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Aerodynamics Simulation for Design

External aerodynamics simulation plays an important role in modern automotive design. Vehicle fuel economy, stability, engine cooling, interior cabin noise and windshield-wiper performance are all influenced by aerodynamic forces.  For decades, automakers around the world have relied upon time-consuming wind tunnel experiments and computational fluid dynamics (CFD) simulations to study the aerodynamic loads on their vehicles.  Today, fast computer systems and sophisticated numerical methods allow the investigation of complex flow structures in a much more acceptable turnaround time. While wind tunnel testing is still an essential step in the automotive industry, aerodynamics simulation employing CFD is becoming more and more popular, reducing the number of physical wind tunnel experiments during a vehicle’s development process.

Performing wind tunnel simulations is typically not a simple task. From model preparation, to meshing and CFD case setup, to simulation and post-processing, the entire workflow can be a complex and time-consuming process. The external aerodynamics flow field of an automobile is determined by very complex geometries (e.g., engine compartment), non-stationary boundary conditions (e.g., rotating wheels and moving ground) and a turbulent flow field, especially in the wake of the vehicle. A streamlined process and vertical application environment, along with an accurate, scalable and robust CFD solver are all crucial elements to enable efficient and mainstream use of wind tunnel simulations.

AcuSolve® is the CFD solver within the Altair HyperWorks® suite, enabling steady state and transient simulations to help predict aerodynamic performance.  HyperWorks Virtual Wind Tunnel™ offers advanced meshing, high-fidelity CFD simulation, and powerful reporting in a single user interface with AcuSolve at its core.  It is possible to import surface mesh, set up the problem, submit the simulation, and obtain a final report using a minimal number of parameters.  This represents a significant improvement in the automotive workflow, and demonstrates Altair’s commitment to providing cutting edge simulation tools.

Using aerodynamics simulation for product design has become a reality in industries beyond automotive.  Companies with short development cycles are working within extremely limited execution timeframes and need to test many different designs as well as benchmark those of competitors.  Simulation has become a critical success factor.

Lx Sim, an engineering firm in Quebec, profiles its use of AcuSolve for precise drag measurement in support of the design of an aerodynamic road cycling helmet in this video, enabling speedy design iterations and optimizing the final design solution to meet exacting performance standards.  You may view the presentation details here.  The firm was able to speed up the development time of the helmet while improving its performance, producing low drag with excellent ventilation.  These examples bode well for increased and broader adoption of aerodynamic simulation for product design in future.