Prediction And Experimental Study On Vibration And Noise Of Rotary Vane Compressor

The rotary vane compressor,as the heart component of the automobile air-conditioning system,can suitably adjust the air humidity,temperature and other related comfort indicators in the car,and bring a good driving experience to the driver and passengers,but for a long time,the compressor system has more obvious order noise,which seriously affects the sound quality of the vehicle.In the actual loading and operation,the operating conditions of the rotary vane compressor are complex and changeable,which triggers multi-source time-varying excitation,and the internal flow field,structure field and working medium of the compressor interact,resulting in serious vibration and noise problems in the compressor system,which aggravates the sound quality inside the car.Therefore,it has important theoretical and engineering application value to carry out prediction and experimental research on the vibration and noise of automobile air-conditioning compressors.The thesis takes the rotary vane compressor as the research object,establishes the mathematical analytical model of the compressor internal mechanical contact excitation,the internal flow field air pulsation excitation fluid dynamic model,the whole machine vibration response dynamic model and the acoustic boundary element model,and study the compressor mechanical excitation and air flow pulsation excitation,using it as the mechanical boundary condition,analyze the compressor vibration response and noise distribution law,then build a noise test bench to carry out noise test research,reveal the compressor noise propagation mechanism and distribution law under the action of multi-source excitation.The main research work of the thesis is as follows:(1)A characterization model of the element cavity pressure of a rotary vane compressor is established,and build a gas pressure test platform for comparative analysis,derive the blade rigid body dynamic equation,and calculate the time-varying dynamics between the blade and the blade groove,the blade and the inner wall of the cylinder motivation,the influence of rotor speed,back pressure cavity pressure,blade offset,blade mass and other parameters on the dynamic supporting force and contact force are studied,and the mechanism of multi-body contact excitation of rotary vane compressor blades is clarified.(2)Taking into account the blade tip leakage factor,compile a custom function for blade motion control,establish a computational fluid dynamics dynamic grid model for the suction-compression-discharge process in the compressor flow field,and analyze the change law of pressure pulsation,speed and temperature characteristics of the flow field in the compressor,clarify the excitation mechanism of air flow pulsation in rotary vane compressors.(3)Establish a multi-flexible finite element mesh model that mainly includes rotor-blade-cylinder-end cover-housing,etc.,take mechanical excitation and air flow pulsation excitation as mechanical boundary conditions,and calculate the vibration mode and response of the compressor based on the mode superposition method.Reveal the vibration mechanics characteristics of rotary vane compressor under multi-source excitation.(4)The acoustic boundary element mesh model of the rotary vane compressor is established,extract the time domain response data of the vibration displacement of the shell surface node,and convert it into the frequency domain response as the acoustic boundary condition of the boundary element model,and then carry out the radiation noise of the rotary vane compressor.Set up a rotary vane compressor noise test bench system in the semi-anechoic chamber,carry out compressor noise test,and compare and analyze the calculated value to verify the rationality of the calculation model.