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湍旋流广泛存在于自然界与工程实际中,其流动特性及机械能损失的研究具有很高的理论意义与工程价值.通过开发数值旋流生成装置,采用雷诺应力模式封闭雷诺时均方程及有针对性的网格布置,实现了对圆管中湍旋流的三维精细模拟.计算成果表明:1)湍旋流的旋流数沿程呈分段指数衰减,其衰减系数有随雷诺数的增加而减小的趋势;2)湍旋流的切向时均流速沿径向的变化在旋流数较大时可近似用组合涡的速度分布来描述;3)与一般恒定均匀圆管湍流的总流机械能损失系数相比,带有旋流的圆管湍流的总流机械能损失系数要普遍大于前者,且旋流数越大,总流机械能损失系数越大.
The turbulent swirling exists widely in nature and engineering practice, and its flow characteristics and mechanical energy loss are of great theoretical significance and engineering value.Through the development of numerical cyclone generating device, the Reynolds stress mode is used to close the Reynolds averaged equation and to deal with it The results show that: 1) the swirl number of turbulent swirl flow is exponentially decayed with the exponential decay, the attenuation coefficient of which increases with the increase of Reynolds number But the tendency of decrease is the same. 2) The tangential mean velocity of turbulent swirling changes along the radial direction can be approximated by the velocity distribution of the combined vortices when the swirl number is large. 3) Compared with the general uniform turbulent Compared with the total loss factor, the total loss factor of turbulent flow in a circular tube with swirling flow is generally larger than the former, and the larger the number of swirl flows, the larger the loss factor of total flow.