基于COMSOL的滑阀流固耦合共轭传热仿真研究

液压滑阀在工作过程中常常因黏性加热而出现阀芯热卡紧现象,基于流固耦合共轭传热方法,运用COMSOL软件对滑阀内的热-流-固多物理耦合场进行数值计算。结果表明:高温主要集中在速度梯度较大的区域以及受高速油液冲刷的节流槽壁面,由此产生的阀芯节流槽区域径向不均匀环状凸起变形可能直接导致阀芯卡紧;阀芯最大径向热变形量可达1.31 μm,位于节流槽矩形工作边处;黏温特性对滑阀内的黏性加热效应具有消极的影响,含气泡油液却与此相反,导热率与温度的线性关系对滑阀阀芯径向热变形也具有消极的影响;考虑以上因素并不改变滑阀内的温度场分布与热变形特征,而是使计算结果更加符合实际工况。

The Simulation Investigation on Fluid-solid Coupled Conjugate Heat Transfer for Spool Valve Based on COMSOL

The thermal clamping fault of spool induced by viscous heating during operation of hydraulic spool valve always occurs. Based on the fluid-solid coupling conjugate heat transfer method, the numerical calculation on thermo-fluid-solid multi-physical fields inside the spool valve is carried out by COMSOL. The results indicate that the high temperature mainly appears at the zone with larger velocity gradient and the surface of spool groove impacted by the high velocity flow, and causes the radial annular embossing in spool groove zone to spool clamping. The maximum radial thermal deformation of spool comes up to 1.31 μm in the rectangle edge of groove. Furthermore, the viscosity-temperature characteristics have a negative influence on the viscous heating effect inside the spool valve, but the oil contains with bubbles is opposite. The linear relationship between thermal conductivity and temperature also has a negative impact on the radial thermal deformation of spool. That taking all above factors into account can make the results more conformed to the actual working conditions but make no difference to the temperature distribution and thermal deformation characteristics.