
Archive issue  vol.1 No.4
1.
A NUMERICAL STUDY OF MAGNETIC EFFECTS
ON PERISTALTIC FLOWS
B.V.Rathish Kumar
Department of Mathematics
IIT, Kanpur208016, U.P., INDIA
K.B.Naidu
Department of Mathematics
S.S.S.I.H.L., Prasanthinilayam, INDIA
The 'psi''omega' form of modified NavierStokes (NS) equations are solved numerically
for a two dimensional peristaltic flow under the influence of transverse
magnetic field. A simple nonlinear and noniterative streamline quadrature
upwinding 'psi''omega' finite element method (FEM) is employed in the flow analysis.
The velocity, pressure and stress fields of various peristaltic flows under
the influence of transverse magnetic fields are obtained. Effects of the
magnetic field are brought out by comparing these results with those of the
peristaltic flow free from the influence of magnetic field. Under the
influence of magnetic field velocities near the central axis decrease while
those near the wall tend to increase, streamlines shift downwards, wall
pressure distribution becomes antisymmetric and favours mixing and transporting
of the fluid, and wall shear stress decreases considerably.
 Key words: 
peristalsis, magnetohydrodynamics, finite element analysis, streamfunction, vorticity, physiological fluid. 
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2.
EXAMINING THE RATIO OF HYDRODYNAMIC RADIUS
TO THE RADIUS OF GYRATION OF FRACTAL AGGREGATES
Charles C.K. CHOU, ChungTe LEE
Graduate Institute of Environmental Engineering
National Central University, Chungli 32054, Taiwan, R.O.C.
Aerosol aggregates with ramified or netlike structure are usually found in the atmosphere. However, a comprehensive understanding of the hydrodynamic behavior of the aggregates has not been well established. In this study, collapsed silver aggregates with fractal dimension (D_{f}) ranging from 2.6 to 2.9 were generated by controlling the degrees of collapse. The ratio of hydrodynamic radius (R_{h}) to the radius of gyration (R_{g}) of the aggregates was calculated from the experimental measurements. It is shown that the ratio of R_{h}/R_{g} reaches an approximately constant value of 1.05 for aggregates with fractal dimension in this range.
 Key words: 
fractal aggregates, ultrafine particles, hydrodynamic radius, radius of gyration. 
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3.
BASIC RESEARCH ON OSCILLATING PLUG FLOW OF MAGNETIC FLUID
Kunio SHIMADA, Makio IWABUCHI, Kenichi OKUI
Department of Mechanical Systems Engineering
Toyama Univ., 3190 Gofuku, Toyama 930, JAPAN
Sinichi KAMIYAMA
Inst. of Fluid Science, Tohoku Univ.
211 Katahira, Aobaku, Sendai 98077, JAPAN
Basic research on oscillating plug flow of a magnetic fluid at low frequency is made as one of engineering applications for a micro sensing actuator. Magnetic and temperature fields have been applied to the device of the actuator. The magnetization of the magnetic fluid depends strongly on the temperature. At a low frequency range the amplitude of the oscillating plug flow is controlled more effectively by using temperature change of the magnetic fluid. The dynamic characteristics of the magnetic fluid actuator, especially the frequency response curve of amplitude, is investigated theoretically taking into account aggregation of particles. The basic experiment is conducted using a simple experimental apparatus for oscillating plug flow at low frequency. It follows from the theoretical and experimental results that the particle aggregates play an important role in the dynamic characteristics of the actuator.
 Key words: 
magnetic fluid, agregation, actutator, magnetic field, oscillating flow, temperature difference. 
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4.
MASS TRANSPORT IN A BRANCHING CHANNEL:
A NUMERICAL STUDY
Huaxiong HUANG
Department of Mathematics and Statistics
Simon Fraser University, Burnaby
B.C., V5A 1S6 CANADA
Brian R. SEYMOUR
Institute of Applied Mathematics
The University of British Columbia
Vancouver, B.C., V6T 1Z2, CANADA
Mass transport between the arterial wall and blood is believed to play an
important role in the initiation of atherosclerosis. Arterial branches are found
to be one of the most common sites for the occurrence of the disease. This paper
investigates the mass transport rate across the arterial wall using a simplified
twodimensional model of a symmetrically branched channel. It is found that the
mass transport rate is greatly reduced on the side wall of the branch where the
shear rate is low. The dependence of the mass transport rate on the area ratio
of the branching channel, as well as the branching angle, Reynolds and Schmidt
numbers, is also investigated.
 Key words: 
arterial wall, blood flow, branching channel, mass transport, numerical study. 
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5.
THE EFFECT OF SEVERAL FACTORS
OF THERMOHYDRODYNAMIC CHARACTERISTICS
ON ENERGY CONVERSION SYSTEM
WITH MAGNETIC FLUID
Kunio SHIMADA, Makio IWABUCHI, Kenichi OKUI
Dept. of Mechanical Systems Engineering
Toyama University
3190 Gofuku, Toyama 930, JAPAN
Shinichi KAMIYAMA
Inst. of Fluid Science, Tohoku Univ.
