The Simulation Research Of The GD190 Diesel Engine Test-bed Exhaust System Based On One-three Dimensions Coulping Caculation Technology

Engine bench test is an important test method to the research and development,production,maintenance and use of the engines.The structure of Engine test bench exhaust system is related to the accuracy of the engine bench test.It determines the engine's quality of the gas exchange process,charging efficiency,and utilization of exhaust pressure wave.Especially the exhaust pipe joint is the important part to connect the engine exhaust export and the bench exhaust pipe,its structure has a big impact on the exhaust flow characteristics during the commissioning process.Then it will affect the measurement result of engine performance index.The exhaust performance of the test bed's exhaust system is so important for engine performance test,but which is often neglected by people.Based on that GD190 diesel engine still has the problem of poor performance test,this paper has an intensive study on the engine test bed's exhaust system with modern CFD simulation technology.First of all,to make the diesel engine performance tests on the test-beds with differently structured pipe joints and comparative analysis the influence of exhaust pipe connector on measurement result.From the point of comparison results,the modified exhaust pipe joint with original structure makes the measurement accuracy of test-bed reduce greatly.Secondly,based on the software FIRE,making 3D steady state simulation on the exhaust system gas flow of test-beds with the original exhaust pipe joints and modified exhaust pipe joints to research the circulation features and internal structure of test-beds' exhaust system.Finally,optimize the structure based on the slide type exhaust pipe joint,not only analyze the flow characteristics of the gas in the exhaust system of test-beds with steady-state calculation based on software FIRE,but also compare the advantages and disadvantages of the engine,which is matched different exhaust systems,based on the three-dimensional coupling calculation with BOOST and FIRE software.According to the comprehensive analysis of structure calculation and the experimental results,the performance of the exhaust system of test-bed with the optimized exhaust pipe joint 3 is better than the other three kinds of exhaust system.Tests show that the exhaust pipe joint optimization can improve the accuracy of the test bench testing not only for the GD190 diesel engine,but also for other models test.In this study,the one-three dimensional coupling technique is applied in the transient analysis for the test-bed exhaust system to improve its circulation characteristics and provide theoretical foundation for raising the accuracy of engine performance test with the test-bed.