生物搅拌槽中挡板结构对搅拌效果的影响

利用Fluent软件，对无挡板搅拌槽和有挡板搅拌槽的搅拌效果进行了对比。基于有限体积法，采用RANS（Reynolds-averaged Navier-Stokes）模型对搅拌槽中的流场进行了模拟仿真，获得了搅拌过程中湍流的流速分布、压力分布和湍动能，对流场的结构形态进行了分析。结果表明：在搅拌槽中设置的挡板宽度越大，流场内的速度值波动就越大，速度矢量变化就越大，湍动能随之变大，有利于提高搅拌槽的搅拌效果；从压力分布上看搅拌槽中的最小压力均出现在距离搅拌槽底面0.12 m处；带档板结构搅拌槽的最小压力低于不带挡板的情况；搅拌槽中的挡板会导致流场中的速度矢量具有较强的旋流效应，流场内速度梯度变化较大，形成较强的涡流，有利于搅拌过程中发生更强烈的化学反应。

Influence of a baffle structure on the stirringeffect of a biological stirred tank

Using Fluent, the difference in the stirringeffect of a biological stirred tank with and without baffle was calculated andcompared. Based on the finite volume method, the RANS（Reynolds-averaged Navier-Stokes） model wasused to simulate the flow field in the biological stirred tank, and thevelocity distribution, pressure distribution and turbulent kinetic energy inthe stirring process were obtained. The structural morphology of the flow fieldwas analyzed. The results show that the larger the baffle width, the greaterthe velocity fluctuation, the greater the velocity vector change, and thegreater the turbulent kinetic energy, which is helpful in improving thestirring effect of the biological stirred tank. According to the pressuredistribution analysis, with or without a baffle, the minimum pressure in thebiological stirred tank is 0.12 m away from the bottom of the tank. The minimumpressure with a baffle is lower than that without a baffle, The velocity vectorin the flow field of the stirred tank with baffle exhibits a stronger cycloneeffect, which could result in more intense chemical reaction occurring duringthe stirring process.