为了研究涡流二极管内空化现象的机理特性及对其性能的影响,我们假设流体为气液混相均质,并考虑不可凝结气相,采用基于组分输运方程,求解了涡流二极管全流道内气液混相均质流的雷诺平均N—S方程以及气相组分输运方程。数值计算结果显示了空化形成时涡流二极管入口、出口及旋流腔内的流场形态,研究表明:涡流二极管空化现象主要发生在流体切向进入时旋流腔和中心管的中心部位;空化流是由于液体在中心旋流场低压条件下汽化,同时不可凝结气体由于亨利定律在旋转流场形成的压力梯度下而发生的输运效应综合形成的;空化流由于强旋涡的原因对涡流二极管的性能产生明显的影响。上述结论对涡流二极管的设计及其指导工程应用具有重要的价值。
In order to study the cavitation performance of vortex diode, we solved the Reynolds averaged Navier-Stokes equations and phase -2 transport equations with phase of non-condensing gas. A deep study has been carried out about the occurrence, development and effect on performance of cavitation by CFD. The numerical results shows that the cavitation flow is in the centre of axial port and chamber, which is made up of the vapor caused by the low pressure in the chamber and the non-condensing gas transported to the center by the pressure drop of the swirling flow according to Dicipline of Henrry. The performance of vortex diode is deeply influenced by cavitation flow due to the forced vortex. The above-mentioned methods and results are of great guiding significance to predict the performance of vortex diode.