Constructal flow orientation in conjugate cooling channels with internal heat generation

Abstract

This paper presents the development of the three-dimensional flow architecture of conjugate cooling channels in forced convection with internal heat generation within the solid for an array of circular cooling channels with different flow orientation. Three flow orientations were studied: array of channels with parallel flow; array of channels in which the flow in every second row is in a counter direction with its neighbours, and flows in all the arrays of channels are in counter flow relative to each other. The geometric configurations were determined in such a way that the peak temperature was minimised subject to the constraint of fixed global volume of solid material. The degrees of freedom of the design were hydraulic diameter and channel to channel spacing. A gradient-based optimisation algorithm was applied to search for the best optimal geometric configurations that improve thermal performance by minimising thermal resistance for a wide range of dimensionless pressure differences. The effect of porosities, applied pressure difference, flow orientation and heat generation rate on the optimal 2 hydraulic diameter and channel to channel spacing is reported. The results show that the effects of dimensionless pressure drop on minimum thermal resistance were consistent with those obtained in the open literature.

Constructal heat transfer and fluid flow enhancement optimization for cylindrical microcooling channels with variable cross‐section

“…The optimization then searches for design candidates and later determines the minimized objective functions with the corresponding optimal design variables. Equation (17) shows the design variables ranges for the optimization: Figure 9 presents the graph of minimized, global, dimensionless thermal resistance against the Bejan number and porosity. The result indicates that the minimized thermal resistance decreases as the Bejan number and porosity increase.…”

“…1,2 Constructal design has been used in biological sciences, social organizations, physics, and engineering for the design of flow systems. [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] For example, in engineering problems, configuration dimension is not known in advance before the optimization begins. It has to be determined optimally, so that the system performance is enhanced.…”

Heat transfer enhancement using combined microchannel with vertical rectangular micro fins

“…In a bid to investigate the constructal law and its usefulness in geometric optimisation, Bello-Ochende et al (2013) performed a numerical and analytical study of square flow channels using a vascularised material having localised internal cooling property with heat flux applied at one side of the heat sink. The goal of the study was to reduce the highest temperature in the material body of the solid substrate.…”

Constructal Optimizations of Line-to-Line Vascular Channels with Turbulent Convection Heat Transfer

“…Since it was proposed, constructal theory has been widely used in various fields [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. As one of the main fields, it has opened up new research on the optimizations of heat and mass transfer, such as heat source [ 23 , 24 , 25 , 26 ], heat conduction [ 27 , 28 , 29 , 30 ], convection heat transfer [ 31 , 32 , 33 ] and heat exchange equipment [ 34 , 35 , 36 , 37 , 38 ].…”