射流式旋涡发生器对涡轮流动分离控制

通过数值计算,研究了稳态小孔射流式旋涡发生器VGJs(Vortex Generator Jets)对低雷诺数涡轮流动分离的控制。通过对VGJs射流孔径、孔间距的几何参数研究,分析了射流对分离流动的控制机理。在此基础上,提出并详细研究了多种不同孔径射流孔组合排列结构对分离流动的控制效果与作用机理。研究结果表明,射流孔组合排列结构,以大孔射流为主,采用小孔小流量射流对大孔射流控制的分离流场进行"弥补"与调节,可实现总压损失进一步降低22%,射流流量减小25%。

Numerical simulation of the vortex generator jets for low-pressure turbine separation control

Detailed numerical simulations were performed to study the mechanics of VGJs in controlling the flow separation occurred on the suction side of low pressure turbine at low Reynolds numbers. The numerical simulation results show that flow loss caused by mixing loss and the separation loss can be largely reduced with VGJs. The effects of VGJs holes diameter and the holes space were investigated. Some new configurations of VGJs with combination of different diameter holes were put forward and were investigated. Because the effect of the interaction between the jet flow and the free stream is reduced, the combined VGJs could reduce the flow loss apparently with smaller jet flow mass.