涡轮叶片波纹内冷通道流动传热机理研究

Investigation on flow and heat transfer mechanism of corrugated internal cooling channel of turbine cascades

针对叶片强化冷却散热的关键科学问题,提出并设计了新型波纹通道冷却结构,开展了精细化数值模拟,分析冷气进口雷诺数和波纹形状参数对其传热性能的影响,研究了高雷诺数涡轮叶片波纹通道冷却结构的流动传热机理。计算结果表明:波纹通道波峰波谷的交替出现对流场有强烈扰动效果,局部表面传热系数可达光滑通道的2~3倍;同一波纹不同位置传热效果不同,在管道收缩处表面传热系数最大;波纹通道传热能力与波纹形状密切相关,在冷气进口雷诺数较大时于H/L=0.115附近传热效果最佳。论文揭示了波纹通道强化传热的物理机制,为航空发动机叶片冷却结构设计提供技术支撑。

A new type of corrugated channel cooling structure was proposed and designed for the key scientific problem of strengthening the cooling and heat dissipation of cascades.A refined numerical simulation was carried out to analyze the effect of the cold air inlet Reynolds number and corrugated shape parameters on the heat transfer performance,and the flow and heat transfer mechanism of the corrugated channel cooling structure of the high Reynolds number turbine blade was studied.The calculation results showed that the alternating peaks and troughs of the corrugated channels had a strong perturbation effect on the flow field,and the local heat transfer coefficient was 2—3 times stronger than the smooth channels;the heat transfer effect varied with positions on the same corrugation,and the heat transfer coefficient was the largest at the contraction of the channel;the heat transfer capacity of the corrugated channel was closely related to the shape of the corrugation,and the heat transfer effect was the best near H/L=0.115when the Reynolds number of cold air inlet was large.The physical mechanism of the corrugated channel to enhance heat transfer was revealed,providing a technical support for the design of the cooling structure of aero-engine cascades.