锥台形液压锥阀过流面积CFD可视化计算

针对液压插装阀的主阀都采用平底断面,但在计算流量时却采用按完整锥面锥阀导出的过流面积计算公式,从而造成非常大的计算误差、不能准确指导设计的问题,采用CFD流场可视化仿真对锥台形锥阀的出流特性进行了研究。通过分析阀内流场参数分布特征,判断锥阀过流断面位置,提出了转折开口度的概念。得出锥台形锥阀的阀芯在大行程范围移动时过流断面面积变化存在关键的转折点,不同行程范围不同内外流流动状况过流断面位置不同,相对应的面积计算公式也不同。采用新的面积计算公式,可以比较准确地计算锥台形锥阀的过流面积和通过阀的流量。同时,对比内外流流动状况的阀内流场特征,结合确立的过流断面,指出对于锥台形锥阀流动应考虑孔口节流损失和进出阀口局部损失的混合作用,内外流流动时进出阀口局部损失的不同是内外流流量特性不同的根源。

CFD Visual Analysis on Cross Section of Truncated Poppet Valve

It exits large computational error that the computational formula derived from the untrucated poppet valve is adopted for the cross section area of the truncated popper valve. The flow pattern of the truncated poppet valve was studied with CFD visual algorithm. The position of cross section was confirmed based on the flow filed characteristics and the concept of the turn opening position was proposed. It was concluded that the cross section area of valve had a key turning point when the stroke of truncated poppet valve was large. The established technique and computational formula of the cross section was differed from the stroke and the converging/diverging flow. The result of the cross section area and the flow rate was more exactitude by adopting the new computational formula for the truncated poppet valve than by adopting the traditional formula. Comparing the flow filed characteristics of diverging flow with that of the converging flow, it was pointed out that the channel flow in the truncated poppet valve should consider the throttling pressure loss and the local pressure loss. It was summarized that the difference of the flow filed characteristics was induced by the local pressure loss.