应用粗糙壁面附近湍流边界层的阻力分解规律,研究了可蚀性地表上散布的颗粒状粗糙元的防风蚀效应。认为按一定密度散布在地表的颗粒状粗糙元(例如粗沙和砾石等),对抑制风蚀起到了两个关键作用:其一,增大地表盖度以减少暴露面积;其二,削弱了暴露面积上的风阻力。基于这一认识,应用量纲分析原理,建立了地表风蚀率与边界层外风速、粗糙元分布密度之间关系的理论公式,并依据有关实验数据分析了公式的可靠性。
The effects of rough granular elements on lightening wind erosion of ground were studied by considering the distribution of the friction stress exerted by the turbulent boundary layer on rough wall. It was recognized that the rough granular elements scattered on ground with a certain density (such as coarse sands, gravels, etc.) play two key roles in controlling wind erosion: increasing the ground coverage and reducing the wind friction stress on the exposed ground. Then a mathematical formula was presented by dimensional analysis, which describes dependence of the wind erosion rate on the wind speed above the boundary layer and the density of the rough elements. Finally the validity of the formula was confirmed by comparison of the calculated results with experimental data.