基于孔板和文丘里管复合结构空化器的空化效果数值模拟

基于计算软件Fluent,选用在低压区引入空化模型中的混合多相流模型,针对孔板和文丘里管复合空化发生器中孔板在文丘里管喉部前部、中间、后部3种结构对水力空化效果的影响进行了数值模拟计算,获得了汽含率、湍动能以及流线速度矢量分布图等数据。结果表明:文丘里管喉部夹载孔板后空化效果显著提高,而且在文丘里管后部流域中发生了二次空化;空化现象大部分发生在孔板小孔和文丘里管后部,且最高汽含率区域发生在孔板末端区域;多孔孔板置于文丘里管喉部后部时空化效果更加明显。

NUMERICAL SIMULATION OF CAVITATION EFFECT OF THE COMPOSITE CAVITATION GENERATOR BASED ON THE ORIFICE PLATE AND VENTURI TUBE

The mixture multiphase flow model had been selected in low pressure area according to the statistics calculated by large-scale computational software Fluent.The effect of different structures of the composite cavitation generator based on the orifice plate and venturi tube on hydrodynamic cavitation was simulated in a numerical calculation,and statistics of the vapor bubble fraction,turbulent kinetic energy and a flow velocity vector distribution map were obtained.Results indicated that the cavitation effect improved significantly after a orifice plate was installed at the throat of veturi tube,and a secondary cavitation happened at the rear flow area;moreover,cavitation phenomenon occurred mostly in the small holes of orifice plate as well as the rear basin of venturi tube,while the maximum vapor bubble fraction presented in the terminal region of the orifice plate;the cavitation effect was more obvious when the orifice plate was put at the rear of the venture tube throat.