GPU-Accelerated Aeroacoustic Simulations of HVAC Duct Configurations

Large eddy simulations (LES) of two HVAC duct configurations at different vent blade angles are performed with the GPU-accelerated low-Mach (Helmholtz) solver for comparison with aeroacoustics measurements conducted at Toyota Motor Europe facilities. The sound pressure level (SPL) at four near-field experimental microphones are predicted both directly in the simulation by recording the LES pressure time history at the microphone locations, and through the use of a frequency-domain Ffowcs Williams-Hawking (FW-H) formulation. The A-weighted 1/3 octave band delta SPL between the two vent blades angle configurations is also computed and compared to experimental data. Overall, the simulations capture the experimental trend of increased radiated noise with the rotated vent blades, and both LES and FW-H spectra show good agreement with the measurements over most of the frequency range of interest, up to 5,000Hz. For the present O(30) million cell mesh and relatively long noise data collection of 0.5s, the simulation results can be obtained in about 6 hours on 8 standard GPUs. Accurate and efficient numerical predictions of the SPL from HVAC ducts would allow automotive manufacturers to assess different duct configurations in the early design cycles and avoid the costly countermeasures necessary when excessive noise is observed in the experimental phase of the final design.