仿螺旋肋片通道流动换热特性的数值研究

NUMERICAL INVESTIGATION OF FLOW AND HEAT TRANSFER CHARACTERISTICS IN THE CHANNEL WITH HELIX-ALIKE FINS

运用数值计算的方法对仿螺旋肋片内冷通道内的流动特性和传热特性进行了研究,共建立五组模型,分析了入口冷气雷诺数和肋片排布方式对壁面换热和通道阻力特性的影响规律。研究结果表明:(1)随着肋片与主流方向的夹角α的增大,壁面换热增强,同时通道内平均阻力系数显著增大。(2)随着入口冷气雷诺数的增大,壁面平均努塞尔数Nu增大,平均阻力系数Eu减小。(3)改变肋片倾斜角β可使综合性能提高,且存在最佳值.在研究范围内,α=15°,β=15°时综合性能最好.

The flow and heat transfer characteristics in helix-alike internal cooling channel of the gas turbine blades were studied by numerical simulation.Five groups of models were used to predict the effect of the inlet Reynolds number and arrangement of the fins on the heat transfer and pressure drop of the passage.Results show that:(1)The heat transfer coefficients are enhanced and the average friction factor increase significantly with increasing helix-alike fin angleα.(2)The average Nusselt number increases and the average resistance coefficient decreases as the inlet cooling Reynolds number increases.(3)Changing the inclined angleβof the helix-alike fin,comprehensive performance increases. And there is an optimal performance,which is obtained under the anglesα=15°,β=15°.