V型调节球阀内部流场分析及空化预测

Analysis of internal flowfield of V-shaped regulating ball valve and its cavitation prediction

以某型号的V型调节球阀为研究对象,基于计算流体力学数值模拟的方法,采用Mixture混合相模型和Zwart Gerber Belamri空化模型对V型调节球阀三种不同开度下的内部流场进行分析,得到了其压力场分布和速度场分布.研究了阀内流体流动状况,并对阀内发生空化现象的区域以及空化强度进行了初步的分析和预测.分析结果表明:随着阀门开度的增大,阀内负压区后移,流速增大且阀内发生了流动分离;在V型阀口后及阀体后部靠近阀出口处发生了空化,随着开度的增大,空化强度增强.将二维与三维流道模型的数值模拟结果进行比较,定性分析时,两者可得到一致的结论;定量分析时,两者在模拟结果的数值上存在差异,三维模型更具有指导意义.

Taking a type of V-shaped regulating ball valve as an vestigation object and based on numeric simulation method of computational fluid mechanics, the internal flowfield of the ball valve with three different openings was analyzed by means of Mixture mixed-phase model and Zwart Gerber Belamri cavitation model, the distribution of pressure and velocity of the flowfield was obtained, the flow condition of the fluid inside the valve was investigated, and the cavitation occurring region and cavitation intensity in the valve were preliminarily analyzed and predicted. The analysis result showed that with the increase of valve opening, the negative pressure zone in the valve would move backward, the flow velocity would increase, and the flow separation would occur in the valve. Cavitation would occur behind valve ports and near the valve exit at the rear of the valve body and the cavitation intensity would increase as the opening increased. The results of the numerical simulation with 2-D and 3-D channel models were compared. In case of qualitative analysis, a conclusion could be obtained that both of them would be consistent. However, in case of quantitative analysis, the numeric data of them would be different, 3-D model would have more guiding value.