水压锥阀空化射流流场结构与流量特性的相关性研究

为了研究水压锥阀空化流场与流量特性的相关性,对两种阀座结构的水压锥阀内部的空化射流开展了三维动态流场仿真.结果表明,直角型锥阀和倒角型锥阀均在阀芯后沿存在分离流诱发的附着型空化,在阀口下游有漩涡空化;此外,倒角阀座流道内亦存在分离流现象并形成附着型空化.倒角型流道入口处的分离流造成流体的局部加速,对于0.6 mm开口度...

Study on correlation between cavitation jet field structure through water poppet valve and flow characteristics

In order to study the correlation between cavitation jet field through the water poppet valve and flow characteristics，3D dynamic flow field was simulated for cavitation jet in the water poppet valves of 2 different valve seat structures.The results show that both sharp poppet valve and chamfered poppet valve exhibit attached cavitation at poppet trailing edge due to flow separation，and vortex cavitation between the orifice outlet and poppet trailing edge.Additionally，the flow separation also occurs at the inlet of the chamfered groove，contributing to attached cavitation within the groove.The flow separation within the chamfered groove leads to local acceleration of the fluid.The velocity at the center of the jet of the chamfered poppet valve under non-cavitation flow is 30% higher than that in sharp valve seat for 0.6 mm openness，and the flow discharge coefficient for the sharp and chamfered valve seat case is 1.02 and 0.7，respectively，showing that the flow discharge coefficient is related to the velocity value of the jet center.Under cavitation flow condition，the cavitation region is located downstream of the orifice in sharp poppet valve，the shearing strength of the jet is enhanced，making the effective flow area larger，and the flow discharge coefficient remains almost constant.The attached cavitation within the chamfered groove poses an extra throttling effect on the jet flow inside the chamfered poppet valve，and thus the flow discharge coefficient gradually reduces.