Thermal-hydraulic performance investigation and optimization of additively manufactured novel MCHS with dimples

Microchannel heat sinks (MCHS) are perfect for incorporation into the systems that are smaller in size because of their compact structure. They play a key role in cooling applications where high performance and small spaces are essential. Current work presents the development of novel fractal MCHS devices with the aim of performance enhancement. Thermal and hydraulic characteristics are numerically and experimentally evaluated. Parametric optimization is also performed to find the best case of the devices for maximum overall performance. MCHS device with dimples and two branching (MCHS-D2) indicates better thermal performance than single branch (MCHS-D1) in terms of average Nusselt number ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mrow> <mml:mover> <mml:mrow> <mml:mi>Nu</mml:mi> </mml:mrow> <mml:mo stretchy="true">¯</mml:mo> </mml:mover> </mml:mrow> </mml:math> ) with maximum enhancement of 24.8%. Maximum pressure drop ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mrow> <mml:mi mathvariant="normal">Δ</mml:mi> </mml:mrow> </mml:math> P ) is also found for MCHS-D2 with 67.4% more than MCHS-D1. Grey relational analysis (GRA) based optimization reveals that MCHS-D1 at 200 ml/min offers the best thermal-hydraulic performance under equal weightage of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mrow> <mml:mover> <mml:mrow> <mml:mi>Nu</mml:mi> </mml:mrow> <mml:mo stretchy="true">¯</mml:mo> </mml:mover> </mml:mrow> </mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mrow> <mml:mi mathvariant="normal">Δ</mml:mi> </mml:mrow> </mml:math> P . When hydraulic performance is prioritized, MCHS-D1 at 100 ml/min is optimal, whereas MCHS-D2 at 300 ml/min is favored for thermal performance, highlighting the need to customize device selection to specific application priorities.