A numerical study on the hydrodynamic and thermal effects of microscale liquid flows past microstructures
A study of hydrodynamic and thermal effects of microscale liquid flows past microstructures is performed computationally in three-dimensional channels. A range of Reynolds numbers (based on mean velocity and hydraulic diameter) from 50 to 1078 is examined along with constant power inputs of 50, 100, and 200 Watts. Adding microstructures to the interior of the microchannel wall creates recirculation regions and vorticity structures which grow with flow rate and enhance the mixing and heat transfer within the microchannel. "Turbulent-like" characteristics are very desirable for micro-electro-mechanical systems, which is a growing industry. In addition, the microstructures increase the surface-area-to-volume ratio while only slightly increasing the pressure needed to drive the flow. The numerical results of hydrodynamics effects are compared to experiments showing that conventional computational fluid dynamics codes, solving the Navier-Stokes equations derived from continuum theory, accurately model microscale liquid flows under certain conditions. The percent error between numerical and experimental results increases as the flow rate increases, leading to conclusions about the possible foundation for discrepancies.