Archive issue - vol.2 No.1



   No.   Author(s) - Title
Pages

   1.
 

 In memory of Professor Janusz Witold ELSNER --
 

5-8
 

   2.
 

 Al-Nimr M.A. and Darabseh T. -- Analytical solution to transient laminar fully developed free convection in open-ended vertical channel embedded in porous media
 

9-32
 

   3.
 

 Hossain M.A., Alam K.C.A. and Rees D.A.S. -- MHD forced and free convection boundary layer flow along a vertical porous plate
 

33-51
 

   4.
 

 Watanabe K. and Kurashige M. -- Fundamental solutions for a fluid-saturated, isotropic, poroelastic, infinite solid having zero permeability in one direction
 

53-71
 

   5.
 

 «arpinlioglu M.÷. -- Development of a boundary layer downstream of flow separation indicative of leading edge contamination on a flat plate
 

73-88
 

   6.
 

 Shulman Z.P., Khusid B.M. and Fain I.V. -- Effect of blood perfusion variation on heat transfer under local hyperthermia treatment
 

89-106
 

   7.
 

 Mansour M.A., El-Hawary H.M. and Gorla R.S.R. -- Chebyshev approximation for heat transfer from a semi-infinitely large porous plate in a viscoelastic fluid
 

107-116
 

   8.
 

 Chen F.K. and Tseng P.C. -- Calculation of the restraining force for the drawbead in the stamping process
 

117-132
 

   9.
 

 Kmieś A. -- Analysis of the gas-solid flow in a riser reactor
 

133-152
 

 



2.

ANALYTICAL SOLUTION TO TRANSIENT LAMINAR
FULLY DEVELOPED FREE CONVECTION IN OPEN-ENDED
VERTICAL CHANNEL EMBEDDED IN POROUS MEDIA

Moh'd Ahmad AL-NIMR, Tariq DARABSEH

Mechanical Engineering Department
Jordan University of Science and Technology
Irbid-JORDAN

     Using Green's function method, analytical solutions to transient fully developed natural convection in an open-ended vertical porous channel are presented. Four fundamental boundary conditions have been investigated and the corresponding fundamental solutions are obtained. These four fundamental boundary conditions are obtained by combining each of the two conditions of having one boundary maintained at uniform heat flux or at uniform wall temperature with each of the conditions that the opposite boundary is kept isothermal at the inlet fluid temperature or adiabatic. Expressions for the transient fully developed volumetric flow rate the, mixing cup temperature and the local Nusselt number are given for each case. These fundamental solutions may be used to obtain solutions satisfying more general thermal boundary conditions.

Key words:

porous media, analytical solutions, free convection, vertical channel, transient behaviour.

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3.

MHD FORCED AND FREE CONVECTION BOUNDARY LAYER FLOW
ALONG A VERTICAL POROUS PLATE

M. A. Hossain, K. C. A. Alam

Department of Mathematics, University of Dhaka
Dhaka 1000, BANGLADESH

D. A. S. Rees
School of Mechanical Engineering, University of Bath
Bath BA2 7AY, U.K.

     This paper details a study of the combined forced and free convection boundary layer flow of a viscous, incompressible and electrically conducting fluid along a vertical porous plate in the presence of transverse magnetic field. Numerical solutions of the local non-similar boundary layer equations governing the flow and energy are obtained by employing an implicit finite difference approximation together with the Keller box method. The results thus obtained are compared with perturbation solutions in terms of both the local rate of heat transfer and the local surface shear stress for different physical parameters. The dimensionless velocity and temperature functions in the flow are also presented.

Key words:

magnetohydrodynamic, convection, transpiration, boundary layer.

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4.

FUNDAMENTAL SOLUTIONS FOR A FLUID-SATURATED,
ISOTROPIC, POROELASTIC, INFINITE SOLID HAVING ZERO
PERMEABILITY IN ONE DIRECTION

Koya WATANABE

Showa Civic Design Co.Nagai 17-20-20
Morioka 020, JAPAN

Michio KURASHIGE
Iwate University Department of Mechanical Engineering
Ueda 4-3-5, Morioka 020, JAPAN

     Fundamental solutions have been obtained for a fluid-saturated, isotropic, poroelastic, infinite solid having zero permeability in one direction for an instantaneous fluid point source and instantaneous point forces in and perpendicular to the zero-permeability direction. The solutions are aimed at their application to simulation of the waterf looding in low permeability oil reservoirs, one of the techniques to enhance oil recovery. Zero permeability in one direction may be a good approximation because the flow of oil or injected water predominates in the horizontal direction. Furthermore, this assumption may dramatically simplify expected applications because it eliminates the adverse contributions of the bounding surfaces of the reservoir to complexity in crack analyses.

Key words:

fundamental solution, poroelastic solid, pore fluid, point source, point force, permeability.

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5.

