论文部分内容阅读
运用FLUENT软件中的RNGk-ε模型对不同Re下圆形截面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,各个截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Re的不同差别不大,Re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.
The RNGk-ε model in FLUENT was used to simulate the air flow in a 90 ° circular duct with different Re Reynolds numbers. The pressure distribution in the pipe, the secondary flow and the pressure coefficient on the wall were analyzed. It is found that the symmetry of secondary flow vortex pairs occurs in all cross sections due to the interaction of fluid inertia and molecular viscosity after the flow enters the bend section, Of the pressure increases, the pressure loss in the pipe is also increasing.The pressure coefficient on the wall of the pipe is not significantly different with Re, the larger the Re is, the smaller the pressure coefficient is, and the change of the outer wall of the pipe is more obvious than the inner wall. The variation along the course is much larger than that of the laminar flow, and the influence of the curvature is also stronger than that of the laminar flow.