211 Katahira, Aobaku, Sendai 98077, JAPAN
Basic research is made on the effect of flow rate, nonuniform magnetic and
temperature fields on thermohydrodynamic characteristics of energy conversion
system by using magnetic fluid whose magnetic properties are susceptible to
temperature in applying magnetic field. Experimental study is conducted for
two cases of open and closed test loops. The experimental data of pressure
difference are compared with the theoretical results taking into account the
particles aggregation of the magnetic fluid in the applied magnetic field region.
The effects of flow rate, the amplitude and the direction of the magnetic field
and temperature difference on the pressure difference are clarified in relation
to the increment of apparent viscosity of the magnetic fluid by application of
magnetic field.
 Key words: 
magnetic fluid, aggregation, energy conversion system, magnetic field, flow rate, temperature difference. 
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6.
MAGNETOHYDRODYNAMIC FREE CONVECTION
ALONG A VERTICAL WAVY SURFACE
M.A. HOSSAIN, K.C. ALAM
Department of Mathematics, University of Dhaka
Dhaka 1000, BANGLADESH
I . POP
Faculty of Mathematics, University of Cluj
R3400 Cluj,CP 253, ROMANIA
The free convection boundary layer flow of a viscous, incompressible and
electrically conducting fluid along an isothermal vertical wavy surface in the
presence of a transverse magnetic field is discussed. A sinusoidal surface is
used to elucidate the effects of the magnetic field and the amplitude of the
wavy surface on the velocity and temperature fields as well as on the local
rate of heat tran{fer. The results are shown graphically for different values
of the magnetic field parameter M, amplitude of the wavy surface a, and the
Prandtl number Pr.
 Key words: 
magnetohydrodynamic, free convection, wavy surface. 
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7.
STABILITY OF THE COUETTE FLOW
OF VISCOELASTIC LIQUIDS
Marek JASTRZĘBSKI, Stanisław WROŃSKI
Instiute of Chemical and Process Engeering
Warsaw Technical University
ul.Waryńskiego 1, 00645 Warsaw, POLAND
The linear stabiliy of the Couette flow of viscoelastic liquid in an annular
gap is analysed theoretically, using the viscometric CriminaleEricksenFilbey
equation. The stability limit is discussed with reference to the viscometric
functions: viscosity, primary and secondary normal stress difference coefficients.
The form of the secondary normal stress difference function has a considerable
influence on the stability limit. The resuls of this work are in good agreement
with the theoretical predictions for the EdwardDoi and generalized Maxwell models.
 Key words: 
Couette flow, viscoelastic liquids, stability. 
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8.
INERTIA EFFECT IN THE LAMINAR FLOW
OF AN INCOMPRESSIBLE FLUID BETWEEN
ROTATING SURFACES OF REVOLUTION
Edward WALICKI, Anna WALICKA
Tehnical University of Zielona Góra,
Department of Mechanics,
65042 Zielona Góra, ul.Szafrana 2, POLAND
Laminar flow of an incompressible Newtonian fluid is considered in a narrow
space between two surfaces of revolution rotating, with generally different angular
velocities, about a common axis of symmetry. The problem statement for two classes
of throughflow, with full and rotational inertia, is formulated. Based on a
firstorder perturbation solution in the modified Reynolds number an analysis is
presented to determine the effect of the fluid film inertial forces on the dynamic
properties of a flow field. The results are presented for the velocity components
and the pressure distribution for typical shapes of surfaces as two disks and two
spherical surfaces.
 Key words: 
laminar flow, incompressible fluid, narrow space, surfaces of revolution, perturbation solution. 
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9.
HEAT TRANSFER FOR NONNEWTONIAN FLUIDS
FLOWING THROUGH AN ANNULAR SPACE COMPARISON
FOR DIFFERENT ASPECT RATIOS
M.NAIMI, M.LEBOUCHÉ, R.DEVIENNE
Lemta, CNRS URA 875 ET Université Poincaré
2, Avenue de la Foręt de Haye, BP 160
54504 VandoeuvrelčsNancy Cedex  FRANCE
This work discusses heat transfer for pseudoplastic and yield fluids. The
tested geometry consists of two coaxial cylinders, the outer one being subject
to a constant heat flux density, the inner core being able to rotate around its
axis. Semi empiricalcorrelations are proposed so as to predict the intensity of
heat transfer for these particular fluids. Moreover, we compare the obtained results
with the previous ones concerning a smilar measuring cell with a lower aspect ratio
and also with those relative to a real scraped surface heat exchanger, the dimensions
of which being exactly the ones of our device.
 Key words: 
pseudoplastic, yield fluids, heat transfer, annular space. 
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