湿地刚性植物对水流结构影响的三维数值模拟

Three Dimensional Numerical Simulation of Flow Structure Effect of Wetland Rigid Plant Growth

针对有植被的湿地水流问题的复杂性,基于VOF表面跟踪技术下的RNGk-ε模型,采用有限体积法和PISO算法建立了数值模拟方法,通过对同一来流情况下三种不同株径的刚性植物群的数值计算,分析了植物带前、带中、带后典型断面的纵、横向水面线变化及流场。结果表明,随植物的生长,不同断面水流的水位、平均流速与植物的株径均有密切关系,利用模型计算的结果与实验值吻合较好,该方法用于模拟湿地刚性植物对水流的作用行之有效。

Aiming at complexity of wetland flow problem with plant cover, numerical simulation method is established in terms of finite volume method and PISO algorithm based on the RNG k-ε model with VOF surface tracing technique. The changes of horizontal and vertical water surface profile and flow field of typical section of plant zone are analyzed by using numerical calculation of rigid plant formation with three kinds of different plant diameter for the same inflow. The results show that the water level and the average velocity of different section relate to the plant diameter with the plant growth. Results obtained by calculation model coincide with the experimental results. The proposed method can be used to simulate wetland grid plant impact on the flow effectively.