轴向柱塞泵内不稳定流动及流致噪声特性研究OA

To address the difficulty in predicting flow-induced noise due to complex unsteady internal flow in axial piston pumps,a fluid-structure-acoustic multi-field coupling method is proposed to systematically analyze unsteady flow,housing vibration,and flow-induced noise.Firstly,the Smagorinsky large eddy turbulence model is adopted,with pistons and cylinder block set as rotating domains.The reciprocating motion of pistons is simulated using moving mesh and kinematic equations.Secondly,based on Lighthill's acoustic analogy,flow stress tensors and normal mass flow are mapped onto the acoustic mesh as acoustic sources.Vibration excitation is defined using sound pressure and the normal vector of the housing surface.A COMSOL multiphysics coupling model is then constructed.An experimental platform is built to validate the algorithm.Results show that oil flows out as a jet from the damping grooves of the valve plate.Sudden changes in pressure and velocity induce pressure pulsations,which act on the inner wall of the pump housing,excite housing vibration,and radiate flow-induced noise.The internal fluid sound source peak reaches up to 160 dB,but noise significantly attenuates through pump structure transmission,with radiated housing noise dropping to about 40 dB.Flow-induced noise exhibits wideband characteristics across the entire frequency range,and sound pressure level gradually decreases with increasing frequency.The measured total sound pressure level of housing-radiated noise is 63.79 dB,while the numerical simulation result is 53.43 dB.The close agreement validates the accuracy of the proposed method.