Performance analysis of uniform and expanding cross-section microchannels for single phase and flow boiling heat transfer

Abstract

In the present experimental work a comparative study has been done to investigate the effects of single phase and flow boiling heat transfer performance of straight, uniform and expanding cross-section microchannels. Two configurations of microchannels have been fabricated on individual copper substrate (25.7 mm × 12.02 mm). In both types of geometry, 12 channels of rectangular cross-section have been fabricated having cross-section is uniform and expanding. Width at the inlet is 400 μm for both of channels and depth is 750 μm. Subcooled, deionized water with inlet temperature of 27 °C has been used. Heat transfer analysis revealed that performance of diverging channel is minimal higher for flow boiling case only, at high heat flux and low mass flow rate. For single phase convective heating its performance is not appreciable.