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本文得出了边界层中近底的层流区,过渡区和对数区的连续流速分布,适用于光滑表面、粗糙表面和减阻流体。这一结果是根据均匀流运动方程和边界层紊流区涡流粘滞度按抛物线分布导出的。用改变涡流粘滞度朝向流动边界的分布来考虑所增加的糙度影响。最后得到的流速分布与已发表的资料相符,並且比粗糙表面流速的经典对数分布结果更好,在给定用以计量离边界距离的座标原点处,流速下限为零。这种分布函数在边界层外区接近对数表达式,並且有一个优点,即在边界层的顶部流速分布的予报坡度为零。尽管涡流扩散系数的抛物线分布没有考虑具有尾流分量的流速分布影响,但是提出了另外考虑这些影响的涡流扩散系数分布。
In this paper, the continuous velocity distribution in the laminar, transitional and logarithmic zones of the boundary layer is obtained, which is suitable for smooth surface, rough surface and drag reducing fluid. This result is derived from a parabolic distribution based on the uniform flow equation of motion and the vortex viscosity in the turbulent boundary zone. The added roughness effect is taken into account by changing the distribution of eddy viscosity towards the flow boundary. The resulting flow velocity profile is consistent with published data and is better than the classical logarithmic distribution of the surface velocity of the rough surface, with a lower flow limit of zero given the coordinate origin used to measure the distance from the boundary. This distribution function approaches the logarithmic expression in the outer boundary layer and has the advantage that the slope of the flow velocity profile at the top of the boundary layer is zero. Although the parabolic distribution of the eddy current diffusion coefficient does not consider the influence of the flow velocity distribution with wake components, the eddy diffusion coefficient distribution considering these influences is proposed.