摘要
燃气轮机涡轮叶片真实壁面与燃气温比实验存在耗费高、测量误差大的问题。采用数值模拟可以避免高温实验带来的困难。运用Fluent商业软件数值模拟叶栅进出口压比为2,壁面与燃气温比T_R分别为0.7、0.8和0.9时,叶片吸力面和压力面的努塞尔数及速度分布。结果表明:T_R越大,壁面附近无量纲温度梯度越小,叶片表面努塞尔数越小;T_R为0.9与0.7时,努塞尔数相差最大达32%;随着T_R的增大,吸力面分离泡产生的位置向前缘靠近,分离泡沿流向和法向的范围增大;由于分离泡引起湍流边界层的分离与再附,叶片表面的努塞尔数沿主流方向在0.836<x/d<0.884范围内急剧上升。本文研究结果可为燃气轮机真实壁面与燃气温比下的设计修正提供理论依据。
Experiments on temperature ratio of the actual wall surface to gas of the gas turbine blades have the problems of high cost and large measurement error. Using numerical simulation can avoid the difficulties caused by high-temperature experiments. In this study, the Nusselt number and velocity distribution on the suction and pressure surfaces of the blades are studied by numerical simulation using the Fluent commercial software when the inlet and outlet pressure ratio of the cascade is 2 and the wall-to-gas temperature ratio（T_R） is 0.7, 0.8 and 0.9,respectively. The results show that the larger the temperature ratio T_R is, the smaller the dimensionless temperature gradient near the wall and the Nusselt number on the blade surface are. The maximum difference of the Nusselt number is up to 32% between the temperature ratio T_R of 0.7 and 0.9. With the increase of the temperature ratio T_R, the position of the separation bubble on the suction surface is closer to the leading edge and the range of the separation bubble along the flow direction and the normal direction is increased. The Nusselt number of the blade surface rises sharply in the main direction in the range from x/d=0.836 to x/d=0.884, due to the separation and reattachment of the turbulent boundary layer caused by the separation bubble. The results in this study can provide a theoretical basis for the design modification of actual wall-to-gas temperature ratio of the gas turbine.
作者
李广超
窦翔宇
张魏
寇志海
LI Guangchao;D;ZHANG Wei;KOU Zhihai(Faculty of Aerospace Engineering,Shenyang Aerospace University,Shenyang 110136,China)
出处
《热力发电》
CAS
北大核心
2018年第8期44-49,共6页
Thermal Power Generation
基金
国家自然科学基金项目(51406124)
辽宁省自然科学基金项目(201602576)~~
关键词
壁面与燃气温比
努塞尔数
无量纲温度
激波
边界层
分离泡
wall-to-gas temperature ratio
Nusselt number
dimensionless temperature
shock wave
boundary layer
separation bubble
