旋转条件下带出流孔的受限空间内冲击换热

Heat transfer of impingement in limited room configuration with effusion in rotating state

关键词:  旋转  涡轮叶片  薄膜冷却  冲击

Key words:  Gyration  Turbine blade  Film cooling  Impinging cooling

摘要:

以旋转涡轮叶片内部冷却为背景,在旋转条件下对带出流孔的受限空间内冲击换热特性进行了实验研究。在冲击与旋转方向、相反两种情况下,通过改变冲击雷诺数Rej(5 000~10 000)、旋转数Ro(0~0.003 4)、无因次温比(Tw-Tf)/Tw(0.056~0.134)对冲击靶面的平均换热特性进行了研究。研究发现,靶面的换热随冲击雷诺数的增加而变好;旋转对冲击换热的削弱在雷诺数较大时表现更明显;实验参数范围内浮升力对换热的影响较小;离心力、哥氏力等对换热的影响程度与内部空气的流动结构及出流方式有关。

Abstract:

With the improvement of aeroengine performance,the interior cooling efficiency of turbine blade increases more and more strictly. Exprimental investigation of internal heat transfer characteristics of impingement in limited room configuration with effusion was carried out.Impinging jets were in the direction of rotation and opposite to the rotation direction.Jet Reynolds numbers and rotation numbers and wall-to-jet temperature difference ratios were varied from 5 000 to 10 000 and 0 to 0.003 4 and 0.056 to 0.134,respectively.And rotation effect on heat transfer was obtained.The results show that the heat transfer coefficient rises with the increasing of jet Reynolds numbers.Rotation weakens heat transfer much more in condition of high Reynolds number.Buoyancy force has little effect on heat transfer in the range of experimental parameters.The effect of Coriolis and centrifugal forces on heat transfer associates close with the configuration of flow field and mode of outflow.