Calculation And Analysis Of A New Type Of MPC Exhaust Pipe For A Diesel Engine

In recent years,oil,a kind of non-renewable resources,has been facing the crisis of drain.This phenomenon is increasingly obvious.Besides,the crisis of destroyed environment is becoming more and more serious.Therefore,saving resources is appealed around the world.Protecting environment is hanging over our head.Our country formulated higher emission standard: internal-combustion engine as driving force should not only discharge up to the standards,but also save more energy and have stronger dynamic.With regard to the impact of internal-combustion engine on the atmosphere,we think of emission firstly.The exhaust system not only affects the emission of waste gas,but also affects the performance of the engine,especially the supercharged engine.The turbochargers use the power of waste gas to improve the air input.The exhaust system is a very crucial assembly to the crude oil engine.So the most suitable exhaust system should be designed and chosen aiming at each kind of the mode.Now the advent of internal-combustion engine has been more than a century.The research methods of exhaust system become more and more advanced because of people's continuous effort.The previous researchers did a lot of experiments to design the exhaust system of the engines through experience,which was unable to meet the requirements of development now.Nowadays,the technology of computer simulation is becoming more and more advanced.Using software to simulate fluid-flow has become the main research method.We can build a virtual prototype of 3D fluid of the exhaust system on the software platform to analyze the flow field,and then combine this step with the test,which can make the design of the exhaust system more perfect,gain more profit and meet the standard.The exhaust system of diesel engine and virtual prototype of three-dimensional fluid of MPC exhaust system were established in FLUENT and the distribution of flow field was calculated and obtained.In order to get closer results to the actual work,setting up boundary conditions and parameters is particularly important.In this paper,calculation model of 6265 diesel engine was established on the GT-Power platform,the parameters in the model were determined according to the drawing sheet and experimental data.Then the author simulated the working process of this kind of diesel engine,and provided the boundary conditions and the basic parameters for the three-dimensional flow calculation.After setting up the boundary conditions,adjusting the parameters and completing simulation calculation,the author did a comparative analysis of the distribution of flow field of the outdated exhaust system and the MPC exhaust system.Then,the rationality of the design of MPC gas vent was evaluated,calculated and validated again in order to make the optimizing model by adjusting caliber of main pipe and angle.The model of the finite element was established by ANSYS.The analyses of the free modality and constrained modality of the optimizing model were carried out.As a result,the vibration deformation and natural frequencies of MPC exhaust pipe were obtained.By comparing and analyzing the research results,we can conclude that the exhaust pipe will not resonate with the engine.