Multi-objective NSGA-II based shape optimisation of the cross-sectional shape of passively cooled heat sinks. Issue 3 (16th July 2021)

• Record Type: Journal Article
• Authors: Santhanakrishnan, Mani Sekaran; Tilford, Tim; Bailey, Chris
• Is Part Of: International journal of numerical methods for heat & fluid flow. Volume 32:Issue 3(2022)
• Page Start: 1025
• Page End: 1045
• Publication Date: 2021-07-16
• Subjects: CFD -- Natural convection -- Genetic algorithm -- Heat sink design -- Shape optimisation; Heat -- Transmission -- Mathematics -- Periodicals; Fluid dynamics -- Mathematics -- Periodicals; 536.2
• DOI: 10.1108/HFF-10-2020-0656
• Languages: English
• ISSNs: 0961-5539

Abstract

Abstract : Purpose: The purpose of the study is to optimise the cross-sectional shape of passively cooled horizontally mounted pin-fin heat sink for higher cooling performance and lower material usage. Design/methodology/approach: Multi-objective shape optimisation technique is used to design the heat sink fins. Non-dominated sorting genetic algorithm (NSGA-II) is combined with a geometric module to develop the shape optimiser. High-fidelity computational fluid dynamics (CFD) is used to evaluate the design objectives. Separate optimisations are carried out to design the shape of bottom row fins and middle row fins of a pin-fin heat sink. Finally, a computational validation was conducted by generating a three-dimensional pin-fin heat sink using optimised fin cross sections and comparing its performance against the circular pin-fin heat sink with the same inter-fin spacing value. Findings: Heat sink with optimised fin cross sections has 1.6% higher cooling effectiveness than circular pin-fin heat sink of same material volume, and has 10.3% higher cooling effectiveness than the pin-fin heat sink of same characteristics fin dimension. The special geometric features of optimised fins that resulted in superior performance are highlighted. Further, Pareto-optimal fronts for this multi-objective optimisation problem are obtained for different fin design scenarios. Originality/value: For the first time, passively cooled heat sink's cross-sectional shapes are optimised for different spatial arrangements, using NSGA-II-based shape optimiser, which makes use of CFD solver to evaluate the design objectives. The optimised, high-performance shapes will find direct application to cool power electronic equipment.