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采用数值模拟方法对不同雷诺数下静止状态涡轮叶片前腔带气膜孔出流的冲击流动与换热特性进行了研究.分析了叶片前缘冲击流动产生的不同涡团对其内表面换热的作用机理.计算结果表明:相同雷诺数下,叶片前缘内表面气膜孔附近的换热强化比高于通道的平均值.随着雷诺数增加,换热强化比有所提高.冲击流动与通道流动耦合而形成的波浪形涡区,极大地扩展了冲击强化换热区域.气膜孔出流的抽吸作用对冲击流产生影响,进一步扩大了冷却空气在前缘内表面的覆盖范围.气膜腔叶根处纵向截面的涡团阻碍了冷气向叶根方向扩展,降低了冷却效率;而横向截面的涡团则促进冷气与壁面热气的掺混,提升了换热效果.
The numerical simulation was used to study the impinging flow and heat transfer characteristics of gas flow in the anterior chamber of the turbine blade under different Reynolds numbers. The effects of different vortices generated by impinging flow on the inner surface of the turbine were analyzed The results show that under the same Reynolds number, the enhancement ratio of the heat transfer near the gas film hole in the inner surface of the leading edge of the blade is higher than the average value of the channel. As the Reynolds number increases, the heat transfer enhancement ratio increases. The wave-shaped vortex zone coupled with the channel flow greatly expands the area of impact-enhanced heat exchange.The suction effect of the outflow of the film hole has an impact on the impinging flow, further expanding the coverage of the cooling air on the inner surface of the leading edge The eddies in the longitudinal section at the root of the gas cavity impede the expansion of the cold air toward the root of the leaf and reduce the cooling efficiency, while the cross-section of the vortex promotes the mixing of the cold air with the hot air on the wall to enhance the heat exchange effect.