Thermal transport and performance analysis of pressure- and electroosmotically-driven liquid flow microchannel heat sink with wavy wall

Husain, Afzal,Kim, Kwang-Yong Springer-Verlag 2011 Heat and Mass Transfer Vol.47 No.1

Performance analysis and design optimization of micro-jet impingement heat sink

Husain, Afzal,Kim, Sun-Min,Kim, Kwang-Yong Springer-Verlag 2013 Heat and mass transfer Vol.49 No.11

Energy Efficient Design of a Jet Pump by Ensemble of Surrogates and Evolutionary Approach

Afzal Husain,Arihant Sonawat,Sarath Mohan,Abdus Samad 한국유체기계학회 2016 International journal of fluid machinery and syste Vol.9 No.3

Energy systems working coherently in different conditions may not have a specific design which can provide optimal performance. A system working for a longer period at lower efficiency implies higher energy consumption. In this effort, a methodology demonstrated by a jet pump design and optimization via numerical modeling for fluid dynamics and implementation of an evolutionary algorithm for the optimization shows a reduction in computational costs. The jet pump inherently has a low efficiency because of improper mixing of primary and secondary fluids, and multiple momentum and energy transfer phenomena associated with it. The high fidelity solutions were obtained through a validated numerical model to construct an approximate function through surrogate analysis. Pareto-optimal solutions for two objective functions, i.e., secondary fluid pressure head and primary fluid pressure-drop, were generated through a multi-objective genetic algorithm. For the jet pump geometry, a design space of several design variables was discretized using the Latin hypercube sampling method for the optimization. The performance analysis of the surrogate models shows that the combined surrogates perform better than a single surrogate and the optimized jet pump shows a higher performance. The approach can be implemented in other energy systems to find a better design.

Energy Efficient Design of a Jet Pump by Ensemble of Surrogates and Evolutionary Approach

Husain, Afzal,Sonawat, Arihant,Mohan, Sarath,Samad, Abdus Korean Society for Fluid machinery 2016 International journal of fluid machinery and syste Vol.9 No.3

Energy systems working coherently in different conditions may not have a specific design which can provide optimal performance. A system working for a longer period at lower efficiency implies higher energy consumption. In this effort, a methodology demonstrated by a jet pump design and optimization via numerical modeling for fluid dynamics and implementation of an evolutionary algorithm for the optimization shows a reduction in computational costs. The jet pump inherently has a low efficiency because of improper mixing of primary and secondary fluids, and multiple momentum and energy transfer phenomena associated with it. The high fidelity solutions were obtained through a validated numerical model to construct an approximate function through surrogate analysis. Pareto-optimal solutions for two objective functions, i.e., secondary fluid pressure head and primary fluid pressure-drop, were generated through a multi-objective genetic algorithm. For the jet pump geometry, a design space of several design variables was discretized using the Latin hypercube sampling method for the optimization. The performance analysis of the surrogate models shows that the combined surrogates perform better than a single surrogate and the optimized jet pump shows a higher performance. The approach can be implemented in other energy systems to find a better design.

Shape Optimization of Micro-channel Heat Sink for Micro-electronic Cooling

Afzal Husain(후세인아프잘),Kwang-Yong Kim(김광용) 한국유체기계학회 2006 유체기계 연구개발 발표회 논문집 Vol.- No.-

A numerical investigation of three dimensional fluid flow and heat transfer in a rectangular micro-channel has been carried out using water as a cooling fluid in a silicon substrate. Navier-Stokes and energy equations for laminar flow and conjugate heat transfer are solved using a finite volume solver. Solutions are first carefully validated with the experimental results available; the shape of the micro-channel is then optimized using surrogate methods. Ratios of width of the micro-channel to depth and width of the fin to depth are selected as design variables. Design points are selected through three level D-optimal designs. A single objective function thermal resistance, formulated using pumping power as constraint, is optimized. Response surface analysis, Kriging and Radial basis neural network methods are applied to construct surrogates and the optimum point is searched by sequential quadratic programming.

