The Impact of Altering an Aspect Ratio on the Instabilities of Flow Boiling Characteristics in a Rectangular Microchannel

This study varied the aspect ratio of a single microchannel to analyze fluid flow and heat transmission. The tests used a 0.7-mm-wide, 0.3-mm-deep, 60-mm-long micro-channel. The input temperature was 30℃ and deionized water was used. Reynolds numbers examined were 166-2550. The fanning friction factor's link with laminar and turbulent flow can reliably predict experimental outcomes, according to calculations and tests. The Nusselt number also rises with the Reynolds number. Increased aspect ratios improve heat transfer at all Reynolds numbers. Under high mass flow circumstances, increasing aspect ratio from 0.42 to 2.4 reduced wall superheat by 22.7%. At high heat flux, a mass flow rate of 450 kg/m2 improves heat transfer coefficient more than 250 kg/m2. The biggest improvements are 6.13% and 4.08%. The study shows a correlation between wall heat flow and pressure drop. Inversely, aspect ratio decreases pressure drop. With increasing aspect ratio, nucleate boiling was delayed. As mass flux increased, pressure drop oscillations decreased. Pressure drops oscillate at 2.5 and 2.6 kilopascals for aspect ratios of 0.42 and 2.4.