中文摘要：

使用雷诺应力模型（RSM）模拟横肋粗糙元地表的风场，将粗糙元横截面的高宽比 h/b、粗糙元间距宽度比w/b 以及间距高度比 w/h 作为粗糙表面的特征参数，利用数值方法定量研究了粗糙表面阻力随粗糙元密度的变化规律以及粗糙元横截面尺寸改变对阻力的影响。研究结果表明：粗糙元横截面尺寸改变不影响粗糙表面阻力随粗糙元分布密度的变化规律，粗糙元的间距高度比 w/h 是横肋粗糙表面的关键特征参数，且粗糙表面的平均总阻力在 w/h=7时取得最大值。

英文摘要：

The wind field above transverse rod-roughened surface is investigated using the Reynolds stress model （RSM）.The RSM abandons Boussinesq hypothesis that the Reynolds stress has linear relationship with mean velocity gradient.The RSM is more realistic because the convection and diffusion effects of Reynolds stress are considered.The pitch width ratio w/b 、as-pect ratio h/b and pitch height ratio w/h are regarded as the main characteristics parameters of transverse rod-roughened surface to study the effect of roughness elements distribution density and cross section size on rough surface resistance.Numerical results indicate that the mean fric-tional resistance first decreases then rises with the increasing of w/b ,while the variation of mean form resistance and mean skin resistance show contrary trends and the variation of h/b has noth-ing to do with these trends.The w/b corresponding to the maximum mean skin resistance increa-ses with h/b ,and the w/h corresponding to that keeps around 7.It suggests that the pitch height ratio is the key parameter of transverse rod-roughened surface and the maximum skin resistance occurs at w/h =7.