基于CFD的斜三通管水力特性分析及流场计算

为探究不同出口夹角下的斜直三通管水力特性,揭示水流所受重力作用下不同入口雷诺数、斜直三通管主管与支管间夹角、局部水头损失系数三者之间相关关系,阐明斜直三通管内部流场分布情况.采用Solidworks 2016对不同夹角斜三通管建立物理模型,利用Ansys 18.0软件进行网格划分与数值计算,运用Tecplot软件进行后处理.结果表明:ζ₁₃,ζ₁₂均随着雷诺数的增加呈现降低趋势,且在雷诺数大于127 616之后呈现缓慢降低趋势;ζ₁₃随着三通管夹角的增加呈现增大趋势,ζ₁₂随着三通管夹角的增大呈现降低趋势;在相同雷诺数下,压力云图在夹角小于90°时分布较为均匀,夹角大于90°时开始出现低压区;速度云图和流线图均随着夹角的增大呈现紊乱和不规则分布;湍流强度随着夹角的增大呈现增大趋势.在实际生产应用中应尽量减少三通管夹角的大小以减少能量损失,提高过流能力.

Hydraulic characteristics analysis and flow field calculation of inclined tee pipes based on CFD

The flow field in inclined straight tee pipes under the action of gravity was simulated by using ANSYS Fluent 18.0 to explore the hydraulic characteristics of the pipes at different inclination angles, and reveal the correlation among inlet Reynolds number, inclination angle between main pipe and branch pipe and minor head loss coefficient. The physical models of the tee pipes with different inclination angles were established in Solidworks 2016, the mesh in the fluid domain was generated by ANSYS 18.0 meshing module, and the flow visualization was done in Tecplot software. The results showed that ζ₁ and ζ₁₂ are increased with increasing Reynolds number, but after the Reynolds number is larger than 127616, they decrease slowly. ζ₁₃ shows an increasing tendencyf, but ζ₁₂ exhibits the tendency of decrease with increasing tee inclination angle. At the same Reynolds number, when the inclination is less than 90°, the pressure is more evenly distributed, when the angle is greater than 90°, however, a low-pressure zone starts to appear. The velocity contours and streamlines were disordered and present irregular patterns with increasing inclination angle. The turbulence intensity increases with increasing inclination angle. In practical production and application, the inclination angle of inclined straight tee pipes should be designed as small as possible to reduce energy loss and improve flow capacity.