基于FLUENT刚性植被茎粗对坡面流特性影响研究

Analysis of Influence of Stem Diameter of Rigid Vegetation on Slope Flow Characteristics Based on Fluent Software

地表植被的地上部分主要是植被的茎部,植被的根茎能有效降低泥沙的输送能力,有助于植物的水肥管理。采用雷诺应力湍流模型,借助三维软件FLUENT,对不同根茎大小的刚性植被进行了数值研究。模拟设计了3种不同根茎大小的的植被,分别是3.5、5.0、6.5 mm,同时保持相同的植被密度,在相同流量条件下进行试验。结果表明:在淹没状态下,随着植被粗度的增加,植被间流速逐渐减小,通道处流速逐渐增加,尾旋和涡流逐步变大。植被粗度的不断增大,导致平均流速逐渐减小,与3.5 mm粗度相比,粗度为5.0和6.5 mm的平均流速分别降低了6.3%和10.6%。湍流动能和强度与植被的粗度呈正相关关系。这些结果对优化农田保护中的坡面植被分布具有重要意义。

The aboveground part of surface vegetation is mainly the stem of vegetation.The rhizome of vegetation can effectively reduce the sediment transport capacity and contribute to the water and fertilizer management of plants.In this study,U the rigid vegetation with different rhizome sizes was numerically studied by using Reynolds stress turbulence model and three-dimensional software FLUENT.Three kinds of vegetation with different rhizome sizes were simulated and designed,which were 3.5 mm,5.0 mm and 6.5 mm respectively.At the same time,the same vegetation density was maintained and the experiment was carried out under the same flow conditions.The results show that in the submerged state,with the increase of vegetation coarseness,the velocity between vegetation decreases gradually,the velocity at the channel increases gradually,and the tail vortex and vortex increase gradually.The continuous increase of vegetation coarseness leads to the gradual decrease of average velocity.Compared with 3.5 mm coarseness,the average velocity of 5.0 mm and 6.5 mm coarseness decreases by 6.3%and 10.6%respectively.Turbulence kinetic energy and intensity are positively correlated with vegetation coarseness.These results are of great significance to optimize the distribution of slope vegetation in farmland protection.