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Morteza Eslamian^*
Frontiers in Heat and Mass Transfer, Vol.2, No.4, pp. 1-20, 2011, DOI:10.5098/hmt.v2.4.3001
Abstract Recent advances in thermodiffusion (Soret effect) in binary and higher multicomponent liquid mixtures are reviewed. The mixtures studied include the hydrocarbon, associating, molten metal and semiconductor, polymer, and DNA mixtures. The emphasis is placed on the theoretical works, particularly models based on the nonequilibrium thermodynamics, although other approaches such as the statistical, kinetic and hydrodynamic approaches are discussed as well. For each mixture, the major theoretical and experimental works are discussed and the research trends and challenges are addressed. Some of the challenges include a need for combining various methods to develop a comprehensive theoretical model or at least to… More >

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Cheng-Kang Guan, James F. Klausner^*, Renwei Mei
Frontiers in Heat and Mass Transfer, Vol.2, No.4, pp. 1-6, 2011, DOI:10.5098/hmt.v2.4.3002
Abstract Pool boiling critical heat flux (CHF) has been measured for pentane, hexane, methanol, FC-72, FC-87, and R113 on a 25.4 mm diameter smooth brass horizontal surface at five different reduced pressures ranging from 0.01to 0.24. The CHF data are compared with various established CHF models as well as the new mechanistic CHF lift-off model recently proposed by the authors. The dependence of CHF on pressure is examined, and it is found that the lift-off model gives a reasonably good prediction of changes in CHF with step changes in the reduced pressure. The R113 and FC-72 boiling curves suggest that a… More >

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Muthasim Fahmy^†, Zhifa Sun
Frontiers in Heat and Mass Transfer, Vol.2, No.4, pp. 1-14, 2011, DOI:10.5098/hmt.v2.4.3003
Abstract A gas-liquid solute transfer process initiated in a closed vessel can exhibit Rayleigh-Bénard-Marangoni (RBM) convection enhanced mass transfer. For short exposure times experimental and theoretical results demonstrate that for deep liquid systems prior to solute penetration across the depth of the fluid, the stability thresholds of the system decreases with time. For thin liquid layers at longer exposure times the mass transfer enhancement under RBM convection can be affected in two ways: (1) solute penetration to the bottom liquid-solid boundary causing a departure from a penetration type concentration profile; (2) solute penetration to the top gas-solid boundary in the gas… More >

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Antti Lehtinen^a, Reijo Karvinen^b,∗
Frontiers in Heat and Mass Transfer, Vol.2, No.4, pp. 1-6, 2011, DOI:10.5098/hmt.v2.4.3004
Abstract Analytical solutions for three different flat plate conjugate heat transfer cases are presented. The cases are as follows:transient heat transfer of a thin plate with uniform heat generation; the Luikov problem in which one plate surface is kept in a constant temperature and the other one is cooled by forced convection ; and a modified Luikov problem with heat generation on one surface and convection on both surfaces of the plate. All the cases are solved for both laminar and turbulent flows with P r ≥ 1. The solutions in the paper are based on the superposition principle and analytical… More >

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A. Valan Arasu^a,*, Agus P. Sasmito^b,†, Arun S. Mujumdar^b
Frontiers in Heat and Mass Transfer, Vol.2, No.4, pp. 1-7, 2011, DOI:10.5098/hmt.v2.4.3005
Abstract The heat transfer enhancement of paraffin wax, a cheap and widely used latent heat thermal energy storage material, using nanoparticles is investigated. The effects of nanoparticle volume fraction on both the melting and solidification rates of paraffin wax are analysed and compared for Al₂O₃ and CuO nanoparticles. Present results show that dispersing nanoparticles in smaller volumetric fractions increase the heat transfer rate. The enhancement in thermal performance of paraffin wax is greater for Al₂O₃ compared with that for CuO nanoparticles. More >

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Channarong Wantha^a, Kriengkrai Assawamartbunlue^a,*
Frontiers in Heat and Mass Transfer, Vol.2, No.4, pp. 1-8, 2011, DOI:10.5098/hmt.v2.4.3006
Abstract This paper presents a study of the impact of the resonance tube on performance of a thermoacoustic stack. The resonance tube is a key component of a standing-wave thermoacoustic refrigerator. The appropriated resonance tube’s length leads to an increase of performance of the stack in terms of the temperature difference. The results also indicate that the optimal operating frequency differs from the design based on the equation of a half-wavelength. The resonance tube length is elongated to compensate for some effects that occur in the resonance tube, especially when the stack is placed in the resonance tube. The relationship of… More >

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Aravind Sathyanarayana^a, Pramod Warrier^b, Yogendra Joshi^a,*, Amyn Teja^b
Frontiers in Heat and Mass Transfer, Vol.2, No.4, pp. 1-7, 2011, DOI:10.5098/hmt.v2.4.3007
Abstract Electrical and chemical compatibility requirements of electronic components pose significant constraints on the choice of liquid coolants. Dielectric coolants such as Novec fluids and fluoroinerts are plagued by poor thermal properties. This necessitates the development of new heat transfer fluids. In this study we examine mixture formulations that provide an avenue for enhancing the properties of existing heat transfer fluids. Mixture formulations of Novec fluid (HFE 7200) with Methanol and Ethoxybutane are considered. Pool boiling experiments are performed on a copper nanowire surface. The results show an improvement of 24% and 11% in the CHF of HFE 7200 – Methanol… More >

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Seyfolah Saedodin, M.S. Motaghedi Barforoush, Mohsen Torabi^*
Frontiers in Heat and Mass Transfer, Vol.2, No.4, pp. 1-4, 2011, DOI:10.5098/hmt.v2.4.4001
Abstract In this paper, a simplifying approach for calculating the radiant energy is achieved using the concept of net radiation heat transfer and provides an easy way for solving a variety of situations. This method has been applied to calculate the net radiation heat transfer between two long concentric semi-cylinders. Then this method used to calculate reduction heat transfer when radiation shields with temperature-dependent emissivity applied between these objects. Moreover, using this method the percentage reduction in heat transfer between two surfaces was calculated. The findings reveal that, one radiation shield with lower emissivity can reduce the net heat transfer even… More >

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