管道节流过程中气蚀的数值模拟

应用数值模拟的方法，对流体在圆形、六边形、正方形、渐缩及渐扩几种不同几何形状和尺寸的节流管道中流动时所产生的气蚀现象进行数值计算，模拟流体在管道节流过程中气蚀的发生过程，分析不同节流断面形状节流管道的含气量分布、沿程含气量、沿程压力变化等规律。数值计算的结果表明，在所计算的不同断面形状节流管道中，渐缩形节流管道中气蚀发生的区域最小。同时，还对具有较好气蚀特性的几种不同长度渐缩形节流管道进行模拟计算，结果显示，节流段长度对气蚀的存在区域有重要影响，随节流段长度的增加，气蚀区域向下游的发展范围逐渐加大。此外，对各种断面节流管道中气蚀产生的位置进行预测，并对气蚀形成的机理及影响因素进行分析。

Numerical Simulation on Cavitation of Throttle in Tube

The cavitation in some throttle tubes with different shapes and sizes, such as circularity, hexagon, square, covergent, divergent are calculated with numerical method. The generation process of cavitation is simulated when fluid flows through the throttle tube. The vapor content distribution, the variety of vapor content and pressure along the flow direction are analyzed. The calculation results indicate that the covergent throttle tube has the least cavitation region among the simulated throttle tubes. Meantime, the cavitation properties of several covergent throttle tubes with different length are simulated. The results show that the length of throttle section has a crucial influence on the region where the cavitation would occur. The cavitation area developed to downstream will gradually enlarge with the increase of throttle section length. Furthermore, the position where the cavitition could occur in several throttle tubes with different section is predicted. The mechanism and the influencing factors are investigated.