RADIATION EFFECTS ON AN UNSTEADY NATURAL CONVECTIVE FLOW OF A NANOFLUID PAST AN INFINITE VERTICAL PLATE

NANO ◽  
2013 ◽  
Vol 08 (01) ◽  
pp. 1350001 ◽  
Author(s):  
P. LOGANATHAN ◽  
P. NIRMAL CHAND ◽  
P. GANESAN
Keyword(s):  
Heat Transfer ◽  
Skin Friction ◽  
Convective Flow ◽  
Radiation Effects ◽  
Vertical Plate ◽  
Volume Fraction ◽  
Fluid Velocity ◽  
Skin Friction Coefficient ◽  
Laplace Transform Technique ◽  
Infinite Vertical Plate

An exact analysis is carried out to study the radiation effects on an unsteady natural convective flow of a nanofluid past an impulsively started infinite vertical plate. The nanofluids containing nanoparticles of aluminium oxide, copper, titanium oxide and silver with nanoparticle volume fraction range less than or equal to 0.04 are considered. The partial differential equations governing the flow are solved by Laplace transform technique. The influence of various parameters on velocity and temperature profiles, as well as Nusselt number and skin-friction coefficient, are examined and presented graphically. An increase in radiation parameter and time leads to fall in temperature of the fluid. The presence of nanoparticles and thermal radiation increases the rate of heat transfer and skin friction. The effect of heat transfer is found to be more pronounced in silver water nanofluid than in the other nanofluids. It is observed that the fluid velocity increases with an increase in Grashof number and time. Excellent validation of the present results is achieved with existing results in the literature.

Soret and Radiation Effects on Transient MHD Free Convection From an Impulsively Started Infinite Vertical Plate

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
N. Ahmed
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Free Convection ◽  
Thermal Radiation ◽  
Skin Friction ◽  
Vertical Plate ◽  
Soret Effect ◽  
Viscous Drag ◽  
Laplace Transform Technique ◽  
Infinite Vertical Plate

An exact solution to the problem of MHD transient free convection and mass transfer flow of a viscous, incompressible, and electrically conducting fluid past a suddenly started infinite vertical plate taking into account the thermal diffusion as well as the thermal radiation is presented. Assuming the medium to be nonscattered and the fluid to be nongray, emitting–absorbing, and optically thin radiation limit properties, the equations governing the flow and heat and mass transfer are solved by Laplace transform technique. The expressions for the velocity field, the concentration field, the skin friction at the plate in the direction of the flow, and the coefficient of heat transfer and mass transfer from the plate to the fluid have been obtained, and their numerical values for different values of the physical parameters involved in the problem have been demonstrated in graphs and tables, and these are physically interpreted. It is found that the thermal radiation retards the fluid flow whereas the Soret effect accelerates the flow. The viscous drag on the plate is increased under the Soret and magnetic field effects whereas the thermal radiation reduces the skin friction. Further, the rate of heat transfer at the plate increases under thermal radiation effect. Also, in the presence of radiation, the Soret effect results in a steady increase in the mass flux from the fluid to the plate.

Heat Transfer Analysis of a Williamson Micropolar Nanofluid with Different Flow Controls

2018 ◽  
Vol 35 (3) ◽  
pp. 381-394 ◽  
Author(s):  
M. Muthtamilselvan ◽  
E. Ramya ◽  
D. H. Doh ◽  
G. R. Cho
Keyword(s):  
Heat Transfer ◽  
Differential Equations ◽  
Skin Friction ◽  
Radiation Effects ◽  
Volume Fraction ◽  
Skin Friction Coefficient ◽  
Heat Transfer Analysis ◽  
Physical Parameters ◽  
Linear Ordinary Differential Equations ◽  
Micropolar Nanofluid

ABSTRACTThe present model is devoted for the steady stagnation point flow of a Williamson micropolar nanofluid with magneto-hydrodynamics and thermal radiation effects passed over a horizontal porous stretching sheet. The fluid is considered to be gray, absorbing-emitting but non-scattering medium. The Cogley-Vincent-Gilles formulation is adopted to simulate the radiation component of heat transfer. By applying similarity analysis, the governing partial differential equations are transformed into a set of non-linear ordinary differential equations and they are solved by using the bvp4c package in MATLAB. Numerical computations are carried out for various values of the physical parameters. The effects of momentum, microrotation, temperature and nanoparticle volume fraction profiles together with the reduced skin friction coefficient, reduced Nusselt number and reduced Sherwood number of both active and passive controls on the wall mass flux are graphically presented. The present results are compared with previously obtained solutions and they are in good agreement. Results show that the skin friction is increasing functions of the Williamson parameter in both stretching and shrinking surfaces.

scholarly journals Study of ramped temperature influence on MHD convective chemically reactive and absorbing fluid past an exponentially accelerated vertical porous plate

