Automotive HVAC unit noise prediction

Passengers’ thermal comfort is mainly provided by the air conditioning system. One important part of this system is placed in the car cabin compartment under dash board. This part is the Heating Ventilation and Air Conditioning Module (HVAC).
Air provided by HVAC is blown from outside or inside the car cabin via a blower, passing through filter, thermal exchangers, mixing chamber and then distributed via duct-systems to different areas. To blow the air inside the cabin, the blower must overcome the pressure generated by the elements inside the HVAC module. Due to this fact, noise is created and its level is directly linked to flow and pressure. VALEO has developed dimensioning tools that predict the overall noise level of the HVAC. However these tools, based on simple calculation and measurements, cannot predict spectrum and sound quality.
In order to address this weakness, Valeo is aiming, though CEVAS project, to develop a prediction tool which will provide spectrum and sound quality data. This tool will be based on CFD simulations, aeroacoustic experimental measurements, Particle Image Velocimetry and acoustic synthesis methods.