Z. Aouachria^a,*, F. Rouichi^a, D. Haddad^b

Frontiers in Heat and Mass Transfer, Vol.3, No.2, pp. 1-6, 2012, DOI:10.5098/hmt.v3.2.3004

Abstract Natural convection flow past a vertical porous plate in a porous medium is studied numerically, by taking into account the Dufour and Soret effects. The similarity equations of the problem considered are obtained by using usual similarity technique. This system of ordinary differential equations, which are solved numerically by using the Nachtsheim -Swigerst hooting iteration technique together with a sixth order Runge-Kutta integrations scheme. The results show that Soret and Dufour effects do not appreciably influence the velocity, temperature and concentration fields, but rather only tend to increase the mass and energy flux due to the added contributions. More >

Nikola Stosic^**, Ian K. Smith, Ahmed Kovacevic

Frontiers in Heat and Mass Transfer, Vol.3, No.2, pp. 1-7, 2012, DOI:10.5098/hmt.v3.2.3003

Abstract Due to fast rotation of screw compressor rotors, temperature is uniform in the rotor cross section and temperature field is a function of the axial coordinate only. Apart of that the rotors in one cross section the rotors are simultaneously heated by hot gas on one side while cooled at another side by cold gas. As a result of identification of the main modes of heat transfer both in the rotors and between the rotors and their surroundings and the relative significance of each, a novel procedure is suggested to cool the rotors by injection of minute quantities of a… More >

Frantisek Kavicka^a,*, Jana Dobrovska^b, Karel Stransky^a, Bohumil Sekanina^a, Josef Stetina^a

Frontiers in Heat and Mass Transfer, Vol.3, No.2, pp. 1-9, 2012, DOI:10.5098/hmt.v3.2.3002

Abstract Corundo-baddeleyit material (CBM) – EUCOR – is a heat- and wear-resistant material even at extreme temperatures. This article introduces an original numerical model of solidification and cooling of this material in a non-metallic mold. The second, cooperating model of chemical heterogeneity and its application on EUCOR samples prove that the applied method of measuring the chemical heterogeneity provides the detailed quantitative information on the material structure and makes it possible to analyze the solidification process. The verification of both numerical models was conducted on a real cast 350 x 200 x 400 mm block. More >

Yunpeng Ren, J. K. Chen^*, Yuwen Zhang

Frontiers in Heat and Mass Transfer, Vol.3, No.2, pp. 1-7, 2012, DOI:10.5098/hmt.v3.2.3001

Abstract Heat transfer in a copper film irradiated by a femtosecond (fs) laser pulse train and by an integrated dual laser beam of a nanosecond pulse with a fspulse train was studied using the semi-classical two-temperature model. The critical point model with three Lorentzian terms was employed to characterize transient optical properties for the laser energy deposition. The effects of pulse number and separation time on the thermal response were investigated. The results showed that with the same total energy in a fs-pulse train, more pulses for shorter separation time, e.g., 1 ps, and fewer pulses for longer separation time, e.g.,… More >

Milind S. Patil^a,*, Ramchandra S. Jahagirdar^b, Eknath R. Deore^a,†

Frontiers in Heat and Mass Transfer, Vol.3, No.3, pp. 1-5, 2012, DOI:10.5098/hmt.v3.3.3008

Abstract Convection heat loss inevitably occurs in receivers of high concentrating solar concentrators. All the concentrators are need to be tack during the operation and hence the position of the receiver is changing continually. The angle of the receiver axis will then play an important role in the heat loss. Few researches were reported for the hemispherical cavity receivers numerically. The paper presented here is an experimental investigation natural convection heat loss from hemispherical cavity receiver. Cavity receiver of diameter 540 mm was tested. It is observed that the heat loss was minimum for 90° and maximum for 0°. More >

Ahmad Najjaran¹, Ali R. Tahavvor, Abdolkarim Najjaran, Mohammad A. Ahmadfard

Frontiers in Heat and Mass Transfer, Vol.3, No.3, pp. 1-6, 2012, DOI:10.5098/hmt.v3.3.3007

Abstract In this paper, external radiation heat transfer coefficient and flux of a standing human body model are calculated for different emissivity coefficients and various temperature differences. To do this, a standing human body sample is designed in such a way that hands and feet are totally open and stretched. Soles are in contact with the ground and so do not have heat transfer. The results are extracted by weighted average method. Despite the existence of the air around the body in reality, the convection heat transfer of human body with the surrounding air is neglected in order to prevent errors… More >

Arafat A. Bhuiyan^a,1, A. K. M. Sadrul Islam^a, M. Ruhul Amin^b

Frontiers in Heat and Mass Transfer, Vol.3, No.3, pp. 1-9, 2012, DOI:10.5098/hmt.v3.3.3006

Abstract This numerical analysis presents the airside performance of a wavy fin-and-tube heat exchanger having 4 row configurations considering steady, incompressible and 3D flow using Commercial CFD Code ANSYS CFX 12.0. Results are presented in the form of friction factor (f), Colburn factor (j) and efficiency index (j/f). The numerical procedure has been validated by comparison with published numerical and experimental results and good agreement has been observed. A series of numerical calculations have been carried out in order to analyze the influence of various geometric characteristics on different fields as well as on the heat transfer and pressure drop and… More >

Mohammad Izadifar^a,b,* , Jane Alcorn^c

Frontiers in Heat and Mass Transfer, Vol.3, No.3, pp. 1-7, 2012, DOI:10.5098/hmt.v3.3.3005

Abstract Applying local volume averaging method a mathematical model including liver porosity, tortuosity, permeability, unbound drug fraction, drugplasma diffusivity, axial/radial dispersion and hepatocellular metabolism parameters was developed for hepatic drug elimination. The model was numerically solved using implicit finite difference method to describe drug concentration gradient with time across the liver. Statistically validated by observations and other models, the model suggested axial dispersion as a significant variable in drug distribution across the liver. Sensitivity analyses revealed that lower liver porosity resulted in faster drug distribution across the liver, and bioavailability was sensitive to the interaction between unbound fraction and intrinsic clearance. More >

Pranab Kumar Mondal^*, Sanchayan Mukherjee

Frontiers in Heat and Mass Transfer, Vol.3, No.3, pp. 1-6, 2012, DOI:10.5098/hmt.v3.3.3004

Abstract The present paper deals with the analytical investigation for the limiting value of Nusselt number, including the effect of viscous dissipation on heat transfer for a laminar shear driven flow between two infinite parallel plates, where the bottom plate is fixed and the top plate is moving in an axial direction at a constant speed. The study concentrates on hydro-dynamically fully developed flow of a Newtonian fluid of constant properties without considering the axial conduction in the fluid. To investigate the effect of viscous dissipation on heat transfer by defining the limiting Nusselt number, plates are kept at constant equal… More >

Keyong Cheng^a,b,*, Chunzi Zhang^c, Wei Chen^a,b, Shiqiang Liang^a,†, Yongxian Guo^a,d, Xiulan Huai^a

Frontiers in Heat and Mass Transfer, Vol.3, No.3, pp. 1-6, 2012, DOI:10.5098/hmt.v3.3.3003

Abstract A film cooling method with chemical heat sink for gas turbine blades is proposed. In this method, an endothermic reaction of cooling stream occurs due to the heating from the mainstream, which leads to an improvement of film cooling effectiveness. The proposed method at different blowing ratios are computed and compared with the conventional one. The simulation result shows that due to the exsitence of the chemical heat sink the proposed method can enhance film cooling effectiveness not only in the streamwise direction, but also in the spanwise direction. More >