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以某实际燃气轮机涡轮进口导向器叶栅为研究对象,在出口为高亚声速及超声速条件下,对具有不同柯恩达表面的环量控制叶栅进行二维数值模拟,通过对比分析叶栅的气动性能和流场细节,探讨了柯恩达效应在涡轮叶栅中的作用机理.结果表明:当叶栅出口马赫数为0.60时,射流对主流有很好的携带作用,损失小于原型叶栅;叶栅出口马赫数增加到0.85时,射流仍有较强的携带主流折转的能力;当叶栅出口为超声速时,在初始阶段小曲率的柯恩达表面上,由于激波的作用,射流向流道中心折转并提前脱离壁面,初始阶段大曲率的柯恩达表面射流附壁较好,但由于叶片吸力面与射流口之间圆角的作用,射流与主流掺混不理想.
Taking a real gas turbine turbine inlet guide cascade as a research object, a two-dimensional numerical simulation of a cascade control cascade with different Coanda surfaces was carried out under the conditions of high subsonic velocity and supersonic velocity at the outlet. Aerodynamic performance and flow field, the mechanism of Coanda effect in the turbine cascade is discussed.The results show that the jet has a good carrying effect on the mainstream when the Mach number of the cascade is 0.60, and the loss is less than that of the prototype cascade ; When the Mach number of the cascade exit increases to 0.85, the jet still has a strong capability of carrying the main flow turning back. When the exit of the cascade is supersonic, on the Coanda surface with small curvature in the initial stage, due to the shock wave, The jet flow is deflected toward the center of the flow channel and departs from the wall ahead of time. The Coanda high surface jet attached to the wall at the initial stage is good, but due to the fillet between the suction surface of the jet and the jet orifice, the jet is not ideal for mixing with the mainstream.