2018 ◽  
Vol 15 (2) ◽  
pp. 107-125
Author(s):  
M C Raju ◽  
S Harinath Reddy ◽  
Dr. E. Keshava Reddy
Keyword(s):  
Friction Coefficient ◽  
Skin Friction ◽  
Vertical Plate ◽  
Fluid Velocity ◽  
Porous Plate ◽  
Skin Friction Coefficient ◽  
Physical Parameters ◽  
Governing Equations ◽  
Laplace Transform Technique ◽  
The Impact

A systematic study has been performed on MHD convective chemically reactive and absorbing fluid along an exponentially accelerated vertical plate with the impact of Hall current by considering ramped temperature. Laplace transform technique is applied to obtain exact solutions of the non-dimensional governing equations for fluid velocity, temperature and concentration. Based on these solutions, the expressions for skin friction coefficient, Nusselt number and Sherwood number are also derived. The consequences of diverse physical parameters on flow quantities are examined thoroughly with graphical representations. The numerical values for skin friction coefficient, rate of heat transfer and rate of mass transfer are recorded and analyzed.

scholarly journals Stagnation-point flow past a shrinking sheet in a nanofluid

Open Physics ◽  
2011 ◽  
Vol 9 (5) ◽  
Author(s):  
Roslinda Nazar ◽  
Mihaela Jaradat ◽  
Norihan Arifin ◽  
Ioan Pop
Keyword(s):  
Heat Transfer ◽  
Friction Coefficient ◽  
Nonlinear System ◽  
Differential Equations ◽  
Skin Friction ◽  
Stagnation Point ◽  
Volume Fraction ◽  
Skin Friction Coefficient ◽  
Stagnation Point Flow ◽  
Shrinking Sheet

AbstractIn this paper, the stagnation-point flow and heat transfer towards a shrinking sheet in a nanofluid is considered. The nonlinear system of coupled partial differential equations was transformed and reduced to a nonlinear system of coupled ordinary differential equations, which was solved numerically using the shooting method. Numerical results were obtained for the skin friction coefficient, the local Nusselt number as well as the velocity and temperature profiles for some values of the governing parameters, namely the nanoparticle volume fraction φ, the shrinking parameter λand the Prandtl number Pr. Three different types of nanoparticles are considered, namely Cu, Al2O3 and TiO2. It was found that nanoparticles of low thermal conductivity, TiO2, have better enhancement on heat transfer compared to nanoparticles Al2O3 and Cu. For a particular nanoparticle, increasing the volume fraction φ results in an increase of the skin friction coefficient and the heat transfer rate at the surface. It is also found that solutions do not exist for larger shrinking rates and dual solutions exist when λ < −1.0.

scholarly journals Heat and mass transfer effects on moving vertical plate in the presence of thermal radiation

2004 ◽  
Vol 31 (1) ◽  
pp. 35-46 ◽  
Author(s):  
R. Muthucumaraswamy ◽  
Kumar Senthil
Keyword(s):  
Thermal Radiation ◽  
Radiation Effects ◽  
Vertical Plate ◽  
Variable Temperature ◽  
Radiation Parameter ◽  
Plate Temperature ◽  
Grashof Number ◽  
Laplace Transform Technique ◽  
The Laplace Transform ◽  
Infinite Vertical Plate

Thermal radiation effects on moving infinite vertical plate in the presence variable temperature and mass diffusion is considered. The fluid considered here is a gray, absorbing-emitting radiation but a non-scattering medium. The plate temperature and the concentration level near the plate are raised linearly with time. The dimensionless governing equations are solved using the Laplace-transform technique. The velocity and skin-friction are studied for different parameters like thermal Grashof number, mass Grashof number, time and radiation parameter. It is observed that the velocity slightly decreases with increasing value of the radiation parameter.

HEAT GENERATION AND ABSORPTION IN MHD FLOW OF CASSON FLUID PAST A STRETCHING WEDGE WITH VISCOUS DISSIPATION AND NEWTONIAN HEATING

2018 ◽  
Vol 80 (3) ◽  
Author(s):  
Imran Ullah ◽  
Sharidan Shafie ◽  
Ilyas Khan
Keyword(s):  
Heat Transfer ◽  
Skin Friction ◽  
Heat Transfer Rate ◽  
Heat Generation ◽  
Transfer Rate ◽  
Fluid Velocity ◽  
Mhd Flow ◽  
Casson Fluid ◽  
Skin Friction Coefficient ◽  
Fluid Temperature

The dissipative flow of Casson fluid in the presence of heat generation and absorption is investigated. The flow is induced due to stretching wedge. The similarity transformations were used to to transformed the governing equations into ordinary differential equations. The transformed equations are solved numerically via Keller-box method. Numerical results for skin friction coefficient are compared and found in excellent agreement with published results. The effects of pertinent parameters on velocity and temperature profiles as well as skin friction and heat transfer rate are graphically displayed and analyzed. It is noticed that fluid velocity drops with the increase of Casson fluid and magnetic parameters when the wedge is stretching faster than free stream. It is also noted that the heat transfer rate at wedge surface reduces with the increase of Eckert number, whereas the reverse trend is noted in the case of Casson and radiation parameters. Moreover, with increasing of heat generation or absorption parameter the fluid temperature rises.

