seconds, the remaining 10% of the bacteria stays inside the room and is never picked up by the ventilation exhaust system. This poses a problem.

Design Optimization for the Operating Room Ventilation

The chief question that arises from this situation is: how can we use this information to improve the ventilation system so bacteria is removed faster and thermal comfort is improved? One possible method is to move the location of the ventilation exhaust, by leaving all other design variables untouched. After examining the flow pattern, three design alternatives were proposed:

All three design variations are modeled and simulated with CFD. Here is the comparison of the airflow pattern results among the design variations:

In design 1, a recirculation zone exists above the patient, but with low velocities in the plane. The next design (Design 2) there is only a minor recirculation next to the wardrobe. In the final design, (design 3) there is a recirculation zone behind the doctor, at a low level. We also compare the average temperature of the room for each design. We find that the energy efficiency can only be improved by relocating the ventilation outlet:

In order to compare airborne transmission of bacteria performance for the various ventilation strategies, this plot is used to show the bacteria leaving the room through the ventilation exhaust in time:

We see that design 1 removes all bacteria at around 15 seconds. This design corresponds with the air outlet located above the head of the patient. The other designs actually perform worse than the original configuration.

Conclusion

Through our case study, it was shown that the airflow of an operating room can be optimized with CFD simulation. CFD has many benefits including:

• Increasing comfort levels and improving ventilation design and energy efficiency of buildings
• Gaining better insight into aerosol contamination dispersion characteristics to optimize airflow pattern in hospitals, laboratories and cleanrooms.

A great way to begin leveraging CFD technology is with the SimScale platform, which can be accessed online, via a standard web browser. To discover how to start your own airflow simulation, check out our public projects. 

The post How To Use CFD To Simulate Airflow in an Operating Room appeared first on SimScale.

While advancements in information technology have opened a plethora of opportunities available to professionals, challenges to meet the demand for taller buildings, longer bridges, deeper tunnels, safer highways, and greener homes among other designs are becoming increasingly common for engineers.

Engineering skills are often classified into “hard” and “soft” categories, in an effort to distinguish between technical skills (e.g., structural design) and social skills (e.g., team leadership). Both are important in order to be successful, and both can equally benefit from the right kind of technical tools.

In the following, we will discuss a number of common areas where civil engineers can fall short, and the way they can leverage technology to avoid these pitfalls in order to get better results from their work. Here are five mistakes civil engineers should avoid:

Mistake 1: Failing to Effectively Communicate

Engineers are often marked as solo workers, lone wolves, or introverts. A stereotypical depiction is one that prefers smaller teams and working in isolated environments. Yet with the challenge of facing bigger more elaborate projects, there is a growing need for larger teams working collaboratively in order to complete work.

In turn, working in large teams creates a demand for effective communication tools. Traditional telecommunication tools from phones to emails often lack complete functionality, because they lack traceability and can be cumbersome and confusing. Can you remember the last time you dropped a call or lost an attachment? Other alternative channels must be in place for full accessibility between teams.

Collaboration tools include features such as chat, document sharing and hosting, task management, progress tracking, and traceability. These unified communication systems also boost security and protection for your business. Some popular services in this area to try are Microsoft Teams, Slack and Trello for team management and cloud apps such as Google Docs or Microsoft Office Online.

Mistake 2: Not Providing Quality Service as Civil Engineers

Today, the market is fully saturated with international projects and competition from all around the globe. A high quality of service represents a competitive advantage for civil engineers that can gain client fidelity and more. On the other hand, poor service is a mistake that can make the client search elsewhere for their next project.

Sometimes engineers fall in the trap of thinking that simply fulfilling requirements is enough to succeed. Complying with codes and providing a cost-effective solution is not enough for a project to succeed. Although these are important, client satisfaction is equally if not more important. Try to understand the client needs beyond technical requirements, or implement some of their ideas into the design. If you can make the client feel part of the project, and feel satisfied in all of their needs, that client will surely come back to you with more work.

Learn how to accurately predict wind loads on buildings without leaving the web browser. Watch the webinar below.

Watch Webinar Recording

Mistake 3: Ignoring the Big Picture

Another common mistake in engineering is failure to consider the full environment of the project at hand, or having a holistic view. The impact of construction on its surroundings must always be considered and is a key component to a project’s success. This can include considerations for aesthetics harmony, environmental impact as well as future development.

