小弯管冲击冷却结构流场和温度场的场协同分析

Field Synergy Between Flow Field and Temperature Field in Concave Wall Impingement Cooling Structure

关键词:  回流燃烧室  小弯管  冲击冷却  场协同理论  换热特性

Key words:  Reverse flow combustor  Concave wall  Impingement cooling  Field synergy theory  Heat transfer characteristics

摘要:

为研究回流燃烧室小弯管冲击冷却结构能量传递过程中对流换热的物理机制，基于场协同理论，对冲击孔径d_i、冲击孔流向间距S、冲击孔展向间距P耦合作用及冲击孔倾角α₁对小弯管冲击冷却结构换热特性的影响开展了场协同分析，并对场协同分析结果进行了试验验证。研究结果表明：协同角较小的区域主要分布在冲击腔内的流动滞止区、壁面射流区和滞止点，换热效果较好；随着S/P增大，冲击腔内平均协同角先减小后增大，在S/P为0.8时，换热效果最佳；随着S/d_i和P/d_i增大，冲击腔内平均协同角增大，换热效果减弱；随着α₁增大，冲击腔内平均协同角先增大后减小，在冲击孔垂直壁面时换热效果最佳。

Abstract:

In order to study the physical mechanism of convective heat transfer in the process of energy transfer in the impingement cooling structure of concave wall in reverse flow combustor， based on the field synergy theory， the influences of the coupling effects of the impingement hole diameter d_i， the impingement hole flow spacing S， the impingement hole spanwise spacing P and the impingement hole inclination α₁ on the heat transfer characteristics of the impingement cooling structure of concave wall were analyzed， and the results of the field synergy analysis were verified by experiments. The results show that the regions with small synergy angle are mainly distributed in the flow stagnation zone， wall jet zone and stagnation point in the impingement chamber， and the heat transfer effect is good. With the increase of S/P， the average synergy angle in the impingement chamber decreases first and then increases， and the heat transfer effect is the best when S/P is 0.8. With the increase of S/d_i and P/d_i， the average synergy angle in the impingement chamber increases， and the heat transfer effect weakens.With the increase of α₁， the average synergy angle increases first and then decreases， and the heat transfer effect is the best when the impingement hole is perpendicular to the wall.