Optimization of Microchannel Geometries to Enhance Convection Cooling of Parallel Plate Duct Flow


Forced convection heat transfer from arrays of microchannels was considered for fixed volume and fixed pressure drop constraints. Order of magnitude relationships were developed for the optimal dimension of a number of fundamental duct shapes including the parallel plate channel with rectangular,square, rhombus, isosceles right triangle, circular duct and elliptic duct. Using the exact analysis method to produce an approximate expression for the optimal duct shape was developed for all ducts considered. Where approximate analytical results show that the optimal shape is the parallel plate channel duct array but withaddition a triangular or rectangular duct to the parallel plate, where the rectangular model give a percent of (52%) increasing in the heat dissipation higher than the circular at an aspect ratio about (b/a=0.4), while give a percent of increase about (87%) in the same aspect ratio compared with rhombus duct model in heat dissipation due to their ability to provide the most efficient arrays in a fixed volume. Comparison of the approximate results with exact results from theliterature show excellent agreement for the optimal duct dimensions.