scholarly journals Boundary Layer Flow, Heat and Mass Transfer of Cu-Water Nanofluid over a Moving Plate with Soret and Dufour Effects: Stability Analysis

Author(s):  
Najwa Najib ◽  
Norfifah Bachok

Our main focus in this paper is to investigate the effects of Soret and Dufour known as thermodiffusion and diffusion-thermo on moving plate in copper water nanofluid. The set of partial differential equations are converted into set of ordinary differential equations using the appropriate similarity variables before being solved numerically using bvp4c code in Matlab software. The results of heat and mass transfer, temperature and concentration profiles on Soret as well as Dufour effects are presented graphically. Soret effect increases the heat transfer rate at the surface while Dufour effect decreases the mass transfer rate at the surface. Since the solutions exist in dual, we carry out the stability solutions to determine which solution is stable and hence the physical meaning is realized physically.

2019 ◽  
Vol 35 (5) ◽  
pp. 657-675 ◽  
Author(s):  
Odelu Ojjela ◽  
Adigoppula Raju ◽  
N. Naresh Kumar

ABSTRACTThe present article deals with the influence of the induced magnetic field on an unsteady two dimensional incompressible free convective chemically reacting slip flow of Jeffrey fluid between two parallel plates under the influence of the thermal radiation, Soret and Dufour. It is assumed that the flow is generated due to periodic suction/injection and the non-uniform temperature and concentrations are varying periodically with time at the plates. The governing partial differential equations are reduced into nonlinear ordinary differential equations by using similarity transformations and solved by shooting method along with Rung-Kutta 4th order scheme. The results are analyzed for various flows, heat and mass transfer characteristics with respect to various prominent parameters such as the ratio of relaxation to retardation times, Deborah number, magnetic Reynold’s number, Strommer’s number, radiation parameter, chemical reaction parameter, Soret and Dufour numbers in details through graphs and tables. It is observed that the temperature of the fluid is enhanced with Soret and Dufour whereas the concentration is decreased. Also the mass transfer rate of the fluid is enhanced with Strommer’s number, whereas the heat transfer rate decreases with increasing of the Jeffery fluid parameter. The present results have good agreement with published work for Newtonian case.


2019 ◽  
Vol 8 (1) ◽  
pp. 470-485 ◽  
Author(s):  
V. Ramachandra Prasad ◽  
S. Abdul gaffar ◽  
B. Rushi Kumar

Abstract This article aims to study theoretically the combined magneto hydrodynamic flows of casson viscoplastic nanofluid from a horizontal isothermal circular cylinder in non-Darcy porous medium. The impacts of Brownian motion and thermophoresis are consolidated and studied. The governing partial differential equations are converted into nonlinear ordinary differential equations using suitable non-similarity transformation and are solved numerically using Keller-Box finite difference technique. The numerical method is validated with previous published work and the results are found to be in excellent agreement. Numerical results for velocity, temperature, concentration along with skin friction coefficient, heat and mass transfer rate are discussed for various values of physical parameters. It is observed that velocity, heat and mass transfer rate are increased with increasing casson fluid parameter whereas temperature, concentration and skin friction are decreased. Velocity is reduced with increasing Forchheimer parameter whereas temperature and nano-particle concentration are both enhanced. An increase in magnetic parameter is seen to increase temperature and concentration whereas velocity, skin friction heat and mass transfer rate are decreased. The present model finds applications in electric-conductive nano-materials of potential use in aviation and different enterprises, energy systems and thermal enhancement of industrial flow processes.


2014 ◽  
Vol 71 (1) ◽  
Author(s):  
Noraihan Afiqah Rawi ◽  
Abdul Rahman Mohd Kasim ◽  
Mukheta Isa ◽  
Sharidan Shafie

This paper studies unsteady mixed convection boundary layer flow of heat and mass transfer past an inclined stretching sheet associated with the effect of periodical gravity modulation or g-jitter. The temperature and concentration are assumed to vary linearly with x, where x is the distance along the plate. The governing partial differential equations are transformed to a set of coupled ordinary differential equations using non-similarity transformation and solved numerically by Keller-box method. Numerical results for velocity, temperature and concentration profiles as well as skin friction, Nusselt number and Sherwood number are presented and analyzed for different values of inclination angle parameter.


2018 ◽  
Vol 8 (4) ◽  
pp. 3223-3227
Author(s):  
A. Latreche ◽  
M. Djezzar

In this study, two dimensional natural convection heat and mass transfer generated in an inclined rectangular porous cavity filled with Newtonian fluid has been investigated numerically. The cavity is heated and cooled along horizontal walls while the solutal gradient is imposed horizontally. The physical model for the momentum conservation equation makes use of the Darcy model, and the set of coupled equations is solved using a finite volume approach. The successive-under-relaxation (SUR) method is used in the solution of the stream function equation. The results are presented graphically in terms of streamlines, isotherms and iso-concentrations. The heat and mass transfer rate in the cavity is measured in terms of the average Nusselt and Sherwood numbers for various non-dimensional parameters.


2016 ◽  
Vol 78 (5-5) ◽  
Author(s):  
Dewanto Harjunowibowo ◽  
Dina Nur Adilah ◽  
Dwi Teguh Rahardjo ◽  
Danar S. Wijayanto ◽  
Fredy Surahmanto ◽  
...  

The density of adsorbent bed significantly contributed to solar cooling performance (COP). The density determines how well the heat and mass transfer are. Besides that, the COP is also determined by ambient temperature. This research aims to investigate the affect of temperature of a connecting pipe, as a representative of different ambient temperature against a solar cooling machine performance. The experiment will show in what condition a solar cooling is going to have a better cooling result. The data used in this case was taken experimentally and conducted using a solar cooling machine equipped with temperature measurement units such as thermocouple logger. For cold ambient temperature, in adsorption process, refrigerant vapour flows to the generator through the connecting pipe cooled by water and kept steady. The results show that the COP, heat and mass transfer of adsorbent bed of the system in the adsorption process on a warm condition are better than in a cold environment. In the warm condition the COP system is 0.24, the heat transfer rate is 0.06 °C/minute, and the mass transfer rate is 1.09 ml/minute. Whereas, in the cold condition the COP system is 0.23, the heat transfer rate is 0.05 °C/minute, and the mass transfer rate is 1.04 ml/minute. 


2013 ◽  
Vol 3 (4) ◽  
Author(s):  
Darbhasayanam Srinivasacharya ◽  
Mendu Upendar

AbstractThis paper analyzes the flow, heat and mass transfer characteristics of the mixed convection on a vertical plate in a micropolar fluid in the presence of Soret and Dufour effects. A uniform magnetic field of magnitude is applied normal to the plate. The governing nonlinear partial differential equations are transformed into a system of coupled nonlinear ordinary differential equations using similarity transformations and then solved numerically using the Keller-box method. The numerical results are compared and found to be in good agreement with previously published results as special cases of the present investigation. The rate of heat and mass transfer at the plate are presented graphically for various values of coupling number, magnetic parameter, Prandtl number, Schmidt number, Dufour and Soret numbers. In addition, the skin-friction coefficient, the wall couple stress are shown in a tabular form.


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