In the thermal expansion valve (TXV) refrigerant system, transient high-pitched whistle around 6.18 kHz is often perceived following air-conditioning (A/C) compressor engagements when driving at higher vehicle speed or during vehicle acceleration, especially when system equipped with the high-efficiency compressor or variable displacement compressor. The objectives of this paper are to conduct the noise source identification, investigate the key factors affecting the whistle excitation, and understand the mechanism of the whistle generation. The mechanism is hypothesized that the whistle is generated from the flow/acoustic excitation of the turbulent flow past the shallow cavity, reinforced by the acoustic/structural coupling between the tube structural and the transverse acoustic modes, and then transmitted to evaporator. To verify the mechanism, the transverse acoustic mode frequency is calculated and it is coincided to the one from measurement. In the end, the recommendations for preventing the system from having whistle are also provided.
Flow-Induced Whistle in the Joint of Thermal Expansion Valve and Suction Tube in Automotive Refrigerant System
Sae International Journal of Passenger Cars. Mechanical Systems
Sae Int. J. Passeng. Cars - Mech. Syst
SAE 2015 Noise and Vibration Conference and Exhibition ; 2015
Sae International Journal of Passenger Cars - Mechanical Systems ; 8 , 3 ; 973-976
2015-06-15
4 pages
Conference paper
English
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