不同雷诺数下90_弯管内流动特性的数值研究.pdf

上海理工大学学报 32 6 J. University of Shanghai for Science and Technology Vol. 32 No. 6 2010 : 1007- 6735(2010)06- 0525- 05 90 孙业志, 胡寿根, 赵 军, 仲志刚 ( , 200093) : 运用FLUENT 软件中的RNG k- 模型对不同R e 下圆形 面90弯管内空气流动进行了 模拟,分析了管内压力分布二次流动和壁面上压力系数的变化, 研究了Re 不同时对壁面压力系 数的影响. 发现在气流进入弯管段后, 流场由于流体惯性和分子黏性的相互作用, 各 个 面上出现 了对称的二次流涡对. 随Re 增大, 流体对于管道壁面的压力增大, 管内压力损失也在增大. 管道壁 面上的压力系数随R e 的不同差别不大, R e 越大, 压力系数越小, 并且管道外壁面变化比内壁面更 加明显. 湍流时压力系数沿程变化比层流明显很多, 曲率的影响也要强于层流. : 90弯管; RNG k- 模型; 二次流; 压力系数 : O 359 : A Numerical study on flow characteristics of 90bend i e under different reynolds number SUN Yezhi, HU Shougen, ZHAOJun, ZHONG Zhigang (Collegeof Energy and Power Engineering, University of Shanghai for Science and Technology , Shanghai 200093, China) Abstract: The flow under different Re number in 90 bend pipe was simulated numerically by the RNG k- turbulent model in software F UENT, andthe pressure distribution inside the tube, the secondary flow and the change of wall pressure coefficient were analyzed. The affect of low Re number on the flow structure and characteristics was investigated emphatically. It is found that the secondary flow occurs at the pipe section of the flow due to fluid inertia and molecular viscosity. With increasing Re number, the fluidpressureon the pipe wall andthe pressure loss increase. Pres sure coefficient on the pipe wall will appear in a few difference under different Re number. When Re number is greater, the pressure coefficient will be smaller, and on the pipe outer wall change more obviously than on the inner wall surface. When the flow is turbulent, the pressure coefficient along flow changes more significantly than when it is laminar flow, and the cur