基于径向热变形的滑阀滞卡数值研究

液压滑阀常常在使用过程中伴随着黏性加热现象,这将严重影响液压滑阀的控制特性。为了揭示滑阀的热失效故障,建立带有配合间隙的滑阀热特性模型,运用COMSOL软件内置的共轭传热与粒子追踪模块通过求解滑阀热特性模型,对液压滑阀内的流动与传热过程进行数值解析。结果表明:高温主要出现在速度梯度较大的区域以及受高速油液冲击的节流槽壁面;由此导致滑阀配合边上产生不均匀径向热变形,固体颗粒物在发生变形的间隙更容易聚集,由此可知,滑阀配合边的径向热变形对颗粒物的污染卡紧有促进作用。这些研究成果为工程技术人员对液压滑阀卡紧现象提供可视化的理解。

The numerical research on spool sticking induced by radial thermal deformation

The hydraulic spool valves are usually equipped with viscous heating effect in the entire operating process, which has significant impact on controllability of spool valve. In order to present the thermal fault of spool valve, the integrated thermal model for spool valve with fit clearance was established, numerical investigation for thermal characteristics of spool valve had been carried out by settling integrate thermal model with help of Conjugate Heat Transfer Module and Particle Trajectory Module in COMSOL code in this thesis. The result indicated that, the high temperature mainly appeared at the zone with larger velocity gradient and the surface of spool groove impacted by the high velocity flow. The non-uniform radial thermal deformation occurs on matching edges of spool valve caused by temperature gradient. The solid particles gather densely in pressure groove more easily after deformation. By these token, the radial thermal deformations of matching edges provide positive effect on the contaminant lock. These verdicts provide the engineers with a visualization comprehension for the phenomenon of spool thermal clamping.