scholarly journals Duality Solutions in Hydromagnetic Flow of SWCNT-MWCNT/Water Hybrid Nanofluid over Vertical Moving Slender Needle

Mathematics ◽  
2021 ◽  
Vol 9 (22) ◽  
pp. 2927
Author(s):  
Nur Adilah Liyana Aladdin ◽  
Norfifah Bachok
Keyword(s):  
Heat Transfer ◽  
Differential Equation ◽  
Carbon Nanotube ◽  
Friction Coefficient ◽  
Mixed Convection ◽  
Skin Friction ◽  
Volume Fraction ◽  
Skin Friction Coefficient ◽  
Convection Boundary Layer ◽  
Hybrid Nanofluid

Recently, the topic of convection of heat transfer has created an interest among researchers because of its numerous applications in the daily life. The objective of this paper was to study theoretically the problem of mixed convection boundary layer flow and heat transfer of single-wall carbon nanotube (SWCNT) and multi-wall carbon nanotube (MWCNT) in presence of hydromagnetic effects. The problem was initiated by formulating a mathematical model in partial differential equation (PDE) for the hybrid nanofluid flow with appropriate boundary conditions. The similarity equation was used to transform the PDE into an ordinary differential equation (ODE) and solved using bvp4c in MATLAB. The graphical results on variation of skin friction coefficient, , local Nusselt number, , shear stress, and local heat flux, with the effects of magnetic, size of needle, c, mixed convection parameter, and volume fraction of nanoparticles, were presented and discussed in detail. The study revealed that duality of solutions appears when the buoyance force is in opposing flow of the fluid motion, The presence of M in hybrid nanofluid reduced the skin friction coefficient and heat transfer. On the other hand, the and increased as different concentrations of and c were added. It gives an insight into the medical field, especially in treating cancer cells. By means, it reveals that CNTs hybrid nanofluid shows high potential in reaching the site of tumors faster compared with nanofluid. A stability analysis has to be carried out. It is noticed that the first solution was stable and physically realizable.

scholarly journals MHD free convective flow past an impulsively started vertical plate through a porous medium with radiative heat transfer and chemical reaction in a rotating system

2019 ◽  
Vol 15 (2) ◽  
pp. 237-242
Author(s):  
Uday Singh Rajput ◽  
Mohammad Shareef
Keyword(s):  
Porous Medium ◽  
Chemical Reaction ◽  
Convective Flow ◽  
Vertical Plate ◽  
Hall Current ◽  
Fluid Velocity ◽  
Rotating System ◽  
Free Convective Flow ◽  
Flow Past ◽  
Laplace Transform Technique

The effect of Hall current, radiation and chemical reaction on MHD free convective flow past an impulsively started vertical plate through a porous medium in a rotating system is considered. The analytical solutions of dimensionless governing equations are obtained by Laplace transform technique. The effects of various parameters on the fluid velocity, concentration and temperature distribution near the plate are analyzed and shown graphically. The numerical values of shear stress at the plate are shown in a table. It is observed that the fluid velocity near the plate is affected significantly by Hall current, radiation, chemical reaction and porous medium. The conclusion of study have applications in the field related to the solar physics dealing with the solar cycle, the sunspot development, the structure of rotating magnetic stars etc.

scholarly journals Unsteady Hydromagnetic Flow of Radiating Fluid Past a Convectively Heated Vertical Plate with the Navier Slip

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
O. D. Makinde ◽  
M. S. Tshehla
Keyword(s):  
Nusselt Number ◽  
Friction Coefficient ◽  
Skin Friction ◽  
Vertical Plate ◽  
Fluid Velocity ◽  
Nonlinear Partial Differential Equations ◽  
Skin Friction Coefficient ◽  
Newtonian Heating ◽  
Local Skin ◽  
Navier Slip

This paper investigates the unsteady hydromagnetic-free convection of an incompressible electrical conducting Boussinesq’s radiating fluid past a moving vertical plate in an optically thin environment with the Navier slip, viscous dissipation, and Ohmic and Newtonian heating. The nonlinear partial differential equations governing the transient problem are obtained and tackled numerically using a semidiscretization finite difference method coupled with Runge-Kutta Fehlberg integration technique. Numerical data for the local skin friction coefficient and the Nusselt number have been tabulated for various values of parametric conditions. Graphical results for the fluid velocity, temperature, skin friction, and the Nusselt number are presented and discussed. The results indicate that the skin friction coefficient decreases while the heat transfer rate at the plate surface increases as the slip parameter and Newtonian heating increase.

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