Authors: Ala'aldeen T. Al-Halhouli, Stephanus Buttgenbach
Addresses: Institute for Microtechnology, Technische Universitat Braunschweig, Alte Salzdahlumer Str. 203, Braunschweig 38124, Germany. ' Institute for Microtechnology, Technische Universitat Braunschweig, Alte Salzdahlumer Str. 203, Braunschweig 38124, Germany
Abstract: In this work, analytical and numerical investigations for the effect of geometrical parameters (channel aspect ratio and radius ratio) on the friction factor in liquid flow in curved microchannels have been performed. The momentum equation in polar coordinates is first solved to estimate the effect of channel radius ratio in the liquid flow in circular curved microchannels, while the momentum equation in Cartesian coordinates is solved using a straight channel approximation to express the effect of channel aspect ratio. This effect is expressed in each model through geometrical shape factors that are finally multiplied by each other in a proposed model to predict the combined effect of geometrical parameters (height, width, inner and outer radiuses) on the flow characteristics. Obtained analytical results have been verified numerically by simulating full 3D models in the FLUENT CFD program and were found to be in good agreement with the analytical solution with an error less than 10% for a wide range of studied parameters. The friction factor model was then derived analytically and compared with previous published experimental results and conventional theory. Results showed that derived model is in good agreement with the experimental results and showed better results at low Reynolds numbers.
Keywords: friction factor; curved microchannels; microflows; liquid flow; channel aspect ratio; radius ratio; CFD; computational fluid dynamics; 3D modelling.
International Journal of Theoretical and Applied Multiscale Mechanics, 2010 Vol.1 No.3, pp.253 - 265
Published online: 07 Jun 2010 *Full-text access for editors Access for subscribers Purchase this article Comment on this article