Numerical study of the effect of surface roughness on the mass transport in a 3D microchannel bioreactor

• Main Authors: Hsiu-Ya Chan, 詹琇雅
• Other Authors: Chih-Hao Teng
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/27655403990232504044

碩士 === 中原大學 === 土木工程研究所 === 98 === Abstract 　　The environment of bioreactor has very tremendous influence on the synthesis and the detoxification function of hepatocytes. Furthermore, the most important consideration inside a bioreactor is that the concentration of the nutrient fluid must be more than the lowest consumption limit which the cell can maintain the multiplication so the mortality can be reduced. In this study, the concentration distribution of the bioreactor is numerically simulated by the finite element software to find out the oxygen distribution of the nutrient fluid due to the geometrical shape and the bottom roughness of the bioreactor. The main dimensionless parameters in both smooth and roughness three-dimensional microchannels such as roughness size ratio (α) and roughness distribution ratio (β), Peclet number (Pe), Damkohler number (Da) and the Michaelis-Menten constant (Km ) are used to discuss the concentration distribution, the effects of oxygen consumption rate (Δj%) and the lowest concentration ratio（Cmin ）on the bottom of microchannel bioreactors. The concentration distribution oscillating in the baseline of rough microchannels along the flow direction, it increases significantly when α value increase, and it decreases in smooth regions between particles a lot when compared with the distribution with the smooth channels. The shear stress distributions of the bottom also show significant effect on the concentration distributions. Overall, the concentrations increase when Pe value and value increases and Da value decreases, in roughness parts, the effects of Pe value and value are not significant but increase as Da value increases. Furthermore, in terms of oxygen consumption rate (Δj%) and the lowest concentration ratio（Cmin ）on the bottom of microchannel bioreactors, Δj% increase when α value and Pe value increase or β value and Da value decrease. The effect of dimensionless parameters are significant in the lowest concentration ratio（Cmin）, but geometric parameters are not. For the cell concentration distributions, when designing a bioreactor, we should take a balance between the α value, channel length and initial velocity of the bioreactor.