VNT系统刚柔混合体动力学分析

Dynamic Analysis of Rigid and Flexible Mixture of VNT System

涡轮增压器由于其改善发动机排放、提高燃油经济性、降低油耗等优点,已在汽车发动机上得到应用,尤其在0.9L~3.0L的柴油发动机中被广泛应用。为了更好地分析并优化涡轮增压器的性能,本文针对可变喷嘴涡轮增压器(VNT)系统进行仿真分析以及刚柔耦合动力学分析。在分析过程中,建立了系统的几何模型,进行了有限元网格划分,处理了边界条件并施加载荷,进行了后处理流程。在整个机构的运动过程中,观察到最大等效应力开始逐渐升高,接着下降,中间过程趋于稳定。然而,当运动到极限位置时,轮叶与Unisson环完全卡住,等效应力又迅速上升。此外,当曲轴转到7°~8°时出现峰值应力。当曲轴旋转至极限位置时,在最大等效应力迅速上升的同时,旋转驱动的力矩也迅速上升。

Turbochargers have been widely used in automotive engines,especially in 0.9L-3.0L diesel engines,due to their advantages of improving engine emissions,improving fuel economy,and reducing fuel consumption.In order to better analyze and optimize the performance of turbochargers,this paper conducts simulation analysis and rigid-flexible coupling dynamics analysis for the Variable Nozzle Turbocharger(VNT)system.During the analysis process,we established a geometric model of the system,performed finite element mesh division,processed boundary conditions and applied loads,and performed post-processing procedures.During the entire motion process of the mechanism,it was observed that the maximum equivalent stress began to gradually increase,then decrease,and the intermediate process tended to stabilize.However,when the motion reached the limit position,the vanes and Unisson rings were completely stuck,and the equivalent stress rapidly increased again.In addition,a peak stress appeared when the crankshaft turned to 7°-8°.When the crankshaft rotated to the limit position,the maximum equivalent stress rapidly increased.At the same time,the torque of the rotary drive also rises rapidly.