Department of Mechanical Engineering, IIT Guwahati, Guwahati-781039, Assam, India
Department of Mechanical Engg., Indian Institute of Technology Guwahati, Guwahati 781039, India
Microchannel heat exchanger (MCHX) devices are very promising in high heat flux removal techniques. MCHX led to the development of highly efficient miniaturized electronics and microfluidics devices. The fluid flow and heat transfer in micro and mini-scale channels have been extensively studied. The exact phenomenon of heat transfer and fluid flow at the microscale dimension is still mysterious for researchers. The microchannel and minichannels with rectangular, circular, and trapezoidal cross-sections are widely investigated, but limited data is available for the triangular microchannel. The hydraulic and thermal loss in the microchannel flow is mainly
calculated by determining the pressure drop and temperature difference, as suggested in the available literature. In the current work, a second law analysis is performed numerically for heat transfer and fluid flow in the triangular miniature channel. The entropy generation is determined to calculate the hydraulic and thermal losses of fluid flow. The effect of changing channel apex angle and channel depth on entropy generation is also analyzed. The entropy generation due to hydraulic loss is in increasing trends with reducing apex angle. Thermal irreversibility increases first with increasing channel apex angle up to 105° and then decreases with further increment in channel angle. The irreversibility is higher for lower depth channels which reduces on increasing
channel depth. The entropy generation due to hydraulic loss is in reverse trend with friction factor. The thermal irreversibility is directly dependent on heater wall temperature and follows the same trend.