管道网络算法在涡轮内冷叶片换热计算中的应用

基于管道网络算法的概念,开发了适用于内冷通道换热计算的程序,耦合外流场求解程序HIT3D,以Mark II叶片实验工况5411的结果做验证,传热系数和温度的计算值与实验值有着较好的吻合.在此基础上,对某型高压涡轮动叶内冷通道的复杂流路,建立流体网络计算模型.对原型结构吸力面一侧叶顶新增一排气膜孔,并对前部和后部蛇形通道的两组相邻通道间新增连接起平衡作用的贯通孔各3个.改型设计和原型都用开发的管道网络程序计算流动和换热参数.结果显示:在入口冷气边界条件相同条件下,相对原型,改型设计最高温度和平均温度都有10K以上的降低,叶片吸力面局部高温区集中的状况改有所善.改型设计效果在CFX全三维模拟中亦得到证实.

Application of pipeline network algorithm in turbine inner cooling blade heat transfer calculation

Based on the concept of pipeline network algorithm, the calculation procedure applicable to inner cooling channel heat exchange has been developed. Coupled with external flow field solver HIT3D, the Mark II blades condition 5411 test results were used to verify the validity of pipeline network procedure, showing that heat transfer coefficient and temperature had good agreement with the test values. On this basis, for the complex inner cooling channel flow paths of a certain type of high-pressure turbine rotor blade, a fluid network computing model was established. An exhaust film hole was added to the suction side of blade tip, and the two groups of adjacent passages of the front and rear serpentine channels were connected with three through tubes separately to balance the pressure. Retrofit design and prototype employed pipeline network procedure to calculate flow and heat transfer parameters. Results show that, under the same inlet boundary conditions of cooling air, the maximum temperature and the average temperature have decreased more than 10K as compared with prototype, and adverse conditions such as concentration of local high temperature on suction side have been improved. The improvement effect has been confirmed through full three-dimensional CFX simulation.