Numerical studies of 3-D developing laminar flow in a microchannel

Abstract

Advances in micro-fabrication technology have allowed the use of microchannels in ultra compact, very efficient heat exchangers, which capitalize on the channels large surface area to volume ratio, to transport high heat fluxes with small thermal resistances. A 3-D rectangular channel was used as the basic physical model in this research. Both developing and fully developed regions were investigated. The concept of electric double layer (EDL) was introduced to explain the microscale deviation. An additional source term resulting from the EDL effect was introduced in the conventional momentum equation. In this work, the flow field with and without EDL effect were compared. The pro and cons of Nernst-Planck Model and Poisson-Boltzmann on describing the ions concentration were also discussed. The important of 3-D model for microchannel flows with various aspect ratios was described. The predicted results showed significant differences in the performance of microchannel with and without the EDL effects. Other factors such as developing region, effect of aspect ratio and electrical potential are important.