Silent-Aire cuts their product development and testing time and cost by half.

The Challenge

Pre-testing the Performance of AHUs

This case study is based on a live research project to develop and test a novel HVAC unit’s mixing performance under various airflow and temperature conditions applied to the model. The main purpose of the simulation analysis was to validate the mixing performance of the air handling unit (AHU) when part of the airflow was bypassing an evaporative cooling system within the AHU itself. The critical design condition was that no parts of the downstream airflow should vary more than ±0.8°C versus the average supply air temperature. This was to replicate actual operating conditions in the client’s critical facility.

This analysis was designed in such a way to match the real factory witness testing (FWT) that would be carried out on the first-of-kind prototype unit as closely as possible. This FWT test unit had 24 temperature sensors installed within it, in the same locations as the 24 probe points added in the SimScale simulation, giving a true digital twin capability. Due to the high number of units required by the client (320 AHUs for the first two projects) their performance needed to be validated and verified before the design could be signed off on by the client’s engineering consultants and before the first prototype could be built.

The ability to pre-test the AHU performance in SimScale was considered a crucial step in de-risking the development of novel features in a high-performing HVAC unit in a critical facility. Silent-Aire modeled several different internal layouts to see what design would yield the optimum mixing performance.

How They Solved It With SimScale

Digital Prototyping with Cloud-Native Simulation

Lead Mechanical Design Engineer, Shane McConn, has been driving the adoption of SimScale in the engineering design team. Shane had some prior CFD experience, yet remarks on how intuitive and easy to use the SimScale interface is. Shane started with the free trial version originally, a great way for engineers to get started with SimScale. He started using the template projects in the public library and was quickly able to set up, run, and visualize simulation results. Shane has been particularly complimentary of the visual outputs from SimScale, describing them as important for communicating the results to their clients.

The main benefits to Shane and his team include:

• The ability to test designs before they spend money on building prototypes. He considers his team moving towards a more seamless digital prototyping workflow. The additional benefit of converging on a near-final design in SimScale therefore significantly reducing the amount of physical prototyping time and cost is fundamentally changing how the engineering design team works. Previously, the team would have multiple designs and numerous iterations for each design that needed physical prototyping using external consultants. The process used to take months and cost significant money. Now, with SimScale this prototyping stage has reduced to just two weeks.
• More confidence in the final design model as it has been validated. The first-of-kind physical unit is now better converged on a final solution.  
• Significantly reduced number of issues and faults they find in first-generation build units, as more validation has been completed at the design stage.
• Creating a digital twin of the test rig in SimScale to replicate approved testing procedures according to international standards.

THE RESULTS

Saving Time and Money with Simulation in the Cloud

A typical development process before Silent-Aire embedded simulation in their workflow would have included building an initial test unit with a 4-6 week pre-testing phase and 85 engineering man-hours needed to test/optimize the design.

Using SimScale this same process now takes 2-3 weeks of pre-testing and only 40 engineering man-hours. Using simulation, Silent-Aire has cut their product development and testing time and cost down by half (50%) on recent projects.

Silent-Aire is expanding access to SimScale across the engineering team. Graduate engineers are being trained by SimScale and this will enhance the rapid digital prototyping capabilities at Silent-Aire moving forward. With multiple users, Silent-Aire will also benefit from the built-in collaboration and enterprise features that streamline simulation user management and administration, as well as support to automate simulations using the SimScale API.