弯道导流墙对氧化沟水力特性影响的数值模拟
Numerical simulation of the influence of bend guide wall on hydraulic characteristics of oxidation ditch

【目的】对两沟道氧化沟内水下推动器、曝气转盘同时运行时，增设弯道导流墙后沟内的流场及流速分布进行研究,以期提高沟内水流混合能力并降低能耗。【方法】在试验模型右侧增设弯道导流墙，并采用数值计算的方法求解气 液两相流时均方程，紊流模型采用RNG 模型，自由水面捕捉采用VOF(Volume of fluid)法，速度与压力耦合方程组求解时使用SIMPLE(Semi-Implicit Method for Pressure-Linked Equations)算法，对氧化沟内的流场及流速分布进行模拟研究。【结果】数值模拟表明，在水下推动器、曝气转盘同时运行时增设弯道导流墙后,氧化沟内的流场及流速分布更加均匀，整个氧化沟内流速大于0.3 m/s的流体体积百分比由不增设弯道导流墙时的40.8%提高至47.6%，显著提高了氧化沟内的流速。【结论】水下推动器、曝气转盘同时运行时，增设弯道导流墙能够明显改善氧化沟内流场及流速的分布，可以提高沟内整体流速，防止或减少沟内污泥沉积。
【Objective】The flow field and velocity distribution after adding guide wall in two channel oxidation ditch with submersible propellers and disk aerator running simultaneously were investigated to improve the flow mixture ability and reduce energy consumption.【Method】Guide wall was added in the test model on the right side and the gas-liquid two-phase flow equation was solved by numerical simulation.The RNG model was used and the VOF (Volume of fluid) method was applied to track the flow surface.Velocity and pressure coupling equation was solved by the SIMPLE(Semi-Implicit Method for Pressure-Linked Equations)algorithm to simulate the flow field and velocity distribution of the oxidation ditch.【Result】Adding guiding wall in the two channel oxidation ditch with submersible propellers and disk aerator running simultaneously made the flow field and velocity distribution more uniform.The velocity greater than 0.3 m/s after adding guiding wall in the whole oxidation ditch increased from 40.8% to 47.6%.【Conclusion】The guide wall not only improved the distribution of flow field and velocity but also improved the velocity of the whole oxidation ditch and reduced the sludge deposit in oxidation ditch with submersible propellers and disk aerator running simultaneously