Experimental Study Of Automobile Swirl Exhaust Device Based On AVL Fire

A new method is pulled out for the problems such as poor exhaust,low inflation efficiency and high emission when the car running in the congested roads of the city.This new method can improve the inflatable efficiency by increasing the negative suction in the exhaust pipe and speeding up the gas emissions.Taking the LJ465Q engine exhaust system of a small passenger car as an example,a swirl exhaust device which has the characteristics of generating local low pressure zone and accelerating gas several times is designed.Then,the method of CFD technology and engine performance test is used to verify the feasibility and effectiveness of the structure design.The structure of swirl exhaust device bases on the working principle and structural characteristics of the venturi and ejector,and combines the existing exhaust system.Using the UG software to establish the gas flow channel model of the device.And the AVL Fire software was used to simulate the flow field distribution in the swirl exhaust exhaust.So the specific distribution of the velocity and pressure of the flow field was obtained so as to judge whether the device meets the design requirements.And then the model is trial-produced according to the simulation results.According to the purpose of the test and related requirements of GB/T18297-2001 "Automotive Engine Performance Test Method",the pressure and temperature-related measuring instruments are selected and installed for building a complete test bench.Then installing the swirl exhaust device to the exhaust system of LJ465Q engine.And the comparative experiments are done on the engine test bench.At last,the parameters such as engine power,torque,fuel consumption,emissions and intake pressure are compared and analyzed.The results show that the swirl exhaust device can accelerate the exhaust emissions,increase the intake pressure,improve the charging efficiency and the performance of the engine.And the effect is most obvious when the 50%throttle opening:the intake pressure average increases by 4.2%,the output torque increased by an average of 2.2%,the output power increased by 3.4%on average,fuel consumption rate decreased by an average of 1.1%,the contents of HC,CO and NO in exhaust gas are reduced by 8.9%,6.4%and 3.2%respectively.