中文摘要：

以往对加速效应研究中,往往只用相对简单的公式来计算山顶加速比而忽略其他复杂情况,为了讨论山体坡度、高度和地貌情况等因素的影响,利用数值模拟方法进行了山地加速效应计算,其结果显示山顶最大加速比随山体坡度和高度的增加而增大,随地面粗糙度指数的增加而减小,同时坡度、高度和地貌也对山顶加速比的空间分布有显著影响;并根据分析数据拟合了加速比计算的修正算法。

英文摘要：

In early researches on velocity speed-up effects, relative simple formulations are often used to calculate the speed-up ratio on crest, but other complex situation is neglected. In order to discuss the influence of the slope and height of hills as well as terrain conditions on speed-up effects, the speed-up ratio has been calculated by Fluent numerical simulation. The results show that the maximum speed-up ratio increases with the increasing of the slope and height of hills and with the decreasing of exponent of ground roughness. Besides, the slope, height and terrain conditions have notable influence on the distribution of the speed-up ratio on crest. Modified guidelines are suggested to correct the Original Guidelines.