壅塞管空化器空化流场特性的数值模拟研究

基于水力空化相关原理和壅塞管的特性,对壅塞管空化器空化流场特性进行数值模拟研究,确认影响空化器空化效果的因素。通过研究确认,入口压力与入口直径对壅塞管空化器的空化强度有决定性影响。入口压力增大,空化器内压力梯度增大,表明入口压力越大,壅塞管空化器空化效果越好。入口直径增大,壅塞管内最大含气率升高,可在更大范围水体内产生空化泡,进而加强空化效果。在壅塞管空化器内产生比较均匀的气液混合两相流时,沿轴心线方向,从壅塞管中部位置至壅塞截面位置,气液两相流动的马赫数缓慢增大,在压力梯度到达极值时马赫数达到最大,为0.97,接近于1。

Numerical Simulation Study on Cavitation Flow Field Characteristics of Congestion Tube Cavitator

Based on the principle of hydraulic cavitation and the characteristics of the congestion tube,the numerical simulation of the characteristics of cavitation flow field of the congestion tube cavitator was carried out,and the factors affecting the cavitation effect of the cavitator were confirmed.It has been confirmed by study that the inlet pressure and the inlet diameter have a decisive influence on the cavitation intensity of the congestion tube cavitator.As the inlet pressure increases,the pressure gradient in the cavitator increases,indicating that the larger the inlet pressure,the better the cavitation effect of the congestion tube cavitator.As the diameter of the inlet increases,the maximum gas rate in the congestion tube increases and it can generate cavitation bubbles in a larger range of water substance,thereby enhancing the cavitation performance.When a relatively uniform gas liquid mixed two phase flow is generated in the congestion tube cavitator,the Mach number of the gas liquid two phase flow slowly increases from the middle position of the congestion tube to the choking plane position along the axis line.When the pressure gradient reaches the extreme value,the Mach number reaches the maximum value i.e.0.97,which is close to 1.