CFD simulation of non-Newtonian fluid flow in anaerobic digesters.
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.
Wu
Binxin
B
Department of Biological Systems Engineering, Washington State University, Pullman, Washington 99164, USA.
Chen
Shulin
S
D019149:Bioreactors; D003198:Computer Simulation; D008372:Manure / Q000382:microbiology*; D008962:Models, Theoretical; D012212:Rheology / Q000379:methods*
D008372:Manure