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针对跨声速平面叶栅中气膜冷却对流场的影响,采用数值模拟的方法,分析了激波和边界层的相互作用及引入气膜冷却之后三者之间的影响。结果表明,由于激波形成的逆压力梯度导致边界层出现分离现象,在引入冷却射流以后被部分抑制,流场细节显示在原分离处新形成了两个方向相反的分离旋涡。保持冷却条件不变,随着孔间距的减小,边界层分离现象被抑制的效果更加明显,平面叶栅热力损失系数逐渐减小。当孔径和孔间距之比达到0.67时,相对于没有引入气膜冷却的情况,热力损失系数降低了13%。冷气流量对射流和主流相互作用流场影响显著,冷气出口局部超声速区域显著增大流场损失,降低冷却效果。
Aiming at the influence of film cooling on the flow field in transonic cascade, numerical simulation is used to analyze the interaction between the shock wave and the boundary layer and the influence of gas film cooling on the flow field. The results show that the separation of the boundary layer caused by the inverse pressure gradient of the shock wave is partially suppressed after the cooling jet is introduced. The details of the flow field show that two separate vortices with opposite directions are newly formed at the original separation. With keeping the cooling conditions unchanged, with the decrease of the hole spacing, the boundary layer separation phenomenon is more obvious, and the thermal loss coefficient of the plane cascade decreases gradually. When the ratio of aperture to hole pitch reaches 0.67, the coefficient of thermal loss is reduced by 13% relative to the case without film cooling. The influence of cold air flow on jet flow and mainstream interaction flow field is remarkable, and the local supersonic flow field at air outlet significantly increases the loss of flow field and reduces the cooling effect.