摘要
采用求解三维Reynolds-Averaged Navier-Stokes(RANS)和标准k-w紊流模型的方法数值研究了端壁与动叶相对运动时动叶顶部的气动换热特性。以实验测量的叶栅为研究对象验证了所采用的数值方法和紊流模型的有效性。分析了端壁与叶顶有无相对运动时叶顶间隙高度对动叶顶部气动换热特性的影响。研究结果表明:端壁与叶顶存在相对运动时,叶顶换热系数随着间隙高度的增大而增大。在小叶顶间隙(s=0.2%H)时叶顶表面平均换热系数最小,动叶顶部前缘处的换热系数显著降低且泄漏流方向发生较大偏转。同时近顶部的吸力面侧前缘换热系数较大,随着叶顶间隙高度增大该区域的换热系数降低。端壁与叶顶无相对运动时,随着叶顶间隙高度的增加叶顶换热系数先增大后减小且在叶顶间隙中间弦长处产生大范围流动分离,当s=0.5%H时叶顶平均换热系数最大。小叶顶间隙(s=0.2%H)时端壁与叶顶存在相对运动时,动叶气动效率比端壁与叶顶无相对运动提高0.5%。大叶顶间隙(s=2.0%H)时端壁与叶顶无相对运动时,动叶气动效率比端壁与叶顶存在相对运动提高0.29%。
Numerical investigations on the aerothermal characteristics of the turbine blade tip was conducted by using the three - dimensional Reynolds-Averaged Navier-Stokes （RANS） and standard k-w turbulent model based on ANSYS-CFX. The accuracy of the utilized numerical method was validated by comparison of the experimental data. The effect of the tip clearance on the aerothemal characteristics of the turbine blade tip with and without consideration of the endwall relative motion was analyzed. The numerical results show that for RCM mode, the heat transfer coefficient on blade tip is enhanced with the increase of tip clearance. For the case with s = 0. 2% H ,the heat transfer coefficient on blade tip near the leading edge is reduced significantly, and the direction of the leakage flow in this region is obviously changed. In addition, the heat transfer is weakened on the suction side surface near the leading edge with the increase of tip clearance. For RCM mode, the case with s =0.5% H obtains the maximum heat transfer coefficient on blade t ip , and the significant separation is observed near the middle chord in the tip gap for the cases with 5 = 1. 0%H and s =2. 0%H. For a small tip clearance （5=0. 2% H） , the aerodynamics efficiency of RCM mode is 0. 5% higher than NRCM mode. Nevertheless, the aerodynamics efficiency of NRCM mode is 0. 29% higher than RCM mode for the large tip clearance s - 2. 0%H.
出处
《燃气轮机技术》
2017年第2期11-16,57,共7页
Gas Turbine Technology
基金
国家自然科学基金资助项目(51376144)
关键词
叶顶换热
端壁相对运动
叶顶泄漏
数值模拟
blade t ip
casing relative motion
tip leakage
numerical simulation
作者简介
杜昆（1990-）,男,陕西人,博士研究生,主要研究方向是叶轮机械气动热力学与传热冷却技术;
通信作者：李军,男,教授,博士生导师,E-Mail：junli@mail.xjtu.edu.cn.