In this aspect, code compliance draws the bare minimum requirements engineers and architects have to achieve. Exceeding these primary codes will ensure the success of the construction for its complete lifespan. Foreseeing and then optimizing factors such as carbon footprint, energy consumption, wind disruption, green materials, durability as well as aesthetic impact beyond code requirements brings a competitive edge to civil engineering projects.

Mistake 4: Stopping at Structural Calculations

One of the big changes that computers have brought to civil engineering is structural calculations. Numerical load and resistance analytics have allowed structural engineers to be more confident than ever. Structural code compliance and dimensioning is now a fully automated task. In turn, this allows engineers to focus on optimizing the structure for factors such as cost, aesthetics and failure safety.
Yet, computer calculations don’t stop at code-compliant driven structural analysis. The whole field of computer-aided engineering (CAE) brings tools for every engineering calculation task.

Some examples for fluid flow simulation (CFD) include predicting wind loads on buildings, ensuring pedestrian comfort in urban areas, validating ventilation and air conditioning, controlling air quality and contamination in cleanrooms, laboratories or underground spaces, and optimizing thermal comfort in working and living environments. Finite element analysis can be used for detailed stress analysis, dynamic seismic performance assessment and non-linear materials.

See, for example, the following video by The B1M, featuring the cloud-based simulation platform SimScale:

Mistake 5: Not Cultivating Enough CAD Creativity

With 3D CAD tools, visualizing the end result of a project is no longer a task for one’s imagination. The ability to model almost anything—from furniture to facades and their respective surrounding elements alongside photo-realistic rendering of the models—unleashes the possibility of foreseeing the aesthetics and visual impacts of the project in a way never possible before. The majority of civil engineers predictably already make use of these CAD tools. However, they might not be leveraging the full power of available software, which is a mistake.

Three-dimensional CAD models can be leveraged for many uses that can empower greater engineering activities. One example of this is virtually testing and optimizing the CAD models using FEA and CFD simulations. With the emergence of cloud-based tools like SimScale for simulation and Onshape for CAD, computing power capacity is no longer a limiting factor.

Another example of leveraging CAD models is through using virtual reality. With VR headsets, a civil engineering project can be explored in an immersive manner. This technology can augment the realism of the model, and the capacity of the civil engineers and architects involved.

Conclusion

The ability to learn new techniques through innovative tools to adapt to the advancing technological world we live in is increasingly important. The evolution of our workplaces due to the cutting-edge information technology era is a reality. Therefore, learning and adapting is key to mitigate the risk of being left behind. 

If you enjoyed reading this article and the mistakes civil engineers should avoid, you might find this topic interesting: ASCE 7 | How to Comply with this Building Code and the Role of CFD.

The post 5 Mistakes Civil Engineers Should Avoid appeared first on SimScale.

While ASCE 7 covers loads from a variety of sources (including gravity and natural disasters), one of the primary concerns for building developers looking to meet this standard is wind loads. This is an especially important consideration for high-rise buildings or bridges, where wind loads can have a considerable influence on the design process.

Code Philosophy and Compliance

Engineering codes such as ASCE 7 arose from the need to prevent catastrophes related to buildings and other man-built systems. Their primary goal is to guarantee that a given construction or installation is safe and secure to be used for its intended purpose. Every common element that may pose a safety risk is generally covered by an engineering code, from electrical wiring to piping, boilers, pressure vessels, tanks, and entire structures.

While every code is different, they all follow the same philosophy: to provide minimum standards and proven practices to engineers at every stage of a project, from conception through to construction and operation, installing confidence that the final product is safe, reliable and efficient. They may include regulations, calculations, and quality control requirements. Some codes are required by law, while others are enforced by the project stakeholders.

Engineers must be familiar with the codes that cover their area of expertise, and any legal requirements related to code compliance. This is an integral part of the engineering profession, not only for design and audit engineers, but also for project managers, builders, fabricators, and operators.

ASCE 7 Wind Load Calculation and CFD

The calculation of wind load on a structure that follows the ASCE 7 code begins with the building being classified according to its:

1. Geographical location and surroundings (to determine wind gust speed and its modifications)
2. Importance factor (standards are higher for critical buildings such as hospitals)
3. Geometrical shape and characteristics (to determine the adequate pressure calculation method)

Once the standards have been determined, the code permits the application of one of three methods for the calculation of the wind pressure on a structure, depending on its geometrical characteristics.

