Structure Airborne Noise Control Research Of Engine Based On Simulation

Along with the development of social economy,the automobile has become a common consumer goods,automotive consumers focus on the car's performance more and more critical.Besides dynamic and fuel economy performance,NVH(Noise,Vibration,Harshness)has become an important indicator of measuring the quality of a car.And the engine is one of the key factors affecting the vehicle NVH performance.Noise is the most common and universal topic in NVH filed,and the engine noise is the base source of the vehicle.Regarding the control of engine noise,experiment method was used in the past,the noise level can be tested and the countermeasure would be raised up after test.This method is suitable for the engine development in the past,but nowadays,the performance of the engine and the requirement of planning are more critical,we must do the fast,efficient and precise design in the beginning of project,so that the timing can be guaranteed in the development phase.This paper refer to one kind of engine noise method based on simulation.comparing with traditional method which is based on test can save more time and cost,because of it can predict the noise performance in the early phase of development.This paper research the complete procedure and method of engine radiation noise.Firstly based on the one dimensional no steady flow theory and finite volume method,study the engine thermal performance and get the in cylinder pressure.Then based on multi body dynamic,study the valve train,piston con-rod,crankshaft and flywheel system.then based on multi dynamic and finite element analysis,study the surface vibration of engine.At last,based on boundary element method,study the air radiation noise.The objective of the research is one turbo charged cylinder direct injection engine.Due to the high performance,the noise issue is critical.The prediction in early phase can reduce the pressure and risk in the next phases.The paper predict the engine noise level,and based on correlation between test and simulation,guarantee the precise of the model.At last,based on the simulation results,the paper propose the countermeasures.In the test verification,the results show the precise of the simulation with a tolerance of 1dB(A).This paper shows that the method based on the simulation is valid and efficient.Based on this method,we can solve the noise issue occurred in the development and make sure the development goes well.Meanwhile,in the following engines development,this paper offer the basic method of noise control which has significant meaning.