Author
Said I. Abdel-Khalik
Other affiliations: King Saud University, University of Wisconsin-Madison, Georgia Tech Research Institute
Bio: Said I. Abdel-Khalik is an academic researcher from Georgia Institute of Technology. The author has contributed to research in topics: Heat flux & Heat transfer. The author has an hindex of 37, co-authored 187 publications receiving 5450 citations. Previous affiliations of Said I. Abdel-Khalik include King Saud University & University of Wisconsin-Madison.
Topics: Heat flux, Heat transfer, Divertor, Two-phase flow, Pressure drop
Papers published on a yearly basis
Papers
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TL;DR: In this paper, a systematic experimental investigation of two-phase flow patterns in microchannels was the objective of this study, using air and water, experiments were conducted in circular micro channels with 1.1 and 1.45mm inner diameters, and in semi-triangular (triangular with one corner smoothed) cross-sections with hydraulic diameters 1.09 and 149mm.
822 citations
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TL;DR: In this paper, the authors investigated void fraction and two-phase frictional pressure drop in transparent circular microchannels with 1.1 and 1.45mm inner diameters and in semi-triangular (triangular with one corner smoothed) cross-sections with hydraulic diameters 1.09 and 0.49mm.
394 citations
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TL;DR: In this article, a generalized correlation for the Nusselt number for turbulent, single-phase, forced convection in circular microchannels with diameters of 0.76 and 1.09 mm has been investigated.
356 citations
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TL;DR: In this article, a straight channel test section with integrated pressure sensors was developed with channel hydraulic diameters ranging from 25 to 100μm and compressible flow results for 6.8 Re Re
228 citations
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TL;DR: In this paper, the effects of storage capacity, storage unit heat transfer characteristics, collector area and location on the system performance are investigated for systems utilizing sodium sulfate decahydrate and paraffin wax as storage media.
184 citations
Cited by
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TL;DR: The use of a latent heat storage system using phase change materials (PCMs) is an effective way of storing thermal energy and has the advantages of high energy storage density and the isothermal nature of the storage process.
Abstract: The use of a latent heat storage system using phase change materials (PCMs) is an effective way of storing thermal energy and has the advantages of high-energy storage density and the isothermal nature of the storage process. PCMs have been widely used in latent heat thermal-storage systems for heat pumps, solar engineering, and spacecraft thermal control applications. The uses of PCMs for heating and cooling applications for buildings have been investigated within the past decade. There are large numbers of PCMs that melt and solidify at a wide range of temperatures, making them attractive in a number of applications. This paper also summarizes the investigation and analysis of the available thermal energy storage systems incorporating PCMs for use in different applications.
4,482 citations
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2,716 citations
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TL;DR: In this paper, a review of the phase change materials (PCM) and their application in energy storage is presented, where the main advantages of encapsulation are providing large heat transfer area, reduction of the PCMs reactivity towards the outside environment and controlling the changes in volume of the storage materials as phase change occurs.
2,636 citations
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TL;DR: In this paper, the phase change problem has been formulated using pure conduction approach but the problem has moved to a different level of complexity with added convection in the melt being accounted for, which makes it difficult for comparison to be made to assess the suitability of PCMs to particular applications.
Abstract: This paper reviews the development of latent heat thermal energy storage systems studied detailing various phase change materials (PCMs) investigated over the last three decades, the heat transfer and enhancement techniques employed in PCMs to effectively charge and discharge latent heat energy and the formulation of the phase change problem. It also examines the geometry and configurations of PCM containers and a series of numerical and experimental tests undertaken to assess the effects of parameters such as the inlet temperature and the mass flow rate of the heat transfer fluid (HTF). It is concluded that most of the phase change problems have been carried out at temperature ranges between 0 °C and 60 °C suitable for domestic heating applications. In terms of problem formulation, the common approach has been the use of enthalpy formulation. Heat transfer in the phase change problem was previously formulated using pure conduction approach but the problem has moved to a different level of complexity with added convection in the melt being accounted for. There is no standard method (such as British Standards or EU standards) developed to test for PCMs, making it difficult for comparison to be made to assess the suitability of PCMs to particular applications. A unified platform such as British Standards, EU standards needs to be developed to ensure same or similar procedure and analysis (performance curves) to allow comparison and knowledge gained from one test to be applied to another.
1,630 citations
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TL;DR: In this paper, the state of the art of phase change materials (PCMs) for storing solar energy is discussed. But, prior to the large-scale practical application of this technology, it is necessary to resolve numerous problems at the research and development stage.
Abstract: The continuous increase in the level of greenhouse gas emissions and the climb in fuel prices are the main driving forces behind efforts to more effectively utilise various sources of renewable energy. In many parts of the world, direct solar radiation is considered to be one of the most prospective sources of energy. However, the large-scale utilisation of this form of energy is possible only if the effective technology for its storage can be developed with acceptable capital and running costs. One of prospective techniques of storing solar energy is the application of phase change materials (PCMs). Unfortunately, prior to the large-scale practical application of this technology, it is necessary to resolve numerous problems at the research and development stage. This paper looks at the current state of research in this particular field, with the main focus being on the assessment of the thermal properties of various PCMs, methods of heat transfer enhancement and design configurations of heat storage facilities to be used as a part of solar passive and active space heating systems, greenhouses and solar cooking.
1,173 citations