冲击加多斜孔双层壁冷却方式气膜绝热温比研究

采用传热传质类比方法,对冲击加多斜孔双层壁冷却方式气膜绝热温比进行了实验研究.主要考虑了双层壁夹缝高度、冲击壁、吹风比、孔排列方式、以及孔间距对局部绝热温比的影响.并且给出了根据5种几何结构实验板的展向平均绝热温比沿流向的分布运用最小二乘法拟合公式.研究结果表明:对某一确定几何结构的多斜孔实验板,加冲击壁与否以及双层壁间夹缝高度的变化对相同吹风比下的绝热温比影响甚小,局部绝热温比的分布主要取决于吹风比和孔阵排列方式.从绝热温比考虑,叉排长菱形排布比较理想.

The Adiabatic Film Effectiveness of the Double Wall with Inclined Multihole and Discrete-hole for Combustor Liner

The adiabatic wall film cooling effectiveness of double wall with impingement of cooling air through discrete-hole wall to the inclined multihole wall were investigated experimentally,on the basis of the heat-mass transfer analogy.The mass transfer measurements were conducted for film cooling mass flow ratios ranging from 0.5 to 2.0,different hole pitch-to-diameter ratios,and the spacing of double wall.Finally,the formulas for five different structures of double wall were fitted by the least square method according to the distribution of average lateral adiabatic wall film cooling effectiveness.The results of the investigation show that the adiabatic wall film cooling effectiveness is affected very little by the distance between the double wall for the same blowing ratio and the same geometry of the inclined multihole wall.But its distribution is determined mainly by the blowing ratio and the hole arrangement of the inclined multihole wall.The long rhombus hole arrangement of the inclined multihole wall is a better way in view of the adiabatic wall film cooling effectiveness.