气、液组合膜流对壁面冷却效果的理论及试验研究

THEORETICAL AND EXPERIMENTAL STUDY ON THE COOLING EFFECT ON THE WALL OF THE COMPOSED LIQUID-GAS FILM

关键词:  薄膜冷却  气膜冷却  试验  理论  研究

Key words:  Film cooling  Gaseous film cooling  Test  Theory  Research

摘要:

本文针对液膜及气膜组合流动的特点,提出了组合薄膜流动的“四层式流场物理模型”.根据所做简化、假设,对液膜区流场结构及冷却效果进行了理论计算,并通过分析方法,对其紧接的气膜段流动及冷却效果进行了理论预估.试验的结果表明:液膜段的理论计算与试验数据基本相符.并从试验中发现了液膜蒸干后气膜段冷却的一些特点.这对研究液体冷却时液膜及气膜组合流动的冷却效果提出了可行的途径.

Abstract:

According to the flow characteristics of the composed liquid-gas film, a"four-storied" flow frame physical model is established.In the light of assumptions proposed, theoretical Calculations have been made on flow frame and cooling effect of liquid film flow section at first and theoretical estimation of cooling characteristics of the followed gas film flow section has been developed by analytical method. Under set experimental conditions, verifying experiments have been performed.The results indicae that the theoretical calculations are conformed to the experimental investigation on the whole.And the theoretical research work on the gas film section is an important effort.With it, some characteristics of the gas film cooling after liquid film vaporized-out point have been revealed.A practical way is presented for theoretical study on the cooling effect nf composed liquid-gas film flow.This paper is of certain value to the development of cooling instrument of new aero-space propulsion systems.