Analysis Of Flow Field And Fluid-Structure Interaction In Exhaust Gas Turbocharger About The Diesel Engine

Turbocharged technology has become one of the most effective ways to imrprove the efficiency and reduce the engine emissions.Turbocharger is always in high tenperature and speed,also under the conditions of changing conditions.And the impeller bears a variety of toad effects.So it is very important to simulate the internal flow field of the turbocharger,and the fluid structure interaction analysis of the spiral case and the impeller.For the turbocharger,the following work is done in this paper:(1)The three-dimensional model of GJ150 diesel engine turbocharger was established using Solidworks software.According to the working conditions of diesel engine,it is the assumption that the oxygen consumption of the engine is 90%,85%and 80%of air.According to the three conditions,three conditions were set.By the regression equation,the thermodynamic parameters of the waste gas of three kinds of conditions were calculated,which are constant pressure specific heat,density,dynamic viscosity and thermal conductivity.(2)The numerical simulation of the internal flow field of the turbocharger was carried out according to the three conditions using Fluent software.And the pressure field,tenperature field and velocity field distribution of the gas in the middle section of the turbocharger were analyzed.The relationship between the velocity,temperature and pressure in the thermodynamic parameters of exhaust gas and the internal flow field was analyzed.(3)According to the result of the analysis of the flow field,the pressure load and temperature load are loaded onto the inner wall of the spiral case.Centrifugal force load,pressure load and temperature load of impeller were loaded on the surface of impeller.Numerical calculation of fluid structure interaction between the casing and the impeller was built.And the results of fluid structure interaction between the spiral case and impeller were analyzed.(4)According to the results of fluid solid coup ling calculation,the root structure of the impeller was optimized.And the impeller was calculated by fluid structure interaction.The equivalent stress and equivalent deformation of the impeller before and after optimization were compared and analyzed.The results show that the equivalent stress and the equivalent deformation of the optimized impeller are reduced,and the structure of the impeller is optimized.