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为研究主流逆压力梯度下气膜孔的几何结构和气动参数对流量系数的影响规律,采用放大模型在低速回流式风洞中进行了实验。在对比研究圆柱孔和双向扩张孔流量系数基础上,重点研究了双向扩张孔的流量系数。结果表明,双向扩张孔的流量系数比圆柱孔的流量系数高。前倾角越大,流量系数越高;径向角越大,流量系数越高。流量系数随动量比的增加而增高,在动量比小于4时增幅尤其明显。主流湍流度增大使流量系数增大,动量比越小,增幅越大。除了在孔轴线与平板的夹角较大情况外,密度比对流量系数的影响较小。
In order to study the influence of the geometrical structure of the film hole and the aerodynamic parameters on the flow coefficient under the mainstream reverse pressure gradient, experiments were carried out in the low speed return flow wind tunnel by using the enlarged model. Based on the comparison of the flow coefficient of cylindrical hole and bidirectional expansion hole, the flow coefficient of bidirectional expansion hole is mainly studied. The results show that the flow coefficient of the bidirectional expansion hole is higher than the flow coefficient of the cylindrical hole. The greater the anteversion, the higher the flow coefficient; the greater the radial angle, the higher the flow coefficient. The flow coefficient increases with the increase of momentum ratio, especially when the momentum ratio is less than 4. Mainstream turbulence increases the flow coefficient increases, the momentum ratio is smaller, the greater the increase. In addition to the hole axis and the larger angle between the plate, the density ratio of the flow coefficient less affected.