The Research on Optimization of the Multiphase Flow Field of Biogas Plant by Using CFD Software

Abstract

Abstract:The inner flow field of a biogas plant can be optimized by agitating the feedstock to be evenly distributed for a rising biogas production rate. A hydraulic agitator can be installed in the digester with outlets far above the bottom. Hydraulic mixing is essential in a solid-liquid two-phase flow process, in which large solid particles can be found at the initial stage and turn to being high-concentration viscous liquid (non-Newtonian fluid). A 0.75 m³ digester was taken as a case study with CFD (computational fluid dynamics) software. The basic pattern was simulated by using water as the medium and the pattern of pseudo plastic fluid state was simulated by the Euler-Euler Model, then the effect of optimized design with bottom inflow and high dispersed outlets could be verified. Viewed from the mixing effects, the velocity of 0.6 m/s is better than 1 m/s for water medium, while 1 m/s better than 0.6 m/s for pseudo plastic fluid medium.

Computational fluid dynamics (CFD) modeling and application for cleaning of food‐contact surfaces: A review

“…postulate that fluid viscosity has a negligible impact on flow conditions,Wu and Chen (2008) argue the contrary, emphasizing the distinct requirements for Newtonian and non-Newtonian fluids Huang et al (2014). noted that the consistency of the feed liquid evolves over time, with instances where solid materials eventually transition into pseudoplastic fluids.Further enriching the discourse,Li et al (2017) showcased their turbulent swirl simulations, leveraging both the RANS and LES models.…”