非全周开口滑阀运动过程液动力数值计算

Transient simulation on flow force of non-circular opening spool valve

为了获取非全周开口滑阀运动过程液动力特性,以油液流出U形节流槽方向为例,采用非一致性、滑移网格技术及UDF编程方法,研究阀芯运动速度、运动方向、进出口压差及节流槽个数对阀芯所受液动力的影响规律.研究结果表明,在阀芯运动速度低于0.1m/s,阀芯运动时所受的液动力与阀口开度一定稳态计算时的液动力相差不大,可以用瞬态计算近似稳态计算;阀芯运动速度越高,阀芯所受液动力与稳态计算时液动力偏离越大;当阀芯运动方向改变时,液动力出现滞环,速度越大,滞环越大且在小开口下出现液动力方向变化;进出口压差越大,节流槽个数越多,阀芯所受液动力增大,滞环越明显.

The oil outflow condition in the spool valve with U shaped notches was analyzed as an example in order to obtain the flow forces characteristics of the non-circular opening spool valve in spool movement process under such conditions as different spool speed,direction of movement,pressure differential and throttle slot numbers.The non-conformal,sliding mesh techniques and UDF programming method were adopted.Numerical results show that there is only marginal difference between the flow forces obtained from steady and transient calculations when the spool speed is below 0.1m/s,so transient calculation can be approximately used in place of steady state calculation.The deviation between these two simulation results became more obvious with the increase of spool speed.The flow force hysteresis appeared when the spool motion direction changed.Flow force redirection happened when the spool approaching to small valve opening with big speed in closing movement.The hysteresis became more obvious with the addition of spool speed,pressure differential and throttling groove number.