带主动冷却的超声速燃烧室传热分析

Heat transfer analysis for actively cooled supersonic combustor

关键词:  超声速燃烧室  主动冷却  传热分析  超临界态  煤油替代模型

Key words:  Supersonic combustor  Active cooling  Heat transfer analysis  Supercritical state  Kerosene surrogate

摘要:

介绍了流体、固体传热耦合的一维分析方法,对带主动冷却系统的马赫数2.5超声速燃烧室进行了传热分析。该分析以实验测量的燃烧室壁面静压以及超临界煤油换热特性数据为基础,考虑了燃气的高温离解效应,燃烧特性以及碳氢燃料的高温热物理特性,对不同燃烧状态、冷却条件下的主动冷却过程进行了分析。结果表明有燃烧时壁面热流可高达1MW/m2以上,是无燃烧时的2～3倍。当煤油流量较小时(当量比为0.45),冷却后的壁面温度仍偏高,而且冷却壁内温度分布不均匀。随着煤油流量的增加,冷却效果明显提高,冷却壁内温度分布趋于均匀;并且煤油的出口温度也显著减小。

Abstract:

A method of one-dimensional heat transfer analysis,dealing with the coupling effect of the combustion flow,coolant flow and combustor wall,has been developed for the study of an regenerative fuel cooling system for Mach 2.5 supersonic combustor.The analysis includes the air dissociation effect at high temperature,combustion characteristics of kerosene and thermophysical properties of the supercritical kerosene.Based on the measured static pressure along the combustor wall and heat transfer characteristics of supercritical kerosene,the analysis is applied to investigate the cooling process and cooling effect at different combustion and cooling conditions.The analysis shows that the wall heat flux with combustion can exceed 1 MW/m2,which is 2~3 times the value of that without combustion.Under cooling conditions with a relatively low coolant flow rate,high temperature regions and large temperature variations exist on the hot-side combustor wall.With increase in the coolant flow rate,the cooling effect is improved significantly and the fuel exit temperature decreases.