Study on Aerodynamic Noise Numerical Simulation and Characteristics of Safety Valve Based on Dipole and Quadrupole

Abstract

Aiming at the problem that it is difficult to accurately predict the aerodynamic noise in the safety valve exhaust process, a new numerical simulation method that comprehensively considers the dipole sources and the quadrupole sources is proposed. The RNG k–e model is used to simulate the steady-state flow fields, LES numerical method is used to simulate the transient flow, and then the unsteady disturbances are used as source terms in the generalized FW–H solver incorporating the dipole and quadrupole terms to solve for the acoustic field. This simulation method is used to calculate the exhaust noise of the safety valve under six different operating conditions, the sound source characteristics of the exhaust noise of the safety valve are analyzed, and the safety valve exhaust test of different working conditions was carried out. The results show that the relative errors of total sound pressure level between simulation and test does not exceed 5% under different exhaust pressures and different opening heights of the safety valve flap. By comparing the total sound pressure level logarithmically superimposed with the total sound pressure level of the dipole and the quadrupole, the sound source characteristics of the aerodynamic noise of the safety valve are mainly dominated by the sound source of the quadrupole. As the opening height of the safety valve flap and exhaust pressure increase, the total sound pressure level of the safety valve exhaust noise increases, while the relative errors between the simulation results and test data decrease. The proposed simulation method can be accurately applied to the prediction of the safety valve exhaust noise, and the prediction accuracy of this simulation method also increases when the opening height of the safety valve flap and exhaust pressure increase.