扇形与平面叶栅内高负荷叶片的换热特性实验研究  

Experimental Study on Heat Transfer Characteristics of Highly-Loaded Blades Between Sector and Linear Cascade

作　　者：师晴晴 刘存良[1,2] 李洋 李维 张帆 刘海涌[1] SHI Qing-qing;LIU Cun-liang;LI Yang;LI Wei;ZHANG Fan;LIU Hai-yong(School of Power and Energy,Northwestern Polytechnical University,Xi’an 710129,China;Shaanxi Key Laboratory of Thermal Sciences in Aero-Engine System,Northwestern Polytechnical University,Xi’an 710129,China;Hunan Key Laboratory of Turbomachinery on Medium and Small Aero-Engine,AECC Hunan Aviation Powerplant Research Institute,Zhuzhou 412002,China)

机构地区：[1]西北工业大学动力与能源学院,陕西西安710129 [2]西北工业大学陕西省航空动力系统热科学重点实验室,陕西西安710129 [3]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

出　　处：《推进技术》2022年第8期277-285,共9页Journal of Propulsion Technology

基　　金：国家自然科学基金(51936008);陕西省杰出青年科学基金(2021JC-11)。

摘　　要：为了探究扇形与平面叶栅条件下高负荷叶片的外换热特性,采用瞬态液晶测量技术,测量了雷诺数(Re)、湍流强度(Tu)对扇形叶栅(曲端壁)的小展弦比高负荷涡轮叶片表面努塞尔数(Nu)的影响,并与平面叶栅(直端壁)进行了对比。结果表明,曲端壁相较于直端壁增加了21.5°的径向进气角以及上下端壁曲率不同,从而导致换热沿叶高的不对称分布。雷诺数增大,叶片各位置的换热明显增强,吸力面边界层转捩点位置不断向前缘靠近,雷诺数对直端壁的影响大于曲端壁。随湍流强度增大,努塞尔数整体有所升高,吸力面转捩点位置前移,压力面过渡现象明显增强,中弦部分努塞尔数一维特性更为明显,湍流强度对两类端壁的叶片影响类似。在研究低雷诺数或湍流强度对高负荷叶片的换热影响时,可采用直端壁进行简化,而在高雷诺数时,为了保证结果准确性,需在发动机实际扇形叶栅中进行实验。To explore the overall heat transfer characteristics of highly-loaded blades with sector cascade and linear cascade,the effects of Reynolds numbers(Re)and turbulence intensity(Tu)on the Nusselt number(Nu)of highly-loaded blades with small aspect ratio were measured by using the transient liquid crystal measure⁃ment technique with a sector cascade(curved endwall).The results were compared with those of a linear cascade(straight endwall).The results reveal the asymmetric distribution of heat transfer along the blade height of the curved endwall.That is because the radial inlet angle increases by 21.5°of curved endwall compared with straight endwall and the upper and lower endwalls have different curvature of curved endwall.With the increase of Re,the heat transfer at each position of the blade is obviously enhanced,and the transition point of the laminar boundary layer on the suction surface is approaching to the leading edge.The effects of Re on straight endwall are greater than those on curved endwall.With the increase of Tu,the overall Nusselt number(Nu)increases.The transition point on the suction surface moves forward,and the transition phenomenon on the pressure surface is obviously enhanced.The one-dimensional characteristic of Nu on the middle chord is more obvious.Tu has simi⁃lar effects on the blades of two endwalls.In the study of the influence of low Re or Tu on the heat transfer of high⁃ly-loaded blades,the straight endwall can be used for simplification.But in order to ensure the accuracy of high Re,the experiment should be carried out in the real sector cascade of the engine.

关 键 词：高负荷叶片 扇形通道 液晶 努塞尔数 雷诺数 湍流强度 

分 类 号：V231.1[航空宇航科学与技术—航空宇航推进理论与工程]