网格密度对预测二重喷管壁面速度梯度的影响  

Effect of Grid Density on Predicting Velocity Gradient Near Walls in Double Circular Pipe

作　　者：吴迪[1] 韩凤琴[1] 黄乐平[1] 久保田乔[1] 欧清树 

机构地区：[1]华南理工大学电力学院,广东广州510640 [2]罗定水轮机厂,广东罗定527200

出　　处：《水电能源科学》2008年第4期160-162,共3页Water Resources and Power

基　　金：国家自然科学基金资助项目(50379015)

摘　　要：讨论由落差40 m到超高落差2 560 m大范围变化时冲击式水轮机二重圆管两壁面附近速度梯度变化之网格密度的影响。通过探讨壁面无因次高度找出各落差对应的最优网格密度进行数值计算,对喷管中的流动及比尺效应进行了描述。研究结果将为喷管后的流动及负比尺效应的探讨提供技术支持。The paper shows the numerical results of the velocity gradient near walls in a double circular pipe under the various grid density for the wide head range from 40 m to 2,560 m. As a result, by applying the non-dimensional grid height y^＋ from the wall as a criterion for the optimum grid density, it is possible to coherently predict the positive head-scale effect due to the velocity gradient near wall in a double circular pipe. Moreover, it is shown that the initial boundary conditions for the numerical prediction of iet interaction can be set by the method proposed.

关 键 词：冲击式水轮机 比尺效应 二重喷管 速度梯度 最优网格高度y^+ 

分 类 号：TK735[交通运输工程—轮机工程]