Abstract
Microchannel heat exchangers have become increasingly important for dissipating high heat fluxes in various applications, including electronics cooling, power generation, and refrigeration systems. Among the heat transfer mechanisms in microchannels, flow boiling offers significant advantages due to its efficient heat removal capabilities and compact design. Computational Fluid Dynamics (CFD) plays a crucial role in understanding and optimizing flow boiling heat transfer in microchannels. This paper reviews two modeling approaches, one employing the Volume of Fluid (VOF) method and the other utilizing a semi-mechanistic boiling model under the Eulerian multiphase framework, implemented in ANSYS Fluent. While the VOF method does not rely on empirical models, it may entail long simulation times, whereas the semi-mechanistic boiling model allows for quicker turnaround. Two validation studies are presented to assess the accuracy of the CFD models implemented in ANSYS Fluent. The first validation study involves water as the working fluid, mimicking typical coolant applications in electronics cooling. The second validation study focuses on R134a as the working fluid, representing refrigerant applications in microchannel heat exchangers. These validation studies demonstrate the utility of CFD simulations using ANSYS Fluent in elucidating heat transfer mechanisms and optimizing microchannel geometries for diverse applications.
