Constructal Optimizations for Heat and Mass Transfers Based on the Entransy Dissipation Extremum Principle, Performed at the Naval University of Engineering: A Review

Abstract

Combining entransy theory with constructal theory, this mini-review paper summarizes the constructal optimization work of heat conduction, convective heat transfer, and mass transfer problems during the authors’ working time in the Naval University of Engineering. The entransy dissipation extremum principle (EDEP) is applied in constructal optimizations, and this paper is divided into three parts. The first part is constructal entransy dissipation rate minimizations of heat conduction and finned cooling problems. It includes constructal optimization for a “volume-to-point” heat-conduction assembly with a tapered element, constructal optimizations for “disc-to-point” heat-conduction assemblies with the premise of an optimized last-order construct and without this premise, and constructal optimizations for four kinds of fin assemblies: T-, Y-, umbrella-, and tree-shaped fins. The second part is constructal entransy dissipation rate minimizations of cooling channel and steam generator problems. It includes constructal optimizations for heat generating volumes with tree-shaped and parallel channels, constructal optimization for heat generating volume cooled by forced convection, and constructal optimization for a steam generator. The third part is constructal entransy dissipation rate minimizations of mass transfer problems. It includes constructal optimizations for “volume-to-point” rectangular assemblies with constant and tapered channels, and constructal optimizations for “disc-to-point” assemblies with the premise of an optimized last-order construct and without this premise. The results of the three parts show that the mean heat transfer temperature differences of the heat conduction assemblies are not always decreased when their internal complexity increases. The average heat transfer rate of the steam generator obtained by entransy dissipation rate maximization is increased by 58.7% compared with that obtained by heat transfer rate maximization. Compared with the rectangular mass transfer assembly with a constant high permeability pathway (HPP), the maximum pressure drops of the element and first-order assembly with tapered HPPs are decreased by 6% and 11%, respectively. The global transfer performances of the transfer bodies are improved after optimizations, and new design guidelines derived by EDEP, which are different from the conventional optimization objectives, are provided.

Effect of surface roughness on the performance of heat exchanger

“…Similarly, electrical potential energy stored in a capacitor is QV/2, and thermal potential energy stored in a system is UT/2. Thus, entransy (G) is defined as the half of the product of internal energy (U) and temperature (T) and expressed as [17][18][19][20][21][22][23][24][25][26][27];…”

“…Exergy analyses at different conditions have been performed on heat exchangers and power plants by Geete et al and Ibrahim et al, and after analyses they found minimum exergy destruction is good for better outputs from thermal systems [12][13][14][15][16]. Chen et al, Feng et al, Guo et al and other researchers have worked on entransy concepts for heat exchanging devices, and they applied entransy dissipation, entransy dissipation-based thermal resistance and entransy dissipation number on thermodynamic systems for comparative performance analyses and concluded that these parameters should be minimum [17][18][19][20][21][22][23][24][25][26][27][28]. In this research work, rates of entropy generation, exergy destruction, entransy dissipation, entransy dissipationbased thermal resistance, entransy dissipation numbers, effectiveness and entropy generation numbers have been calculated at different operating conditions to get better conditions at which performance of counter flow doublepipe heat exchanger will be the best.…”

Constructal Design of an Arrow-Shaped High Thermal Conductivity Channel in a Square Heat Generation Body

“…Bejan [ 1 ] stated the constructal law after further studying the formation of urban street networks, and applied it to the optimization of the heat dissipation structure of an electronic device (ED) [ 2 ]. Since the introduction of the constructal theory [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ], it has been applied to design various heat dissipation bodies, such as rectangular [ 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 ], triangular [ 32 , 33 , 34 , 35 , 36 , 37 ], square [ 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 ] and discal [ 48 , 49 , 50 , 51 , 52 , 53 ,…”

Performance Optimization of a Condenser in Ocean Thermal Energy Conversion (OTEC) System Based on Constructal Theory and a Multi-Objective Genetic Algorithm

“…Constructal theory [ 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 ] was put forward by Professor Bejan in 1996. The corresponding constructal law [ 27 , 28 ] is “For a finite-size flow system to persist in time (to live), its configuration must change in time such that it provides easier and easier access to its currents.” The structural designs for living and non-living systems can be performed by applying constructal theory, including the structural designs of HEs.…”