攻角对涡轮叶片表面流动及换热的影响 *

Effects of Different Incidences on Surface Flow and Heat Transfer in Turbine Blade

关键词:  短周期风洞  非设计攻角  表面压力系数  表面换热系数

Key words:  Short-duration wind tunnel  Off-design incidence  Surface pressure coefficient  Surface heat transfer coefficient

摘要:

利用短周期跨声速换热风洞测量非设计状态下攻角对涡轮叶片表面静压及换热的影响，研究攻角对涡轮叶栅压力分布及换热系数分布的影响规律。实验结果表明，攻角变化对吸力面压力分布影响较大，正攻角时在靠近吸力面前缘处产生很大的逆压梯度，随攻角增大吸力面后部压力逐渐增高，负攻角时压力面前缘产生较小的逆压梯度；正攻角主要影响吸力面换热系数，随攻角增大吸力面前缘局部区域换热显著加强，负攻角主要影响压力面换热分布，随攻角减小压力面换热加强，大雷诺数下换热系数分布规律与小雷诺数时基本一致。

Abstract:

Surface static pressure and heat transfer are measured in different off-design incidences at short-duration transonic heat transfer wind tunnel，and the effects of incidence on surface pressure coefficient and heat transfer coefficient in turbine blade are summarized. The results suggest that incidence mainly affects the pressure distribution at suction side，near the leading-edge of suction surface a big inverse pressure gradient is produced when the incidence is positive. The pressure increases when incidence increases at the latter part of suction surface. When the incidence is negative there would be a inverse pressure gradient caused near the leading-edge of pressure surface. The positive incidence mainly affects heat transfer coefficient at suction surface. Heat transfer is strengthened at the region near the leading-edge of suction surface when the incidence increases. The negative incidence mainly affects heat transfer at pressure side，and the heat transfer is strengthened when incidence increases. The heat transfer coefficient distribution at larger reynolds number is nearly the same as that at smaller reynolds number.