| The turbocharger increases the density of the air by compressing the air to make the fuel more fully burned,increasing the power while reducing the fuel consumption,so it is widely used in internal combustion engines.As a part of the compressed air in the turbocharger,the compressor is the goal that engineers have been pursuing by optimizing the design to achieve better performance.This paper carried out a simulation study on a marine turbocharger compressor,determined the pre-tightening force of the compressor impeller tie rod through theoretical methods,judged the clearance value under this pretightening force through the finite element method,and analyzed the on-axis The flow field law inside the compressor under the direction of pre-tightening force and complex load.This article first introduces the relevant theoretical knowledge of fluid analysis to provide a theoretical basis for the subsequent flow field analysis,and then establishes the compressor fluid domain calculation model through the compressor impeller geometry model,and then imports the calculation model into CFX to analyze the results.The temperature field on the surface of the compressor impeller is coupled to the surface of the supercharger for structural analysis,and the stress and strain of the compressor impeller can be obtained.The gap value between the nut and the compressor impeller is used to judge whether the nut and the impeller are separated.On this basis,the modal analysis of this model of the compressor impeller is carried out.The research results of this paper show that,under rated conditions,the flow conditions inside the compressor are more in line with the actual working conditions,and the temperature field results obtained by the flow field analysis also fit the temperature values measured during the actual operation of the turbocharger..Under the comprehensive consideration of the three loads of centrifugal force,aerodynamic force and thermal stress,the stress and strain results of the compressor impeller are more reliable.Analysis of the results shows that the compression nut and the compressor impeller are in a compressed state.The campbell diagram of modal calculation can find that the 2 octave frequency and the 1st order,the 4 octave frequency and the 2nd order have intersection points,so resonance may be excited and high cycle fatigue.The initial blade mode diagram shows that the blade tip has bending vibration.Its frequency is1887.7HZ,which is 3.63 times the fundamental frequency of the impeller(520HZ),which meets the requirements of CN experience value.The mode value of all blades and discs is 4.4 times the fundamental frequency.The impeller blade mode diagram Harmonicindex=0,mode is 5.It can be seen that the vibration mainly occurs on the blade tip of the main page,and it is manifested as a bending-torsional coupled vibration,which is also considered to be caused by the air intake. |
