Work

CFD Modeling of Shear-Rate Distribution in a Bubble Column Bioreactor: Influence of Bubble Diameter and Lift Force

Year: 2025

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide Shear rate (γ̇) is a critical parameter for evaluating the bioreactor performance. Average shear rate ( γ ˙ a v ) traditionally characterizes the shear environment, allowing comparisons among different bioreactor designs based on microorganism morphology and viability. This study presents an innovative approach using computational fluid dynamics (CFD) to assess the influence of lift force on both maximum γ ˙ max and average ( γ ˙ a v ) shear rates in a bubble column bioreactor. By employing a two-fluid Eulerian model for gas–liquid multiphase simulations, the research explored a range of specific air flows ranging from 1 to 5 vvm, specific flow rate per volume of medium, which corresponds to the superficial velocities of 4.57 to 22.86 m/s and varied average bubble diameters. Notably, including the lift force amplified the impact of bubble diameter variations on local velocity gradients, significantly affecting shear rates. The findings suggest that γ ˙ max may serve as a superior metric for comparing bioreactor performance, providing a robust framework for the optimization of biotechnological system design.

Source: ACS Omega

DOI: 10.1021/acsomega.5c06482

Authors: Ana Carolina B. Silva, Mateus N. Esperança, Alberto C. Badino, Rodrigo Béttega

Institutions: Universidade Federal de São Carlos, Universidade de São Paulo, Federal Institute of São Paulo

Language: English

Topic: Fluid Dynamics and Mixing

Subfield: Biomedical Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,935

Funders: Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Conselho Nacional de Desenvolvimento Científico e Tecnológico