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一、前言 气膜冷却的基础实验研究可分为两类:稳态实验与短周期实验.稳态实验的气膜冷却效果用绝热壁面的有效温比可η_(ad)表示,η_(ad)=(T_∞—T_(aw)/(T_∞—T_2)。式中,T_∞,T_2分别为主流与射流温度,T-(aw)为绝热壁面的恢复溫度。气膜冷却绝热壁面的换热系数h_f按下式定义:q_f=h_f(T_w—T_(aw))。式中,T_w为壁温。稳态实验结果便于设计时使用,但实验参数较低。短周期实验的气膜冷却效果用等溫壁面的有效温比η_(iso)表示,η_(iso)=
I. Introduction The basic experimental study of film cooling can be divided into two types: steady-state experiment and short-period experiment.The steady-state experiment results show that the effective temperature ratio of adiabatic wall can be expressed as η_ (ad) = (T_∞ -T_ (aw) / (T_∞-T_2) where T_∞ and T_2 are the temperature of the main stream and the jet respectively, and T- (aw) is the recovery temperature of the thermal insulation wall. The thermal coefficient h_f is defined as follows: q_f = h_f (T_w-T_ (aw)) where T_w is the wall temperature and the steady-state experimental results are easy to use but have low experimental parameters. Effect with isothermal wall of the effective temperature ratio η_ (iso) that η_ (iso) =