Simplified Method

If your building is low rise, symmetrical, completely enclosed and rigid (lowest vibration frequency larger than 1 Hz), and there are no flow-disturbing elements nearby, the simplified method is permitted. The building should not be prone to developing unstable motions (such as galloping or fluttering) or be situated in a location where turbulence may occur (such as in the wake of another building or on a hill).

Analytical Method

Any building that falls outside of the characteristics above must use the analytical method. This applies to flexible buildings (vibration frequencies below 1 Hz) and takes into account effects caused by motion in the direction of the wind load. The building still has to be of a regular shape and not be prone to instability due to wind load or turbulent flow.

Wind Tunnel Method

Buildings of an irregular shape or those that are subject to exceptional conditions are required to be tested in a wind tunnel to determine wind loads. A scaled-down model of the building that includes its most important features is built and controlled flow conditions are applied to measure pressure levels and dynamical response.

So where does CFD come into play? Well, as you might have noticed, CFD analysis is not a valid approach to determine wind loads conforming to the code at this time. However, this doesn’t mean that CFD simulations cannot be of use for architects and designers following ASCE 7. Let’s explore a few scenarios below.

Useful Applications of CFD for Building Design

Although the results of a CFD simulation are not submittable according to the ASCE 7 code (yet), they are still a powerful tool to gain insights into wind flow behavior around the building and estimate pressure loads alongside standard building aerodynamics. It’s also important to note that the majority of codes provide only minimum load levels for common buildings. It is ultimately up to the engineer to judge whether the requirements set by the code are sufficient to guarantee the safety and performance of their building. If it is estimated that special conditions might generate higher wind loads or turbulence (which can cause resonance in a flexible structure or part of it, e.g., the infamous Tacoma bridge collapse), or that the shape of the building demands a deeper flow study, CFD can provide useful and insightful results to help make inform design decisions earlier in the process.

Effect of Surrounding Bodies on Wind Flow

While the ASCE 7 code provides analytical rules that take into account the presence of surrounding objects, such as hills or other high- and low-rise buildings, a more detailed analysis of the effects of certain obstacles on the wind flow can be advantageous to engineers. A CFD simulation can be used to predict and measure effects such as wake characteristics, vortex formation, tunnel throttling, and wind speed and direction at the building of interest.

Turbulence and Vortex Formation and Effects

Given the correct conditions, turbulent instabilities in the flow can develop, deviating the behavior from the analytical laminar case. Corners, discontinuities and high wind speed—among other factors—can trigger seemingly random movements in the flow. Designers can use CFD to predict such phenomena, measure their pressure effects, and assess if it poses a threat to the safety or performance of the building.

Fluid-Structure Interaction

A more advanced type of simulation, fluid-structure interaction analysis allows engineers to take into account the flexibility of the structure and its subsequent deformation due to flow pressure forces. In this way, the analyst can accurately predict dynamical instabilities, unstable motion or dangerous vibration modes induced by the wind load.

Learn how to leverage the cloud-based SimScale platform to optimize your design based on accurate results and ensure pedestrian wind comfort and safety!

Watch Simulation

Preparation for Wind Tunnel Testing

Wind tunnel test experiments are expensive and cumbersome. Ahead of time, preparation and planning are crucial to avoid errors and cost overruns. A virtual wind tunnel test (with CFD) can be performed earlier in the design stage, to determine expected behavior and find realistic estimates of the measurements at the scale to be used in the wind tunnel. Sensor placement and relevant feature modeling can be determined based on simulation results with confidence. Additionally, by having both full-scale and scaled-down CFD models, correlation and extrapolation accuracy can be improved for the physical test measurements.

Assess Pedestrian Wind Comfort

It is usually only after a building has been completed that any wind tunneling and vortex formation caused by its features is discovered. These effects can significantly impact pedestrian wind comfort and in extreme cases, pose a safety risk. With CFD simulation, engineers can predict and measure flow behavior ahead of time, and make changes in the design phase, avoiding late, unexpected alterations and associated costs.

How SimScale is Improving Access to CFD

While the benefits of integrating CFD into the design process are clear, for architects and engineers, uptake has been slow for a number of reasons. Traditionally, CFD tools have been expensive to implement and maintain, difficult to operate and limited in their flexibility.

At SimScale, our aim is to open up access to this technology to a wider range of people and businesses. By leveraging the power of cloud computing, all processing and data storage is done remotely, with automatic security and backups, giving you access to immense processing power at a fraction of the cost. Our platform is accessible on any computer, anywhere, through a web browser, removing the need to install and manage local software and licenses. And, with our free Community account and public reference projects, you can start simulating from day one.

