Smoothed particles hydrodynamics simulations of microbial kinetic in a stirred bioreactor with proximity impellers

Stirred bioreactors are very important in several industrial bioprocesses, resulting in the production of biomass and value-added products. Hence, there is a recognized need to evaluate the hydrodynamics effects on bioreactor performance to improve biomass distribution. In the literature, few studies have dealt with biological systems coupled with fluid dynamics. Thus, the aim of the present work is to simulate the biomass distribution in a stirred bioreactor using proximity impellers at 30, 50, and 75 rpm. In this work, a modified DualSPHysics code based on the SPH method has been used to obtain the biomass distribution using a microbial kinetic model and the diffusion-advection equation coupled with the fluid dynamic equations. The work is divided into four parts: microbial and hydrodynamic validations, convergence test, analysis of mixing time, and biomass distribution. The validation results reveal the correct implementation of microbial kinetic in DualSPHysics code and the reliability of the numerical hydrodynamic results. In addition, the analysis of the mixing time and the biomass distribution have identified the performance of the proximity impellers. In summary, the results indicate that the SPH method is capable of relating biological systems and computational fluid dynamics.