Aerodynamic Noise Similar Relationship and Its Application to Wind Tunnel Test

Abstract:

Based on the sound powers of the basic aerodynamic sound sources (monopole source, dipole source and quadrupole source) radiating to the far field and their relations with the moving speed, the feature size, the distance from the observation point and the media characteristics etc, a conversion formula of the aerodynamic sound pressure level (SPL) radiating to the far field between the model and the prototype was derived. Moreover, the aerodynamic SPL outside the flow for a highspeed train model was measured in an aeroacoustic wind tunnel. Based on the testing results and the conversion formula, the aerodynamic SPL of the highspeed train model at higher wind speed was derived from them at lower wind speeds. At the same time, the correctness of the conversion formula has been verified by the testing data. The studies above show that the conversion formula reveals the relationship of the aerodynamic noise in the far field between prototype and model and plays an important role to analyze the testing results and convert the data in the model experiment.

Key words:aerodynamic noise; aeroacoustic similarity; sound power; aeroacoustic wind tunnel; highspeed train model