The post ASCE 7: How to Comply with this Building Code and the Role of CFD appeared first on SimScale.

Wind engineering is a very exciting area of knowledge, as it has so many practical applications (some of which we will investigate below), which also turn out to be relevant for many aspects of our daily lives. Some of its benefits are unknown to many people, even though they benefit from it in a significant manner.

Numerical Simulation with CFD

Wind-related technology depends on the ability of engineers to understand and predict flow behavior. This specific requirement fuels the centuries-long quest for equations and rules to model fluid flow, a quest that is still relevant today and poised to drive research for many years to come.

Computational fluid dynamics (CFD) is one of the most important achievements of this research field. Its power resides in the ability to apply physical fluid models to almost any geometry, which is done by leveraging the use of numerical methods and digital computers. And because of this last characteristic, its application power has grown hand-in-hand with the growth in computing power.

But one common limitation that practical applications of CFD have found is related to this very same computing power aspect. Regular workstation computers often lack the required amounts of memory and processing speed to run viable models—this means sufficiently fine, convergent mesh densities of geometrically accurate and detailed models. Simulation engineers then have to rely on approximated and simplified models to carry out their work in a reasonable time, sacrificing the full potential of the technique.

Cloud Computing and SimScale

This problem has led to the creation of supercomputers and parallel computing networks. But these solutions are expensive to implement and maintain, which puts them out of the reach of the majority of professionals. On the other hand, the advent of cloud computing has shed a new light on the matter. Remote Internet computer servers can be put to work for CFD simulations on demand, with high computing power and cost reduction.

The SimScale platform is exactly this! It puts cloud computing power in the hands of engineers in an easy, affordable and reliable way. By leveraging cloud computing, all processing and data storage is done remotely, with automatic security and backups. And it is accessed through the web browser, so there is no need to install and manage local software and licenses. It even has a free Community account and public reference projects to help one test and start simulating right away.

Sign up & check out our SimScale blog for much more!

Read More Now

Wind Engineering Applications 

Below we will present some very exciting applications related to wind engineering, with example projects available on the SimScale platform. By leveraging the CFD technology and cloud computing, wind engineers gain the power to accurately simulate systems for testing, design, and optimization.

Wind Loads on Buildings and Structures

Wind can also be a cause of catastrophes, especially when dealing with human-built structures. High-speed winds pressure over tall buildings, bridges, publicity billboards and the like, can cause collapse and harm people. Construction codes generally present formulas to deal with wind loading, but with complex geometries and surrounding conditions, the case can fall out of the code’s reach and may need further investigation, such as using CFD simulations.

Wind Comfort

Another wind-related source of risk for humans is wind flow around buildings in urban areas. The presence and shape of buildings can create vortexes, turbulence and tunneling effects that can discomfort or even harm people. Often, these effects are only noticed after the building is complete, at which point mitigation is often difficult and expensive. However, with the use of simulation, these issues can be predicted and corrected in the design phase. Our last example project above is a validation of pedestrian wind comfort in a city of Japan.

Wind Energy

Wind energy is a very hot topic nowadays. Although it has been present in many forms for a long time, such as in windmills and sailboats, with the recent rise of renewable energy sources, it has taken a renewed protagonism. With the phasing away of fossil fuels, it is poised to gain even more prevalence. In the example project above, a wind farm is simulated to identify the best placement of the wind turbines.

Conclusion

If you are a wind engineer, you no longer have any excuses for not making use of CFD. With the SimScale platform, you have ready access to the powerful software and hardware needed to tackle any simulation challenge. And with SimScale’s learning resources, example projects and great community, you get even more added value for your projects. So, what are you waiting for? Start simulating today!

To learn how you, as a designer, engineer or architect can benefit from virtual prototyping, download this free infographic!

Download Free Infographic

The post Working in Wind Engineering? Here’s Why You Need SimScale appeared first on SimScale.

Numerical Simulation? Do I Need It?

If you don’t know what it is, I will put it simply: numerical simulation replaces physical testing with experiments performed on a computer. For example, a wind tunnel test is replaced with a virtual fluid test using CFD. Or a structural load test is replaced with a finite element virtual structure. Then, using advanced physics and number crunching, data is processed and extracted to evaluate the performance of the tested subject in terms of deformations, stresses, fluid velocities, temperatures, and the like.

