【摘要】 采用k-ε模型、k-ω模型对突扩明渠流动进行数值模拟,并与实验结果进行了对比分析,同时研究了不同入口流速下突扩段的三维涡结构变化特征以及紊动强度分布规律。结果表明,RNGk-ε模型的模拟结果与实验值最为接近,能较好地反映流态,模拟突扩渠道时以RNGk-ε模型为宜。基于RNGk-ε模型,沿壁面的紊动强度最大,距离壁面越远紊动强度越小,最后趋于恒定;随着突扩的产生,壁面紊动强度减小,垂向紊动强度有所增大。来流速度增加时,突扩处形成的涡结构逐渐增大,回流区逐渐拉长。更多还原

【Abstract】 k-εturbulence model and k-ωturbulence model were used to simulate the flow in sudden-expansion open channel whose fitted results were compared with experimental data;At the same time,the change characteristics of 3-D vortex structure and turbulence intensity in sudden-expansion sections were studied under different inlet velocities.The results showed that RNGk-εturbulence model agreed well with experimental data and could reflect the true flow.Based on RNGk εturbulence model,turbulence intensity along the wall surface was the top,it became small and tended to be stable with the increase of distance from wall surface.With the sudden-expansion happening,turbulence intensity of wall surface weakened and vertical turbulence intensity was improved.The vortex structure in sudden-expansion section became bigger and recirculation zone lengthened gradually.RNGk-εturbulence model could fit the flow in suddenexpansion open channel.更多还原