非定常尾迹输运对动叶气膜冷却流场影响

对不同尾迹宽度下涡轮动叶的气膜冷却流场进行非定常数值研究,研究了尾迹输运对动叶气膜冷却流场的影响机理.计算结果表明:非定常尾迹的总压损失和速度损失而形成低速区,当非定常尾迹输运到冷却孔附近时,尾迹对气膜层的干扰占主导地位,靠近气膜孔的叶片区域冷却效率降低明显.非定常尾迹的影响使得冷却气流被带到压力面叶片下游更广阔的区域,导致气膜冷却沿叶展方向的覆盖范围更广,从而使得压力面气膜冷却效率在尾迹通过时更高一些.当尾迹宽度增大时,对气膜冷却效率的影响程度增大.尾迹对压力面的影响比吸力面更大一些. 

Effect of unsteady wake transportation on film cooling flowfield of rotating turbine blade

Unsteady flowfield of the turbine blade with film cooling was investigated numerically under different blowing rates with the wake simulated by the cylinder rod.The effect of unsteady wake transportation on the film cooling flowfield was analyzed.Results show a zone with low velocity forms due to the total pressure defection and velocity defection.The disturbance of the unsteady dominates the formation of the cooling film when the unsteady wake is transported to the position near the cooling hole,which results in the obvious reduction of the cooling effectiveness near the cooling hole.The cooling gas can be transported to the farther downstream region due to effect of the unsteady wake,and the recovery range of the cooling gas along the spanwise direction is wider than the time without unsteady wake passing,therefore better cooling effectiveness exists on the pressure surface when the unsteady wake is transported to the position near the cooling hole on the pressure surface.The effect of the unsteady wake on the cooling effectiveness increases with the increment of the width of the unsteady wake.The effect of the unsteady wake is larger on the pressure surface than that on the suction surface.