透平动叶前缘冲击-气膜复合冷却与旋流-气膜复合冷却的热流耦合对比研究

A Comparative Study on Conjugate Heat Transfer of Impingement-Film Composite Cooling and Swirl-Film Composite Cooling on Leading Edge of a Turbine Blade

为研究高效燃气透平叶片前缘冷却方式,针对GE-E 3高压透平第一级动叶前缘的冲击-气膜复合冷却结构进行了热流耦合数值研究,对比分析了冲击-气膜复合冷却和旋流-气膜复合冷却对动叶前缘复合冷却特性的影响。首先对5种湍流模型(标准k-ε模型、RNG k-ε模型、标准k-w模型、SST k-w模型、SST k-ωγ-Re_(θ)转捩模型)在求解冲击-气膜复合冷却时的精度进行了考核,然后对网格无关性进行了验证,在此基础上详细对比分析了冲击-气膜复合冷却和旋流-气膜复合冷却条件下透平动叶前缘的综合冷却效率、流场结构和叶片前缘材料内部温度分布,并研究了质量流量比、气膜孔展向角度对叶片前缘冲击-气膜复合冷却和旋流-气膜复合冷却综合冷却性能的影响。结果表明:在计算范围内,任意冷气质量流量比和气膜孔展向角度下旋流-气膜复合冷却结构叶片前缘两侧的整体平均综合冷却效率均比冲击-气膜复合冷却结构的整体平均综合冷却效率高6%以上;冲击-气膜复合冷却和旋流-气膜复合冷却结构的动叶前缘平均综合冷却效率均随着冷气质量流量比的增大而增大。

In order to develop high efficiency cooling method for the leading edge of gas turbine blade,a conjugate heat transfer study on the impingement-film composite cooling structure of the first stage blade leading edge of GE-E 3 gas turbine is carried out with standard k-ωturbulence model.Effects of the impingement-film composite cooling and swirl-film composite cooling on the turbine blade leading edge composite cooling characteristics are compared and analyzed.Firstly,the performance of five turbulence models(standard k-εmodel,RNG k-εmodel,standard k-w model,SST k-w model,SST k-wγ-Re_(θ)transition model)in the prediction of impingement and film composite cooling is validated with experimental data.Then the grid independence is verified.Finally,the comprehensive cooling efficiency,the flow field structure and the internal temperature distribution inside the blade leading edge materials are compared and analyzed in detail under the conditions of the two cooling schemes.And the effects of coolant to mainstream mass flow ratio and film hole spanwise angle on the combined cooling performance of blade leading edge of the impingement-film composite cooling and the swirl-film composite cooling are studied.The results show that within the scope of the study,the overall average cooling efficiency of the swirl-film composite cooling is 6%higher than that of the impingement-film composite cooling for any coolant mass flow ratio and film hole structure.In the study range,the averaged overall cooling efficiency of the leading edge for the both cooling schemes increases as the coolant mass flow ratio increases,while the temperature of the blade leading edge material decreases.