Experimental And Numerical Evaluation of Oblique Angle and Secondary Channel Width on Heat Transfer and Pressure Drop of Oblique Microchannels

Abstract

Abstract. Increase in heat dissipation from micro-electronics has necessitated the development of enhanced microchannel geometries capable of providing high heat flux cooling while maintaining optimal device temperatures. To this end, this study investigates the thermal and hydraulic behavior of oblique microchannels (OMC) featuring oblique discontinuities in otherwise continuous channel walls to enhance fluid mixing and maintain the coolant in a continuous state of thermal and hydrodynamic development, aimed at improving the overall performance. A combined experimental and numerical study is undertaken to analyze the interplay between the oblique angle (θ) and the oblique channel width (W0) on heat transfer and pressure drop characteristics of OMC. Detailed analysis of numerically derived local fluid flow and heat transfer behavior is presented to corroborate the findings. Results show the thermal and hydraulic performance is strongly governed by oblique angle than by secondary channel width. Smaller oblique angles and wider secondary channels encourage stronger secondary flow momentum which enhances fluid mixing and thereby, heat transfer performance. The local heat transfer was found to be a strong function of the microchannel's ability to generate secondary flows. Numerical parametric study reveals that the choice of oblique angle and secondary channel width dictates the surface area available for heat transfer, momentum of secondary flows, and thus, channel-to-channel fluid mixing, which ultimately influences the thermal and hydraulic performance of OMC.