基于声扰动方程的旋转圆柱流声数值研究OA

A hybrid acoustic prediction method for rotating boundaries is proposed for the problem of noise bypass-ing a rotating cylinder at low Reynolds number.The finite volume method with acoustic perturbation equation was used to numerically simulate the rotating cylindrical flow-induced noise around a rotating cylinder with Reynolds number Re=160,and the rotational effect of the wall was dealt with by using a slip mesh in combination with an arbitrarily matched interface technique to compute the flow structure and acoustic field distributions for different ro-tational speed ratios.The results show that the simulation results of the rotating cylindrical flow field and acoustic field match the calculated values from direct numerical simulations in the literature,which verifies the accuracy of the hybrid acoustic prediction method;As the rotational speed ratio increases,the mean value of drag coefficient decreases and then increases,and the mean value of lift coefficient increases monotonically.The amplitude of lift resistance fluctuations is significantly higher in the unilateral vortex state compared to the periodic vortex shedding state;The far-field radiated sound pressure level of the periodic vortex shedding state increases and then decreases with the increase of the rotational speed ratio,and the overall acoustic directivity shows a dipole distribution.The far-field radiated sound pressure level rises sharply in the unilateral eddy-dynamic state,and the acoustic directiv-ity is converted to an eccentric circular distribution.