Wu Binxin, Chen Shulin
Department of Biological Systems Engineering, Washington State University, Pullman, Washington 99164, USA.
Biotechnol Bioeng. 2008 Feb 15;99(3):700-11. doi: 10.1002/bit.21613.
A general mathematical model that predicts the flow fields in a mixed-flow anaerobic digester was developed. In this model, the liquid manure was assumed to be a non-Newtonian fluid, and the flow governed by the continuity, momentum, and k-epsilon standard turbulence equations, and non-Newtonian power law model. The commercial computational fluid dynamics (CFD) software, Fluent, was applied to simulate the flow fields of lab-scale, scale-up, and pilot-scale anaerobic digesters. The simulation results were validated against the experimental data from literature. The flow patterns were qualitatively compared for Newtonian and non-Newtonian fluids flow in a lab-scale digester. Numerical simulations were performed to predict the flow fields in scale-up and pilot-scale anaerobic digesters with different water pump power inputs and different total solid concentration (TS) in the liquid manure. The optimal power inputs were determined for the pilot-scale anaerobic digester. Some measures for reducing dead and low velocity zones were proposed based upon the CFD simulation results.
建立了一个预测混合流厌氧消化器内流场的通用数学模型。在该模型中，假定液体粪便为非牛顿流体，其流动由连续性方程、动量方程、k-ε标准湍流方程以及非牛顿幂律模型控制。应用商业计算流体动力学（CFD）软件Fluent对实验室规模、放大规模和中试规模的厌氧消化器内的流场进行模拟。模拟结果与文献中的实验数据进行了验证。对实验室规模消化器内牛顿流体和非牛顿流体的流动模式进行了定性比较。进行了数值模拟，以预测不同水泵功率输入和液体粪便中不同总固体浓度（TS）的放大规模和中试规模厌氧消化器内的流场。确定了中试规模厌氧消化器的最佳功率输入。基于CFD模拟结果提出了一些减少死区和低速区的措施。
