Exhaust System Performance Analysis And Optimization Design Of The Ship

Ship exhaust system directly affects the whole ship performance,fuel economy and comfort,not only affect the health of those on board ship noise,but also can cause the ship equipment fatigue damage,and reduce the lifespan of the ship.Ship noise is the main radiation source host,the host of the largest noise from exhaust noise,the main measures in exhaust muffler is installed in the system to control exhaust noise.In the exhaust muffler is installed in the system,can make the system increases the pressure loss,cause the loss of the power performance and fuel economy of diesel engine.Therefore,the research on acoustic performance exhaust system and gas dynamic performance is very important.Early ship muffler research mainly by experiment and empirical formula,the combination of long design period cost is high,and the traditional one dimensional plane wave theory and using the transfer matrix algorithm has larger error.Along with the development of computational science,using professional software for muffler 3-d numerical calculation with the advantages of good,is a reliable method in optimizing the structure of the exhaust system analysis and the muffler.Based on the detailed study of aerodynamic noise under the premise of acoustic theory and fluid dynamics,taking a testing result as the research object of the engine exhaust system,acoustic finite element calculation model and the flow field are established,the application of acoustic analysis software LMS.Virtual Lab simulation and computational fluid dynamics software FLUENT to calculate the transmission loss and pressure loss,got the muffler pressure distribution,pressure and velocity distribution.Respectively on the exhaust system of exhaust noise and the pressure loss of the export of experimental measurements,numerical simulation results are relatively consistent with test data,prove the validity of the numerical calculation,and the sound characteristics of the original exhaust system and aerodynamic performance analysis and evaluation,the transmission loss curve in most frequency noise elimination effect is not ideal,the original unreasonable structural design is put forward concrete improvement project of three,to simulation of the improved muffler,the results show that the improved muffler in the wide-band noise elimination effect is improved,and the exhaust system pressure loss in the range of the standard for the performance of Marine exhaust system design provides an important guiding significance and practical value.