旋风分离器分离空间流场的理论分析

针对旋风分离器内流场特点，运用代数涡粘模式，给出了描述分离器内流体运动的简化方程。用假设轴向或径向速度分布函数形式的方法，求得了与测量结果较为一致的三维速度半理论解。边壁速度和内外旋流分界面化置分别用入口收缩系数和最小压降原理确定。分析了湍流特征尺度——普朗特混合长度和柯莫格罗夫尺度的分布规律。结果表明，湍流特征尺度的理论计算结果与实验结果吻合较好。

Theoretical analysis on internal flow field of separation space in cyclone separators

A set of simplified gas motion equations for the internal flow in a cyclone separator was established with the algebraic eddy viscosity model. A semi-empirical three-dimensional velocity solution to the simplified equations for the separation space was deduced using the assumed axial or radial velocity profile. The solution agrees fairly well with the measured velocity distributions. The wall tangential velocity and the radius of the dividing surface between the quasi-free and quasi-forced vortex flow, which were the two key variables in the solution, were determined using the theory of inlet jet contraction and the principle of minimum pressure drop respectively. Hosed on the semi-empirical solution, the distributions of the characteristie length scale of turbulence, i.e. , the Prandtl mixing length and the Kolmogorov scale, were analyzed. The predicted distributions of the above two scales in cyclones were also in good agreement with the measured ones.