半封闭狭窄通道稀疏孔壁面对流换热特性
Convective heat transfer characteristics of sparse hole wall in semi-closed narrow channel
李洋 1李维 1陈竞炜 1薛树林 1杨卫华2
作者信息
- 1. 中国航发湖南动力机械研究所中小型航空发动机叶轮机械湖南省重点实验室,湖南株洲 412002
- 2. 南京航空航天大学 能源与动力学院,南京 210016
- 折叠
摘要
为了研究双层壁复合冷却涡轮叶片内部对流换热特性,设计了带侧向稀疏孔出流的窄通半封闭道,采用试验方法针对不同通道进口雷诺数和不同出流孔几何参数对出流壁面对流换热特性的影响开展了研究,结果表明:冷气的沿程出流导致在出流孔下游区域产生溢流效应与冲击效应的叠加,在出流孔下游出现典型的水滴状低温区,其覆盖面积随着出流孔径和进口雷诺数的增加而增大;出流壁面的平均努塞尔数沿流动方向呈现四种变化特征,通道进口段的平均换热努塞尔数相比通道下游区高出80％;存在一个最佳出流孔展向间距比,使得壁面的平均表面传热系数达到最大值,大展向孔间距的壁面平均努塞尔数相比中间孔间距情况低20％.
Abstract
In order to study the convective heat transfer characteristics inside the double-wall composite cooling turbine blade,a narrow semi-closed passage with lateral outflow through sparse holes was designed.Test methods were used to study the effects of different inlet Reynolds numbers and geometric parameters of outflow holes on the convective heat transfer characteristics of the outflow wall surface.The results showed that,the superposition of overflow effect and impact effect occurred in the downstream area of the outlet hole due to the outflow of cool air.A typical droplet cryogenic zone appeared in the downstream area of the outlet hole,and its coverage area increased with the increase of the outlet hole size and inlet Re number;the average Nusselt number of the outlet wall presented four variation characteristics along the flow direction.The average Nusselt number of the inlet section was 80％higher than that of the downstream section;there was an optimal outlet hole span spacing ratio,so that the average convective heat transfer coefficient on the wall reached the maximum.The average wall Nusselt number of the major hole spacing was 20％lower than that of the intermediate hole spacing.
关键词
涡轮叶片/对流换热/双层壁/侧向出流/狭窄通道Key words
turbine blade/convective heat transfer/double-wall/sparse hole wall/narrow channel引用本文复制引用
出版年
2024
NETL
NSTL
万方数据