The main advantages of using simulation over physical testing are agility and cost reduction. Models can be changed and tested without the need to reserve laboratory time and wait for prototype fabrication. And as they are run on computers, you can leverage the infrastructure you already have. For cases which demand higher resources than you might have at hand, I will present you a great solution, so stay tuned!

Download Free Infographic

Problems I Didn’t Know I Had!

Modern construction projects are subject to higher demands than ever before. Aspects such as energy efficiency and sustainability, occupants’ comfort, structural performance against earthquake or tsunami loads, and wind loads on high-rise buildings are conjugated with the ever-present quest for cost reduction.

These requirements put enormous stress on the way building projects are carried out by architects and civil engineers. This is especially true for the design phases, which are critical because the earliest decisions have a higher impact and lower implementation costs. But how can we assess the performance of a building that is still at an early stage, such as the conceptual design one? Virtual testing with numerical simulation, of course!

Can This Help Me Improve the Quality of My Job?

If leveraged correctly, virtual testing can provide great benefits to the quality of a construction project. This is because it helps architects and civil engineers to make informed decisions that are based on reliable data. Also, engineering can be carried out beyond what is contemplated in code requirements and calculation formulas, for areas not covered or for more demanding performance.

Virtual simulation unleashes the engineer’s ability to get deep knowledge of the performance of the building and the impact of design variations. Engineers can test whole models or isolated areas, and measure variables in any geometrical location. And when performance criteria are established, multiple design candidates can be tested for optimization purposes. In the end, designers and management can rest assured that the best possible design has been selected.

Discover the SimScale Platform!

Now that you know all the benefits that simulation and virtual testing can bring to your building project, the next question is: how do I get them? I present to you the SimScale platform: a cloud-based simulation tool that can be accessed from anywhere, at any time, through a web browser, and allows you to tackle simulations of almost any size and complexity.

Its benefits over traditional desktop tools include aspects such as the convenience of not having to install and maintain software and licenses; the possibility of using your current computers, as no particularly powerful machines are needed (all number crunching is carried out on remote cloud computers); the reliability of your data being managed in the cloud, with backups and content delivery networks; easy sharing and collaboration among design teams; fast response support, with optional sharing of project data.

Example Applications for Architects and Civil Engineers

The following are some relevant simulations that have been created on the SimScale platform, which should give you an idea of the capabilities of virtual testing and of this platform for architects and civil engineers:

Airflow Around Singapore

In this project, the wind flow around a real city landscape is tested. You can see the scale of the simulation and the practical application if, for example, you would like to design a new structure in the area and want to investigate the influence of the new building or the expected wind pressure levels.

Static Analysis of an Elastomeric Bearing Pad for Bridges

This project tests composite steel and elastomeric bearing pads, as used in a bridge interface to foundations. Advanced material models allow us to take into account the realistic, non-linear behavior of the elastomer. Elements such as these are used for dynamic load-resisting structures, such as vibrations, earthquakes, or wind, and mainly for their high flexibility and fatigue resistance.

Pedestrian Wind Comfort Simulation in a City with CFD

In this project, a computational fluid dynamics simulation is used to examine the impact that the buildings have on wind flow, such as vortex formation and tunnel acceleration. Flow variables are then evaluated at pedestrian locations to assess if they pose a risk to comfort or even safety.

If you’d like to learn more, here is the recording of a webinar about how to evaluate pedestrian wind comfort with CFD by using a standard web browser:

Thermal Comfort in a Theater Room through Ventilation

In this project, two options for the ventilation of a theater are compared to select the best design based on thermal comfort variables. Using this tool, an informed decision can be made in the design phase to select the optimal ventilation strategy, reduce energy consumption, and ensure that performance criteria are met.

This webinar recording gives more information on how to optimize ventilation systems and HVAC components with fluid flow simulation without leaving the web browser.

Conclusion

Architects and civil engineers now have several reasons to start making use of the power of numerical simulation for virtual testing. The SimScale platform offers a very attractive entry point to start learning and testing, with many public example projects that one can copy and modify, a great online community and support, and the possibility to first try the tool for free. with the Community account. Be ready to take your buildings to the next performance level.

Sign up and check out our SimScale blog for much more!

Sign Up Now

The post Things All Architects and Civil Engineers Should Know: Builders Beware! appeared first on SimScale.

One of the main benefits—one I regularly highlight when talking about cloud simulation—is the higher computing power. Sure, it is easy to imagine that a server farm is far more capable of simulating big problems than my laptop, but how does it actually compare?

