Thermal Performance Evaluation of Micro Pin-Fin Heat Exchangers: Part II-Numerical Simulation and Fabrication Demonstration

In this work, thermal simulation based on the outcomes of topology optimization through EGM (Entropy generation minimization) using an in-house PSO algorithm has been carried out. Thermal performances such as Nusselt number, Reynolds number, Pressure drop, and Thermal performance index are evaluated through arrayed micro pin-fins (MPFs) heat sink patterns. Four heat sinks of unconventional cross-section profiles are considered, viz. droplet, piranha, elliptical, and aerofoil. The PSO obtained optimal value for inline and staggered patterns of the characteristic length, height, inter-MPF gaps, cross-sectional area, perimeter, and density of the MPFs are utilized in computational model development. Subsequently, a comparative analysis regarding the thermal performance of various MPFs is performed under constant heat flux and laminar flow regime conditions. Optimal arrayed piranha MPFs in staggered pattern has shown the finest thermal performance index dissipating heat flux up to 2 x 10(6) W/m(2). An attempt to produce the optimized profile of piranha MPFs heat sink is successfully fabricated to verify the micromanufacturing feasibility of miniaturized arrayed heat sinks. For this, combined Reverse micro-electro-discharge machining (R mu EDM) and Laser beam micromachining (LB mu M) processes are utilized for neat-net-shape production of the optimal heat sink configuration.