P.A. Kew

Bio: P.A. Kew is an academic researcher from Heriot-Watt University. The author has contributed to research in topics: Heat transfer & Boiling. The author has an hindex of 15, co-authored 35 publications receiving 1962 citations.

Heat Pipes: Theory, Design and Applications

Abstract: Heat Pipes 6th Edition, is an essential guide for practicing engineers and an ideal text for postgraduate students. This book takes a highly practical approach to the design and selection of heat pipes. This new edition has been updated with new information on the underlying theory of heat pipes and heat transfer, fully updated applications, new data sections, updated chapters on design and on electronics cooling applications. Reay's book is a useful reference as well as an accessible introduction for those approaching the topic for the first time. It contains all information required to design and manufacture a heat pipe. It is suitable for use as a professional reference and graduate text. It is revised with greater coverage of key electronic cooling applications.

Two-phase heat transfer to a refrigerant in a 1 mm diameter tube

Abstract: A study of two-phase flow and heat transfer in a small tube of 1 mm internal diameter has been conducted experimentally as part of a wider study of boiling in small channels. R141b has been used as the working fluid. The boiling heat transfer in the small tube has been measured over a mass flux range of 300–2000 kg/m2 s and heat flux range of 10–1150 kW/m2. In this paper the boiling map for a mass velocity of 510 kg/m2 s and heat flux of 18–72 kW/m2 is discussed and the problems of determining heat transfer coefficients in small channels are highlighted.

Boiling in small parallel channels

Abstract: The need for intensification of process heat exchangers has led to the development of several types of compact heat exchangers suitable for evaporation heat transfer. These heat exchangers are characterised by small multi-channel passages operating in parallel. The various regimes of two-phase flow which occur within these passages determine the heat transfer and hence the heat exchanger effectiveness. Currently there are limited data available in the literature of use in the design and selection of compact heat exchangers for evaporation.

Flow boiling of refrigerant R141B in small tubes

Abstract: Small circular and non-circular tubes are widely encountered in compact evaporators and condensers. This paper presents an experimental study of two-phase flow and heat transfer of refrigerant R141b, in small tubes. Four circular tubes with diameters of 1.1, 1.8, 2.8, 3.6 mm and one square tube of 2×2mm 2 were used in the test programme. The parameter ranges were mass flux 50 ∼ 3500kg m −2 s −1 , heat flux 1 ∼ 300kWm −2 , and inlet pressure 1 ∼ 3 bar resulting in mean boiling heat transfer coefficients of 0.1 ∼ 10 kW m −2 C −1 . It was found that local heat transfer coefficients are not only a strong function of heat flux but also a function of vapour quality and a weaker function of mass flux for the all the small tubes tested, showing that both nucleate boiling and convective evaporation occur in small tubes. The mean heat transfer coefficient was found to be is primarily a function of the heat flux, rather than the mass flux. Comparison with data in the literature shows that a general flow map developed from adiabatic two-phase flow tests can provide guidance for prediction of flow regimes in heated tubes. This study provides useful design data for two-phase flow and heat transfer in small tubes and channels.

Fundamental issues related to flow boiling in minichannels and microchannels

Abstract: Flow boiling in small hydraulic diameter channels is becoming increasingly important in many diverse applications. The previous studies addressing the effects of the channel size on the flow patterns, and heat transfer and pressure drop performance are reviewed in the present paper. The fundamental questions related to the presence of nucleate boiling and characteristics of flow boiling in microchannels and minichannels in comparison to that in the conventional channel sizes (3 mm and above) are addressed. Also, the effect of heat exchanger configuration—single-channel and multichannel—on the heat transfer and pressure drop performance is reviewed. The areas for future research are identified.

A review on phase-change materials: Mathematical modeling and simulations

Abstract: Energy storage components improve the energy efficiency of systems by reducing the mismatch between supply and demand. For this purpose, phase-change materials are particularly attractive since they provide a high-energy storage density at a constant temperature which corresponds to the phase transition temperature of the material. Nevertheless, the incorporation of phase-change materials (PCMs) in a particular application calls for an analysis that will enable the researcher to optimize performances of systems. Due to the non-linear nature of the problem, numerical analysis is generally required to obtain appropriate solutions for the thermal behavior of systems. Therefore, a large amount of research has been carried out on PCMs behavior predictions. The review will present models based on the first law and on the second law of thermodynamics. It shows selected results for several configurations, from numerous authors so as to enable one to start his/her research with an exhaustive overview of the subject. This overview stresses the need to match experimental investigations with recent numerical analyses since in recent years, models mostly rely on other models in their validation stages.