Aerodynamic Sound Source Identification Method Based on Flow Around Cylinder

Abstract:

Taking the aerodynamic sound source generated by the airflow flowing through the solid surface as the research object， based on the acoustic wave equation’s solution of dipole sound source corresponding to the force point source， according to both the relationship between the pressure of the sound source and the pulsation force and the relationship between the pulsation force and the pressure gradient in the flow field， the relationship between the pressure of the dipole sound source and the pressure gradient in the flow field was established. Based on the concept that two dipole sound sources can form a quadrupole sound source， the relationship between the pressure of quadrupole sound source and the pulsation velocity of flow field was also established. Finally， taking the flow around cylinder as the research object， the strength and distribution of the dipole and quadrupole sound sources of the flow around cylinder were obtained with a combination of the above two equations and the numerical simulation method. It is shown that the pressure of the dipole sound source to the far field is determined by ??p?t， and the pressure of the quadrupole sound source to the far field is determined by ?2ur2?t2.

Key words:aerodynamic sound source;dipole sound source;quadrupole sound source;flow around cylinder;computational fluid dynamics