倾斜冲击与柱肋组合冷却结构的传热特性

Heat Transfer Characteristics of Inclined Impingement and Pin-Fin Cooling Structure

燃气轮机透平叶片尾缘部分空间狭小,阵列冲击等强化换热结构难以直接应用。而倾斜冲击与柱肋扰流是两种易于在狭窄空间布置的冷却结构。本文针对倾斜冲击与柱肋组合冷却结构的传热特性开展了数值研究,以冲击孔倾斜角度及开孔率为研究变量。结果显示,提升倾斜角度对于换热能力的提升效果有限,且换热强度呈现出不规则变化。随着倾斜角度的提升,倾斜冲击与柱肋组合冷却结构的换热机制由柱肋前缘的马蹄涡向冲击强化转变。扩大冲击孔的开孔率会降低换热强度,同时显著降低压力损失。

The space of gas turbine blade trailing edge is limited. Complicated heat transfer methods, such as impingement array cannot be applied to trailing edge directly. Inclined impingement and pin-fin are two cooling structures which can be easily arranged in tight spaces. In this paper,a numerical study is conducted on the heat transfer characteristics of inclined impingement and pin-fin cooling structures. Inclined angle and opening ratio of impingement holes are the research variables. The results show that the increase of inclined angle has a limited promotion on the heat transfer capacity. And the heat transfer capacity presents an irregular variation. With the increase of the inclination angle, the heat transfer mechanism converts from horseshoe vortex to impingement.Expanding the hole-opening rate of the impingement hole reduces the heat transfer strength while significantly reduces the pressure loss.