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在光滑二次流通道的基础上,分析对比了两种带肋通道(135°肋和45°肋)对气膜冷却特性的影响.采用瞬态液晶测试技术获得了气膜孔下游表面传热系数比与气膜冷却效率分布.使用Fluent软件RANS数值方法对相应结构进行了数值模拟,并使用了realizable k-ε湍流模型.光滑二次流通道模型中,气膜孔内流线呈螺旋状分布,导致较大的孔内速度分离与流动损失.冷气射流分成两部分,其中一股形成一对偏斜的对转涡.135°肋结构中,二次流通道上部分的旋转涡为顺时针方向,使得气流易于流入气膜孔,气膜孔内流线呈直线分布.45°肋结构中,二次流通道上部分旋转涡为逆时针方向,增强了气膜孔内旋转涡.45°肋结构中冷气流入气膜孔之后的流动结构与光滑二次流通道结构相似.135°肋结构气膜冷却效率最大而表面传热系数比最低.
Based on the smooth secondary flow channel, the influence of the two kinds of ribbed channels (135 ° rib and 45 ° rib) on the cooling characteristics of the gas film was analyzed and compared.The transient liquid crystal test was used to obtain the surface heat transfer Coefficient ratio and film cooling efficiency distribution.The corresponding structure was simulated by using the RANS numerical method of Fluent software and a realizable k-ε turbulence model was used.In the smooth secondary flow channel model, the flow line in the film hole was spiral Distribution, resulting in a larger hole velocity separation and flow loss.Jets of air-cooled into two parts, one of the formation of a pair of deflection of the vortex.135 rib structure, the second part of the flow channel whirlpool clockwise So that the air flow easily flows into the film hole, and the flow lines in the film hole are linearly distributed. In the 45 ° rib structure, part of the rotating vortex on the secondary flow channel is counterclockwise, enhancing the swirling vortex in the film hole. In the structure, the flow structure of the cold air flowing into the film hole is similar to that of the smooth secondary flow channel, the film cooling efficiency of the 135 ° rib structure is the maximum, and the surface heat transfer coefficient ratio is the lowest.