超燃冲压发动机再生冷却U型通道的热传导模型研究

Heat Conduction Model in U-Shaped Regenerative Cooling Channel in Scramjet

关键词:  超燃冲压发动机  再生冷却  结构设计  温度控制  数值模拟

Key words:  Scramjet engine  Regenerative cooling  Structure design  Temperature control  Numerical simulation

摘要:

为对超燃冲压发动机再生冷却通道进行设计和改良，提出了U型冷却通道这种往返式流道的通道结构，并针对传统的同向流道和U型通道分别进行了一维程序建模，对比了两种通道的优劣。针对U型通道进行了不同高宽比对肋间传热影响的讨论和改变通道截面积以提升通道整体冷却效果的研究。研究表明：U型通道能较明显地降低燃烧室壁面的局部高温，使得整体温度分布更加均匀；适当增加高宽比，可增加肋间壁面的传热，使通道两侧温度差拉低；适当减小高宽比，可增加底壁面的传热，使局部燃烧室壁温降低。渐变通道截面积的设计方案，对解决通道出口区域燃烧室壁温过高，起到了明显的改善作用。

Abstract:

Aiming at the design and improvement of the regenerative cooling channel in a scramjet （supersonic-combustion ramjet）， a U-shaped cooling channel is proposed， which is a channel structure with reciprocating flows. And the one-dimensional program modeling is carried out for the traditional co-directional channel and U-channel respectively， and the advantages and disadvantages of the two channels are compared. The influence of different height width ratios on intercostal heat transfer of U-shaped channel is discussed， and the research on changing the cross-sectional area of channel to improve the overall cooling effect of channel is carried out. The results show that the U-shaped channel can obviously reduce the local high temperature of the combustion chamber wall， making the overall temperature distribution more uniform. Properly increasing the aspect ratio can increase the heat transfer between the ribs and reduce the temperature difference between the two sides of the channel. Reducing the aspect ratio properly can increase the heat transfer of the bottom wall and reduce the wall temperature of the local combustor. And the design scheme of gradual change channel cross-sectional area has played a significant role in solving the problem that the wall temperature of combustor in the area of channel exit is too high.