拖拉机分流气体对冲排气消声器压力损失的研究

Study on Pressure Loss of Exhaust Muffler for Tractor Exhaust Gas

对课题组前期提出的拖拉机分流气体对冲消声器进行了内流场的优化与改进,运用CFD软件Fluent对原消声器进行了流场计算。分析发现:隔板及对冲区域是压力损失比较大的地方,其原因在于结构设计不合理引起的速度梯度的急剧变化。在自行设计的消声器试验台上,对原消声器进行了不同速度入口条件下的压力损失试验与仿真对比,结果表明:通过CFD方法可以很好地模拟消声器的压力损失,且消声器的压力损失随入口速度的增大而增大;对原模型进行结构改进,通过增加导流环、加大弯头半径等方法,消除了容易产生速度梯度的负压区,改进后的消声器压力损失比改进前的压力损失减小了30%左右。

The split-stream-rushing collision of tractor muffler research was optimized and improved internal flow field,Using CFD software Fluent to calculate flow field of the muffler,Based on the results of analysis showed that the collision and baffle area is relatively large pressure loss of the place,and analyzes the reasons for relatively large pressure loss is a drastic velocity change of the structural design is not reasonable,the test rig is designed on the comparison of pressure loss test and Simulation of different entrance velocity conditions under the original muffler,pressure loss of muffler uesd by the method of CFD simulation can be test good,The pressure loss of muffler increases with the increase of inlet velocity,to improve the structure of the original model,by increasing the guide ring,increase the bend radius and other me thods,The negative pressure zone which is easy to produce velocity gradient is eliminated,and the pressure loss of the improved muffler is reduced by 30%.