特种车排气消声器多场研究及结构性能分析

Multi-field Research and Structural Performance Analysis of Exhaust Muffler for Special Vehicles

针对某型危险品运输车的排气消声器壳体温度分布情况和外激励是否会引起消声器共振而致使其开裂的问题,运用FLUENT软件对某消声器进行内流场及温度场数值分析,用AR320+非接触式红外线测温仪对消声器壳体温度进行测量,最后基于ANSYSWorkbench以数值分析结果作为预应力对消声器进行模态分析。研究表明:消声器壳体温度仿真值与试验值的误差在5.92%内,间接验证了数值分析的精确性;当尾气流速为6.24m/s时,消声器内部存在涡流,会导致噪声产生;路面激励27.8Hz和发动机激励106.67Hz均低于消声器的1阶固有频率111.01Hz,不会引起共振,但消声器筒体左侧面变形量较大,为18.06mm,为该消声器的薄弱位置。研究结果可为特种车辆消声器的改进设计提供了参考。

In view of the temperature distribution of the exhaust muffler shell of a certain type of dangerous goods transporter and whether the external excitation will cause the resonance of the muffler which may cause the cracking of the muffler or not,the FLUENT software is used to analyze the internal flow field and the temperature field of a muffler.The AR320+non-contact infrared thermometer was used to measure the temperature of the muffler shell.Finally,based on ANSYS Workbench,the pre-stress which were numerical analysis results were used to conduct modal analysis for mufflers.The research shows that the error between the temperature simulation value and the test value of the muffler shell is within 5.92%and the accuracy of the numerical analysis is indirectly verified.When the velocity of exhaust gas is 6.24 m/s,there is a eddy in the muffler which will cause noise.And the frequency of road surface excitation 27.8 Hz and the frequency of engine excitation 106.67 Hz are both lower than the first order natural frequency 111.01 Hz of the muffler,it will not cause resonance,but the deformation of the left side of the muffler cylinder is 18.06 mm which is the weak position of the muffler.The research results can provide solid reference for improving design of mufflers for special vehicles.