瞬态液晶技术在涡轮叶片内部冷却研究中的应用

瞬态液晶测量技术能有效测量物体表面的换热系数,目前已经在传热研究中得到了广泛的应用。本文重点介绍了该测量方法在高温涡轮叶片内部冷却传热研究中的实验过程及应用。对内部冷却U型通道的传热研究表明:气膜抽吸作用下,通道内孔附近的传热得到强化,但区域平均传热系数变化不大;同时抽吸能使带肋通道中的压力损失有所降低。为了满足叶片冷却设计中对传热和压力损失的不同要求,改变弯头区的结构形式是一种有效的手段。实验结果进一步表明,瞬态液晶测量方法能准确地测量内部冷却通道中的传热分布,能为测量和优化涡轮叶片内部冷却传热特性提供可靠的数据支持。

Application of Transient Liquid Crystal on Internal Cooling Research of Gas Turbine Airfoil

As an efficient technology to measure the surface heat transfer coefficient,the transient liquid crystal(TLC) has been used in heat transfer research extensively.The application of TLC on internal cooling research of gas turbine airfoil is introduced in this paper.The research on ribbed U-duct shows that,the heat transfer near the film hole is enhanced as the effect of film extraction, but the averaged heat transfer of the wall changes little.Meanwhile,the film extraction could reduce the pressure loss of the duct.Changing the structure of turn region is an effective way to meet the requirement of heat transfer and pressure loss.All the experiments show that,the TLC could measure the heat transfer distribution on internal cooling duct effectively,and could provide reliable experimental data for design and optimization of internal cooling system.