Heat Sink Analysis for Electronic Cooling with Variable Fluid Properties

아프잘 후세인(Afzal Husain),김광용(Kwang-Yong Kim) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.5

Advanced ultra large-scale integration (ULSI) technologies, and stacking of high performance microprocessors have resulted in growing requirements for higher heat flux removal. Liquid flow microchannel heat sink integrated at the chip surface has been proposed for the viable solution for this cooling problem. The present study deals with the three-dimensional numerical fluid flow and heat transfer analysis. The study highlights the basic issues pertaining to the microflow simulation and covers essential aspects of accurately predicting the fluid flow and heat transfer phenomena in a microchannel heat sink. The microchannels with smooth walls are investigated to heat transfer performance in terms of pumping power and thermal resistance. The design variables effective to the performance of the microchannel heat sink have been investigated and optimized with the help of surrogate analysis. The effect of various design variables to the objective function which is a composite form of thermal resistance and pumping power is studied and the sensitivities of the objective function to design variables are investigated.

사다리꼴 미세유로의 형상최적화

후세인 아프잘(Afzal Husain),김광용(Kwang-Yong Kim) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.5

This work presents microchannel heat sink shape optimization procedure using Kriging method. Design variables relating to microchannel width, depth and fin width are selected, and thermal resistance has been taken as objective function. Design points are selected through a three-level fractional factorial design of sampling method. Navier-Stokes and energy equations for laminar flow and conjugate heat transfer are solved at these design points using a finite volume solver. Solutions are carefully validated with experimental results. Using the numerically evaluated objective function, a surrogate model (Kriging) is constructed and optimum point is searched by sequential quadratic programming. The process of shape optimization greatly improves the thermal performance of microchannel heat sink under constant pumping power.

Numerical Analysis of Electroosmotically Enhanced Microchannel Heat Sinks

후세인 아프잘(Afzal Husain),김광용(Kwang-Yong KIM) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11

A micro channel heat sink has been studied and optimized for mixed pressure driven and electroosmotic flows through three-dimensional numerical analysis. The effects of ionic concentration represented by zeta potential and Debye thickness are studied with the various steps of externally applied electric potential. Optimization of the micro channel heat sink has been performed considering two design variables related to the micro channel width, depth and fin width. The surrogate-based optimization is performed using a search algorithm taking overall thermal resistance as objective function. The thermal resistance is found to be more sensitive to channel width-to-depth ratio than fin width-to-depth of channel ratio.

Thermal performance investigation of enhanced receiver tube for concentrated solar collector

Mohammed Al-Harrasi,Afzal Husain,M. Zunaid Techno-Press 2022 Advances in energy research Vol.8 No.3

This study presents an experimental investigation of conventional and enhanced receiver tube performance for the application of a concentrated parabolic trough collector (CPC). The CPC system is fabricated and tested for the conventional and enhanced receiver tubes. The experiments were performed on both tubes for the change of flow rates. The temperature rise of the tube surface, as well as working fluid, were monitored for varying flow rates. The results were compared and discussed in view of enhanced CPC system performance. The results exhibited that the temperature rise of the working fluid passing through the tube was more in the case of the enhanced tube compared to the conventional receiver tube under the same flow rates.

Effectiveness of meta-models for multi-objective optimization of centrifugal impeller

Sayed Ahmed Imran Bellary,Afzal Husain,Abdus Samad 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.12

The major issue of multiple fidelity based analysis and optimization of fluid machinery system depends upon the proper constructionof low fidelity model or meta-model. A low fidelity model uses responses obtained from a high fidelity model, and the meta-model isthen used to produce population of solutions required for evolutionary algorithm for multi-objective optimization. The Pareto-optimalfront which shows functional relationships among the multiple objectives can produce erroneous results if the low fidelity models are notwell-constructed. In the present research, response surface approximation and Kriging meta-models were evaluated for their effectivenessfor the application in the turbomachinery design and optimization. A high fidelity model such as CFD technique along with the metamodelswas used to obtain Pareto-optimal front via multi-objective genetic algorithm. A centrifugal impeller has been considered as casestudy to find relationship between two conflicting objectives, viz., hydraulic efficiency and head. Design variables from the impellergeometry have been chosen and the responses of the objective functions were evaluated through CFD analysis. The fidelity of each metamodelhas been discussed in context of their predictions in entire design space in general and near optimal region in particular. Exploitationof the multiple meta-models enhances the quality of multi-objective optimization and provides the information pertaining to fidelityof optimization model. It was observed that the Kriging meta-model was better suited for this type of problem as it involved less approximationerror in the Pareto-optimal front.