基于CFD的两级气动直接力控制阀静态特性

Static characteristic of two-stage aerodynamic direct-force control valve based on CFD

通过对一种两级气动直接力控制阀进行结构参数设计和基于计算流体力学(CFD)的静态特性仿真研究,比较分析了前置级阀挡板及主阀芯在不同位置时阀腔内流场的流动状态和压力损失情况并提出优化措施,得到了挡板位置-流量特性曲线和位置-气动力特性曲线、主阀芯位置-流量特性曲线以及主阀输出推力。利用推力测量试验台进行了原理样机的热试,实测结果与仿真结果基本一致,证明了对两级直接力控制阀的静态特性分析是准确的。分析结果表明,在入口压力保持不变的情况下,前置级阀挡板及主阀芯开口度增大,喷管的输出流量也增大,处于中位时两喷管输出总流量最大;当挡板自中位向极限位置运动时,气动力逐渐增大,是帮助挡板运动的主动力,反之恰好相反;该阀输出的644N大推力完全能满足导弹控制系统的要求。

By structural parameters design of a kind of two-stage aerodynamic direct-force control valve and by investigating the static characteristics based on computational fluid dynamics(CFD), comparative analysis has been made on the flowrate and pressure loss of the flow field in the valve cavities when the prestage valve flapper and the main valve spool were in different positions. In this way, the optimized measures have been proposed, the position-flow and position-aerodynamic force characteristics of the flapper, and the position- flow characteristic of the main valve spool have been obtained, with reduced output force of the main valve. Hot test of the theoretical prototype has been made on the thrust measurement test-bed. The test results are basically in consistent with the simulation results, which prove that the static characteristics analysis of the two-stage direct force control valve is accurate. The results show that when the inlet pressure remains constant, if the opening of the prestage valve flapper or the main valve spool increases. Meantime, the output flow rate of the nozzles will increase as well, and the maximum total output flowrate of the two nozzles is at the centre position. If the flapper moves from the center to the critical position, the aerodynamic force increases gradually. It is the initiative to help the flapper move, and in contrast, the opposite is true. The 644 N greater output thrust of the valve can meet the demand of the missile control system.