Ducts are a key component of HVAC systems to ensure proper movement of airflow within a building. Whether cooling a residential or commercial building, removing pollutants from a factory, or extracting smoke from an underground parking garage, designing ductwork or an efficient HVAC system makes all the difference in ensuring thermal comfort, proper indoor air quality, and energy efficiency within a building.
When it comes to duct design, common objectives are to optimize airflow through the duct and minimize pressure drop between the inlet and the outlet. To achieve these objectives and create an optimal ductwork design, computational fluid dynamics (CFD) simulation is normally used for virtual testing, as it gives three-dimensional insights into the airflow field and lets engineers investigate the whole CAD model. In recent years, cloud-based simulation solutions such as SimScale have emerged, which allow a full CFD study to be conducted in a standard web browser and multiple design iterations to be tested in parallel, without blocking any local resources.
Case Study: Glanzner Dynamics Improves a Duct Design and Reduces the Number of Physical Prototypes by 90% with Online Simulation
Based in Germany, Glanzner Dynamics is a design company that uses modern computer-aided design (CAD) and simulation solutions to provide high-end engineering solutions to its clients. For one of their projects, the engineers at Glanzner Dynamics used CFD simulation with SimScale to virtually test the design of a new exhaust pipe for a ventilation system.
An initial design was believed to have an issue; the airflow would likely produce high levels of noise due to flow vortices and turbulent fluctuations. To tackle the problem, a second design version with a modified airflow pathway was required.
Sebastian Glanzner—the engineer responsible for this project—designed the inner geometry of the HVAC duct with the cloud-based CAD tool Onshape and simply imported it into SimScale for simulation via the Connector App. A mesh of one million volumes was then generated, the inlet and outlet conditions were defined, and the simulation ran.
When Sebastian inspected the first results of the simulation, he observed that the flow was less than optimal, as multiple vortices and an increase in flow velocity were identified. He then created different design versions and ran several CFD simulations in parallel with SimScale, aiming to identify the one that would deliver the best airflow behavior while maintaining low noise levels.
CFD simulation results of the duct design showing airflow velocity (Source: SimScale, Glanzner Dynamics)
The CFD results showed the best way to solve the problem: inserting pipe segments in order to create a curve in the duct, which would need to have an optimal shape that would slow down the flow and prevent the formation of any recirculation areas or vortices.
To discover the entire case study and the additional duct design improvements made by Glanzner Dynamics using online simulation, you can read the original story here.