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Purpose: The purpose of this paper is to apply two optimization methods to the issue of sensible energy store design. Design/methodology/approach: This paper is a comparison of topology optimization and genetic algorithms. Findings: Genetic algorithms are prone to converge to local maxima while requiring significantly longer convergence times compared to topology optimization. Topology optimization resulted in structures representing parallel sheets, which are as thin as the grid allows. These configurations can maintain the maximum surface area between the low and high conductivity materials at high refinement, resulting in the best performance. Practical implications: Time required for 99 per cent store discharge is decreased by 70 per cent using a 50 × 50 optimization grid at a loading of 10 Vol.%. Originality/value: These approaches have not been compared nor applied to this specific problem before. Value is in the key finding that maximization of surface area is only possible with fins/sheets and not tree structures. This dictates the optimal solution for dynamic behaviour. [ABSTRACT FROM AUTHOR]

Purpose The purpose of this paper is to investigate the optimal geometry parameters in a dimple/protrusion-pin finned channel with high thermal performance.Design/methodology/approach The BSL turbulence model is used to calculate the flow structure and heat transfer in a dimple/protrusion-pin finned channel. The optimization algorithm is set as Non-dominated Sorting Genetic Algorithm II (NSGA-II). The high Nusselt number and low friction factor are chosen as the optimization objectives. The pin fin diameter, dimple/protrusion diameter, dimple/protrusion location and dimple/protrusion depth are applied as the optimization variables. An in-house code is used to generate the geometry model and mesh. The commercial software Isight is used to perform the optimization process.Findings The results show that the Nusselt number and friction factor are sensitive to the geometry parameters. In a pin finned channel with a dimple, the Nusselt number is high at the rear part of the dimple, while it is low at the upstream of the dimple. A high dissipative function is found near the pin fin. In the protrusion channel, the Nusselt number is high at the leading edge of the protrusion. In addition, the protrusion induces a high pressure drop compared to the dimpled channel.Originality/value The originality of this paper is to optimize the geometry parameters in a pin finned channel with dimple/protrusion. This is good application for the heat transfer enhancement at the trailing side for the gas turbine. [ABSTRACT FROM AUTHOR]

Purpose - This paper aims to develop and describe an improved process for determining the rate of heat generation in living tissue. Design/methodology/approach - Previous work by the authors on solving the bioheat equation has been updated to include a new localized meshless method which will create a more robust and computationally efficient technique. Inclusion of this technique will allow for the solution of more complex and realistic geometries, which are typical of living tissue. Additionally, the unknown heat generation rates are found through genetic algorithm optimization. Findings - The localized technique showed superior accuracy and significant savings in memory and processor time. The computational efficiency of the newly proposed meshless solver allows the optimization process to be carried to a higher level, leading to more accurate solutions for the inverse technique. Several example cases are presented to demonstrate these conclusions. Research limitations/implications - This work includes only 2D development of the approach, while any realistic modeling for patient-specific cases would be inherently 3D. The extension to 3D, as well as studies to improve the technique by decreasing the sensitivity to measurement noise and to incorporate non-invasive measurement positioning, are under way. Practical implications - As medical imaging continuously improves, such techniques may prove useful in patient diagonosis, as heat generation can be correlated to the presence of tumors, infections, or other conditions. Originality/value - This paper describes a new application of meshless methods. Such methods are becoming attractive due to their decreased pre-processing requirements, especially for problems involving complex geometries (such as patient specific tissues), as well as optimization problems, where geometries may be constantly changing. [ABSTRACT FROM AUTHOR]

Purpose - The purpose of this paper is to show how, with a view to the shortcomings of traditional optimization methods, a multi-objective optimization concerning the structure sizes of micro-channel heat sink is performed by adaptive genetic algorithm. The optimized micro-channel heat sink is simulated by computational fluid dynamics (CFD) method, and the total thermal resistance is calculated to compare with that of thermal resistance network model. Design/methodology/approach - Taking the thermal resistance and the pressure drop as goal functions, a multi-objective optimization model was proposed for the micro-channel cooling heat sink based on the thermal resistance network model. The coupled solution of the flow and heat transfer is considered in the optimization process, and the aim of the procedure is to find the geometry most favorable to simultaneously maximize heat transfer while obtaining a minimum pressure drop. The optimized micro-channel heat sink was numerically simulated by CFD software. Findings - The results of optimization show that the base convection thermal resistance contributes to maximum the total thermal resistance, and base conduction thermal resistance contributes to least. The width of optimized micro-channel and fin are 197 and 50?µm, respectively, and the corresponding total thermal resistance of the whole micro-channel heat sink is 0.838?K/W, which agrees well with the analysis result of thermal resistance network model. Research limitations/implications - The convection heat transfer coefficient is calculated approximately here for convenience, and that may induce some errors. Originality/value - The maximum difference in temperature of the optimized micro-channel cooling heat sink is 84.706?K, which may satisfy the requirement for removal of high heat flux in new-generation chips. The numerical simulation results are also presented, and the results of numerical simulation show that the optimized micro-channel heat sink can enhance thermal transfer performance. [ABSTRACT FROM AUTHOR]