Numerical Simulation of Single Phase Liquid Flow in Narrow Rectangular Channels With Structured Roughness Walls

Laminar flow in rough channels is receiving considerable attention recently due to its application in microfluidic devices. Developing a proper understanding of the fundamental effects of roughness in narrow channels is essential. In the present study, single-phase laminar flow of an incompressible fluid through narrow rectangular channels with structured roughness walls is investigated numerically using CFD software, FLUENT. The results for smooth channel geometries are first compared with the previously validated experimental data of Brackbill [1]. Triangular ribbed roughness structures, defined by pitch and height, are incorporated in the CFD model and the fully developed region is analyzed. Pressure drop results from CFD simulations are presented and the friction factor, f , is calculated for comparison with published experimental results of Brackbill and Kandlikar [2-4] and Brackbill [1]. The validated numerical scheme will be used in future work for the evaluation of the effect of different roughness features on laminar flow.