In this article, I will attempt to compare a number of typical CAE software, their workflows and some rough numbers for their capabilities. Although these will be approximations, they should provide a general indication of the limitations and benefits of each of them.

What are the Benefits of Higher Computing Power for Numerical Simulation?

In a typical numerical simulation with computer-aided engineering (CAE), the underlying technique is to solve a system of equations that describe the physical behavior of a given system. And no matter the technique, the typical solution is to “discretize” the geometrical space of the system. This means that we create a list of points inside the geometry and use those points to locate physical variables, such as pressure, temperature, flow velocity, deformation or stress. Just like having probes or sensors at every point to tell us the value of the quantities we want to know, you can also think of it like a digital picture, where every point (pixel) has a color value.

And just like the digital picture example, the more points you have, the better the approximation will be, which translates directly to memory consumption. For example, in an FEA simulation, we have to solve a system of linear equations, whose size depends directly on the number of points. If, for example, we have a model with three degrees of freedom (three variables) per point—which is the typical case for 3D solid stress simulation—we would get a system of 3*(number of points) equations with 3*(number of points) unknown variables to solve. So the number of “n” coefficients one has to store and handle increases by a power of two of the number of points. On the other hand, solving the system of equations takes between n2 and n3 operations, which the processor has to perform sequentially or partly parallel. You can see that it escalates very quickly.

For that reason, we need computers with more memory that can perform operations faster. This increased power allows us to create more detailed models, with a higher number of variables and maximum precision—something which is particularly important in engineering and design, where the simulation often has to be carried out many times to account for parameter variations. Imagine having a huge, complex system for a given design, where every analysis that is run takes 24 hours to complete on your workstation. How valuable would it be if you could reduce that computing time by four hours, simply by changing the platform the simulation runs on? 

Download this free case study to learn how the SimScale cloud-based CFD platform was used to investigate a ducting system and optimize its performance.

Download Case Study

The Simulation Software Factor

Besides raw computing capacity, there is another factor that determines how much power is available to complete a fast simulation: the software. There is no use in having the most powerful supercomputer in the world if you don’t also have the tools to make the most out of it, or the correct algorithms to solve systems of equations, which is vital to achieving the maximum possible performance.

A lot of research and development has been put into creating programs that solve systems of equations in the fastest and most efficient way, as well as to take advantage of computers with features like multiple computing cores and distributed memory. Additionally, a lot of different optimizations and parameters are available, allowing these programs to tackle different kinds of problems.

That is necessary because of the varying natures of physical systems and models, which is reflected in the final equations to be solved. For example, the equations arising from an elasticity problem are different in nature to a turbulent flow simulation, especially from the point of view of an optimized solver program. So the method used to solve them must be different in order to optimize the performance for every single problem.

The result of this phenomena is that in order to have the fastest possible simulation for your hardware, you have to be able to try different solving programs and tweak the parameters until you find the optimal performance. For that, a more advanced simulation package with these options available is necessary.

Comparison of Computing Resources for Typical CAE Software

In the following table we can see a comparison of typical simulation or CAE platforms and software:

In the first case, we have the cheapest setup, with an average computer and the simulation feature included in your typical 3D CAD package. This package could be convenient for small simulations with low accuracy, but for more involved studies, you might need to upgrade to a full-featured simulation suite.

In the second case, we have a more expensive, full-featured desktop workstation, with a traditional complete simulation suite. With this CAE package, you have good performance capabilities and access to computing optimizations with the ability to perform medium-sized simulations at good levels of accuracy. Larger and more accurate simulations, however, are still out of your reach because of memory size limitations and limited parallelization.

In the third case, an average computer is used to access the SimScale cloud-based simulation platform. With SimScale, you can tackle large CFD or FEA simulations with plenty of computing resources (the asterisk indicates that you can solicit more if you need). Also, the total cost is competitive as, for example, there are no server maintenance or power costs, and there is the option to choose to pay according to your computing power needs.

Conclusion

If you are being held back by the capabilities of your current simulation software, then upgrading to SimScale could be the right solution. In comparison to the technical aspects of the computing power of on-premises, traditional, simulation/CAE software, we can confidently conclude that cloud-based simulation through SimScale is a simple, efficient, and cost-effective option to improve your simulation capabilities. You can give it a try for free here.

The post Limited Computing Power With Your CAE Software? Here’s A Solution! appeared first on SimScale.