Complex heat transfer analysis in heat exchanger with constructal cylindrical fins

This paper documents a 3-D numerical analysis and theoretical prediction in novel micro-channel heat sinks comprise of three configurations. The first design has solid fins, the second model has half-hollow fins placed on micro-channel, while in the third design, hollow fins are mounted on the heat sink. The objective of the study is to maximise the dimensionless thermal conductance subject to fixed volume. A microelectronic device released high-density heat flux at the bottom of heat sink and liquid of Reynolds number range between 400 and 500, is applied at entrance of the boundary under laminar forced convection scheme to dispel heat deposited in the cooling channels and the internal parts of the hollows. A multi-objective broadscale step-by-step code is used to perform the optimisation and the results shows that the micro-channel with full-hollows has the highest thermal conductance at Rew <475, followed by solid fins before half-drilled fins. Theoretical analysis is conducted on the three configurations using the intersection of asymptotes method, and the results compared favorably with numerical solution. The findings indicate that the theoretical solution tends to over-predict the numerical results within a certain range of Bejan number. Code validation is performed, and the results align with existing literature.