Mass transport in a microchannel bioreactor with a porous wall.
A two-dimensional flow model has been developed to simulate mass transport in a microchannel bioreactor with a porous wall. A two-domain approach, based on the finite volume method, was implemented. For the fluid part, the governing equation used was the Navier-Stokes equation; for the porous medium region, the generalized Darcy-Brinkman-Forchheimer extended model was used. For the porous-fluid interface, a stress jump condition was enforced with a continuity of normal stress, and the mass interfacial conditions were continuities of mass and mass flux. Two parameters were defined to characterize the mass transports in the fluid and porous regions. The porous Damkohler number is the ratio of consumption to diffusion of the substrates in the porous medium. The fluid Damkohler number is the ratio of the substrate consumption in the porous medium to the substrate convection in the fluid region. The concentration results were found to be well correlated by the use of a reaction-convection distance parameter, which incorporated the effects of axial distance, substrate consumption, and convection. The reactor efficiency reduced with reaction-convection distance parameter because of reduced reaction (or flux), and smaller local effectiveness factor due to the lower concentration in Michaelis-Menten type reactions. The reactor was more effective, and hence, more efficient with the smaller porous Damkohler number. The generalized results could find applications for the design of bioreactors with a porous wall.
Chen
Xiao Bing
XB
Dynamics Lab., E1-02-01, Department of Mechanical Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore 117576. mpecx@nus.edu.sg
Sui
Yi
Y
Lee
Heow Pueh
HP
Bai
Hui Xing
HX
Yu
Peng
P
Winoto
S H
SH
Low
Hong Tong
HT
D057005:Bioengineering; D001692:Biological Transport; D001696:Biomechanical Phenomena; D019149:Bioreactors / Q000706:statistics & numerical data; D057446:Hydrodynamics; D008954:Models, Biological; D016062:Porosity; D012212:Rheology