DEVELOPMENT OF A BOUNDARY LAYER DOWNSTREAM
OF FLOW SEPARATION INDICATIVE OF LEADING
EDGE CONTAMINATION ON A FLAT PLATE

Melda ÷.«ARPINLIOGLU

Gaziantep University Faculty of Engineering
Department of Mechanical Engineering
Gaziantep, TURKEY

     An experimental investigation was carried out on the influence of the leading edge contamination upon the flow field on a swept flat plate. A leading edge flow separation was produced to simulate the edge contamination problem. The development of the attached boundary layer downstream of the separated flow region has been studied through the mean flow parameters. A rather classical method of measurement by means of pressure probes was used in the investigation. Based on the growth characteristics of the attached boundary layer, the critical conditions representing the origin of turbulent flow on the plate have been estimated.

Key words:

leading edge contamination, transition, streamwise velocity, crosswise velocity.

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6.

EFFECT OF BLOOD PERFUSION VARIATION ON HEAT TRANSFER
UNDER LOCAL HYPERTHERMIA TREATMENT

Z.P.SHULMAN, B.M.KHUSID, I.V.FAIN

A.V.Luikov Heat and Mass Transfer Institute
Belarussian Academy of Sciences
15 P.Brovka Street, Minsk 220072, REPUBLIC OF BELARUS

     A new model of the blood flow rate has been developed. The approach is based on the principle of time-temperature superposition widely used in chemical physics and polymer rheology. For the blood perfusion, this idea is valid under the following assumptions: (I) the structure of a system does not experience qualitative changes during the treatment, and (II) the blood flow variation is predominantly controlled by a single mechanism. Numerous experimental data on changes in the blood flow under isothermal conditions have been used to derive a mathematical model for the blood flow rate variation in time during heating. Computer modelling of heat transfer processes performed on the basis of the developed model have revealed the influence of the heating regime on the temperature evolution in the malignant and normal tissues. The results obtained explain a great number of effects observed experimentally in hyperthermia, e.g. complicated evolution of temperature field under constant?power microwave heating, a higher temperature of malignant tissue than that of normal tissue, etc.

Key words:

blood flow, hyperthermia, heat transfer, computer simulation, polymer rheology, microwave heating.

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7.

CHEBYSHEV APPROXIMATION FOR HEAT TRANSFER FROM A
SEMI-INFINITELY LARGE POROUS PLATE IN A VISCOELASTIC FLUID

M.A. MANSOUR, H.M. EL-HAWARY

Mathematics Department, Assiut University
Assiut, EGYPT

R.S.R. GORLA
Department of Mechanical Engineering
Cleveland State University, Cleveland
Ohio 44115, USA

     An analysis is presented based upon the Chebyshev approximations for the boundary layer flow of a viscoelastic fluid over a porous plate. The technique reduces the problem to a system of non-linear equations in the highest-order derivatives which were solved by Newton's iterations.

Key words:

Chebyshev approximation, heat transfer, viscoelastic fluids.

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8.

CALCULATION OF THE RESTRAINING FORCE
FOR THE DRAWBEAD IN THE STAMPING PROCESS

Fuh-Kuo CHEN, Pao-Ching TSENG

Department of Mechanical Engineering
National Taiwan University
Taipei, Taiwan, R.O.C.

     A theoretical model based on the energy method was developed in the present study to derive a closed-form solution for the calculation of the restraining force produced by drawbeads used in a stamping process. In this model, the deformation of the sheet-metal drawn over a drawbead is characterized by bending, sliding and unbending processes. In order to include the friction effect in the calculations, a simple friction model was also proposed in the present study. Under the frictionless condition, the theoretical model slightly overestimates the restraining force when compared with that obtained from the finite element simulations, but renders the calculated values in better agreement with the experimental data. For the frictional case, the calculated values agree reasonably well with the finite element results. The proposed model is therefore justified.

Key words:

drawbead restraining force, energy method, plastic energy dissipation, finite element method.

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9.

ANALYSIS OF THE GAS-SOLID FLOW IN A RISER REACTOR

Andrzej KMIE∆

Institute of Chemical Engineering and Heating Equipment
of Technical University of Wroc≥aw, POLAND

     Investigations of aerodynamics of gas-solid flow in riser reactors designed for coal pyrolysis or for catalytic cracking higher boiling olefins and paraffin in semi-industrial scale have been carried out. A theoretical model based on differential equations for momentum balance of the gas-solid mixture, momentum balance of the solid phase and continuity equations for both the gas and the solid phase has been proposed. This method of description of gas-solids flow follows the approach of Arastoopour and Gidaspow but takes into account the solid-wall friction and stream expansion as it was done by Kmieś and Leschonski for injectors. Integration of differential equations has been performed by Gear's method. The effect of different empirical correlations for the solid-wall friction factor has been shown. Distributions, resulting from the model, for pressure, gas velocity, particle velocity, voidage and residence time of particle along the axis of apparatus have been presented.

Key words:

riser reactor, gas-solid flow, aerodynamics.

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