Begell House Inc.
International Journal of Fluid Mechanics Research
FMR
2152-5102
44
1
2017
MAGNETOHYDRODYNAMIC FLOW AND HEAT TRANSFER TO SISKO NANOFLUID OVER A WEDGE
1-13
10.1615/InterJFluidMechRes.2017015861
Madhu
Macha
Kuvempu University
Cherlacola Srinivas
Reddy
Government Degree College, Mulugu, Telangana, 506343, India
Naikoti
Kishan
Osmania University, Hyderabad, India
Brownian motion
nanofluid
thermophoresis
Sisko fluid
wedge
This work investigates the magnetohydrodynamic boundary layer flow of Sisko nanofluid flow over a wedge. Our
nanofluid model incorporates the influences of thermophoresis and Brownian motion. Using a suitable similarity transformation, the governing nonlinear partial differential equations for the modelling of boundary layer flow are reduced to coupled nonlinear ordinary differential equation. The resulting ordinary differential equations are success-fully solved numerically with the help of the variational finite element method. To validate the present investigation, the obtained numerical results are compared to available results in the literature for some special cases and found to be in good agreement. The effects of the flow-controlling parameters on velocity, temperature, and nanoparticle volume fraction profiles are investigated through graphs. Numerical results of the local skin-friction coefficient and local Nusselt number are presented for several sets of values of physical parameters, and the salient features are discussed in detail. With the rise of the thermophoresis parameter, both the fluid temperature and nanoparticle volume fraction increase. It is found that the nanoparticle volume fraction decreases as the Brownian motion increases. Increasing Sisko fluid parameter decreases the velocity profiles whereas increases the temperature and nanoparticle volume fraction profiles.
STEADY MHD MASS TRANSFER FLOW IN PRESENCE OF HEAT SINK AND CHEMICAL REACTION
15-39
10.1615/InterJFluidMechRes.2017014119
Nazibuddin
Ahmed
Department of Mathematics, Gauhati University, Guwahati-781014, Assam, India
suction
free convection
viscous
incompressible
electrically conducting
The problem of a free convective MHD mass transfer flow past a semi-infinite vertical porous plate in the presence of
a heat-absorbing sink and homogeneous chemical reaction is studied. A magnetic field of uniform intensity is assumed
to be applied normal to the plate. The differential equations governing the flow are solved analytically by adopting an asymptotic series expansion for two cases: (i) small suction and (ii) large suction. The effects of different physical parameters on the flow and transport characteristics are given. One of the results of the present work for a special case has been compared to some already published work, and it is seen that both results are in excellent agreement.
TWO-PHASE FLOW FIELD IN A CYLINDRICAL HYDROCYCLONE WITH TANGENTIAL DISCHARGE
41-64
10.1615/InterJFluidMechRes.2017016140
Marzio
Piller
Department of Engineering and Architecture, University of Trieste, via A. Valerio 10, 34127
Trieste (TS), Italy
Jure
Mencinger
Department of Mechanical Engineering, University of Ljubljana, Ljubljana, 1000, Askrceva 6,
Slovenia
Gianni
Schena
Department of Engineering and Architecture, University of Trieste, via A. Valerio 10, 34127
Trieste (TS), Italy
Girolamo
Belardi
Istituto di Geologia Ambientale e Geoingegneria, Consiglio Nazionale delle Ricerche,
Monterotondo (RM), 00015, Italy
CFD
hydrodynamics
two-phase flow
DynaWhirlpool
The two-phase, air-water flow pattern in a DynaWhirlpool-type centrifugal separator is investigated using time-dependent, three-dimensional numerical simulation. The air-water interface is captured by the volume-of-fluid approach, while the unresolved turbulence fluctuations are modeled via a second-order differential-stress turbulence
model. The methodology is validated with available laser-Doppler data acquired on a similar separation device. The
velocity field within the cyclone is thoroughly characterized for a single operating condition, revealing the presence of a stable air core that flows axially faster than the surrounding water.
MODELING OF ELECTROSTATIC PRECIPITATOR AND STUDY OF PARTICLE COLLECTION
65-77
10.1615/InterJFluidMechRes.2017016367
Xiaoying
Zhou
Faculty of Mechanical Engineering & Automation, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018, China
Xiaoping
Chen
Faculty of Mechanical Engineering & Automation, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018, China
Hua-Shu
Dou
Faculty of Mechanical Engineering & Automation, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018, China
electrostatic precipitator
electric field
two-phase flow
numerical simulation
separation efficiency
A 3D numerical model based on the finite volume method is developed to simulate the entire precipitation process
inside an electrostatic precipitator (ESP). The complex coupled phenomena among the electric field, turbulent flow
field, particle charging process, and particle motion are taken into consideration for the full analysis of an electrostatic precipitator. The effect of electrohydrodynamics flow is considered for the accuracy of computation. The electric field is determined by the Poisson equation and the current continuity equation using the Kaptzov hypothesis. The discrete phase model is adopted to describe the particle motion, and the particle charge is calculated by the integration of the charging rate equation. It is found that the model can well simulate the inner characteristics and particle collection of ESP. The results show that the collection efficiency increases with the applied voltage, while the increasing inlet velocity
makes the collection process worse. It is also found that particles get most of their charges rapidly in the vicinity of the first corona electrode.
ASSESSMENT OF ACCUMULATION RATE OF LDL SPECIES IN ARTERIAL WALL LAYERS UNDER HYPERTENSION AND HYPERLIPIDEMIA CONDITIONS
79-92
10.1615/InterJFluidMechRes.2017016597
Somnath
Santra
Department of Mechanical Engineering, Indian Institute of Engineering Science and
Technology, Shibpur, Howrah - 711103, West Bengal, India
Dipak Kumar
Mandal
Deptartment of Mechanical Engineering, College of Engineering & Management, Kolaghat,
P.O: K.T.P.P. Township, Midnapore (E) - 721171, West Bengal, India
Somnath
Chakrabarti
Department of Mechanical Engineering, Indian Institute of Engineering Science and Technology Shibpur, Howrah, 711103, West Bengal, India
non-Newtonian fluid
hypertension
hyperlipidemia
intima
media
accumulation rate
atherosclerosis
In this study, a numerical model has been developed for implementing the convective and diffusive transport of LDL
cholesterol in multilayered arterial wall. A new conceptual approach has also been done in order to estimate the LDL
deposition rate in arterial layers under hyper-tension and hyper-lipidemia conditions considering the non-Newtonian
nature of blood. The arterial wall layers viz. endothelium, intima, internal elastic lamina (IEL) and media are assumed
to be homogeneous porous media. The Navier-Stokes equation and Darcy's equation have been used for representing
the fluid flow in the lumen and the arterial wall, respectively. The mass transport in the lumen has been modeled through the convection-diffusion equation, whereas volume-averaged convection-diffusion-reaction equation has been used for simulating the mass transport through porous layers. This paper shows that the rate of accumulation is higher in intima layer than the media layer and also pointed out that the intima layer is a possible layer of initiation of the disease and that the endothelium provides a maximum barrier to solute flow across it. Thus, any denudation that
occurred in endothelium may enhance the possibility of the formation of the disease. Finally, the paper shows that
among the considered clinical parameters (hypertension and hyperlipidemia), hypertension is more vulnerable to the
possible occurrence of the disease.