scholarly journals Impact of heat generation/absorption of magnetohydrodynamics Oldroyd-B fluid impinging on an inclined stretching sheet with radiation

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Fazle Mabood ◽  
Gabriella Bognár ◽  
Anum Shafiq
Keyword(s):  
Nusselt Number ◽  
Skin Friction ◽  
Heat Generation ◽  
Local Nusselt Number ◽  
Mhd Flow ◽  
Similarity Solutions ◽  
Deborah Number ◽  
Radiation Parameter ◽  
Local Skin ◽  
Local Skin Friction

Abstract In this paper, we have investigated thermally stratified MHD flow of an Oldroyd-B fluid over an inclined stretching surface in the presence of heat generation/absorption. Similarity solutions for the transformed governing equations are obtained. The reduced equations are solved numerically using the Runge–Kutta Fehlberg method with shooting technique. The influences of various involved parameters on velocity profiles, temperature profiles, local skin friction, and local Nusselt number are discussed. Numerical values of local skin friction and local Nusselt number are computed. The significant outcomes of the study are that the velocity decreases when the radiation parameter $$R_{d}$$ R d is increased while the temperature profile is increased for higher values of radiation parameter $$R_{d}$$ R d in case of opposing flow, moreover, growth in Deborah number $$\beta_{2}$$ β 2 enhance the velocity and momentum boundary layer. The heat transfer rate is decrease due to magnetic strength but increase with the increased values of Prandtl and Deborah numbers. The results of this model are closely matched with the outputs available in the literature.

scholarly journals Effects of Slip and Heat Generation/Absorption on MHD Mixed Convection Flow of a Micropolar Fluid over a Heated Stretching Surface

2010 ◽  
Vol 2010 ◽  
pp. 1-20 ◽  
Author(s):  
Mostafa Mahmoud ◽  
Shimaa Waheed
Keyword(s):  
Nusselt Number ◽  
Friction Coefficient ◽  
Mixed Convection ◽  
Skin Friction ◽  
Heat Generation ◽  
Local Nusselt Number ◽  
Skin Friction Coefficient ◽  
Convection Flow ◽  
Local Skin ◽  
Local Skin Friction

A theoretical analysis is performed to study the flow and heat transfer characteristics of magnetohydrodynamic mixed convection flow of a micropolar fluid past a stretching surface with slip velocity at the surface and heat generation (absorption). The transformed equations solved numerically using the Chebyshev spectral method. Numerical results for the velocity, the angular velocity, and the temperature for various values of different parameters are illustrated graphically. Also, the effects of various parameters on the local skin-friction coefficient and the local Nusselt number are given in tabular form and discussed. The results show that the mixed convection parameter has the effect of enhancing both the velocity and the local Nusselt number and suppressing both the local skin-friction coefficient and the temperature. It is found that local skin-friction coefficient increases while the local Nusselt number decreases as the magnetic parameter increases. The results show also that increasing the heat generation parameter leads to a rise in both the velocity and the temperature and a fall in the local skin-friction coefficient and the local Nusselt number. Furthermore, it is shown that the local skin-friction coefficient and the local Nusselt number decrease when the slip parameter increases.

Non-similar characteristics of mixed convective slip flow over a wedge with temperature-dependent thermo-physical properties

2019 ◽  
Vol 33 (36) ◽  
pp. 1950455
Author(s):  
Nepal Chandra Roy ◽  
Sudharonjon Roy ◽  
Naved Azum ◽  
Anish Khan ◽  
Abdullah M. Asiri ◽  
...  
Keyword(s):  
Nusselt Number ◽  
Friction Coefficient ◽  
Skin Friction ◽  
Sherwood Number ◽  
Local Nusselt Number ◽  
Slip Flow ◽  
Skin Friction Coefficient ◽  
Local Skin ◽  
Local Skin Friction ◽  
Local Sherwood Number

We examined heat and mass transfer characteristics of mixed convective slip flow over a wedge taking into account the effect of variable transport properties. Unlike other studies, we have utilized non-similar transformation to get the non-similar features of the mixed convective slip flow. For comparison, stream function formulation is used to reduce the governing equation into a convenient form for short- and long-time regimes. We have determined the series solutions by adopting the perturbation techniques. The agreement between the numerical and series solutions is found to be excellent. Numerical solutions reveal that the slip parameters augment the momentum, thermal and concentration boundary layers. The local skin friction coefficient, the local Nusselt number and the local Sherwood number are found to decrease for higher value of slip parameters. For the increasing value of the variable viscosity parameter, the velocity is stronger, but the temperature and concentration lessen. Contrary to this, this parameter diminishes the local skin friction coefficient, local Nusselt number and local Sherwood number. Due to the increase of mass diffusivity parameter, the velocity and concentration significantly increase whereas the temperature remains almost unaffected. Moreover, the mass diffusivity variation parameter leads to an increase in the local skin friction coefficient and local Nusselt number, but it reduces the local Sherwood number.

Computational Study of Three-Dimensional Stagnation Point Nanofluid Bioconvection Flow on a Moving Surface With Anisotropic Slip and Thermal Jump Effect

2016 ◽  
Vol 138 (10) ◽  
Author(s):  
M. J. Uddin ◽  
W. A. Khan ◽  
A. I. Md. Ismail ◽  
O. Anwar Bég
Keyword(s):  
Nusselt Number ◽  
Skin Friction ◽  
Stagnation Point ◽  
Local Nusselt Number ◽  
Local Density ◽  
Three Dimensional ◽  
Velocity Slip ◽  
Slip Parameter ◽  
Moving Surface ◽  
Local Skin

The effects of anisotropic slip and thermal jump on the three-dimensional stagnation point flow of nanofluid containing microorganisms from a moving surface have been investigated numerically. Anisotropic slip takes place on geometrically striated surfaces and superhydrophobic strips. Zero mass flux of nanoparticles at the surface is applied to achieve practically applicable results. Using appropriate similarity transformations, the transport equations are reduced to a system of nonlinear ordinary differential equations with coupled boundary conditions. Numerical solutions are reported by means of very efficient numerical method provided by the symbolic code Maple. The influences of the emerging parameters on the dimensionless velocity, temperature, nanoparticle volumetric fraction, density of motile microorganism profiles, as well as the local skin friction coefficient, the local Nusselt number, and the local density of the motile microorganisms are displayed graphically and illustrated in detail. The computations demonstrate that the skin friction along the x-axis is enhanced with the velocity slip parameter along the y-axis. The converse response is observed for the dimensionless skin friction along the y-axis. The heat transfer rate is increased with greater velocity slip effects but depressed with the thermal slip parameter. The local Nusselt number is increased with Prandtl number and decreased with the thermophoresis parameter. The local density for motile microorganisms is enhanced with velocity slip parameters and depressed with the bioconvection Lewis number, thermophoresis, and Péclet number. Numerical results are validated where possible with published results and excellent correlation is achieved.

Effects of Viscous Dissipation and Joule Heating on Natural Convection Flow of a Viscous Fluid from Heated Vertical Wavy Surface

2011 ◽  
Vol 66 (6-7) ◽  
pp. 427-440 ◽  
Author(s):  
Nasser S. Elgazery ◽  
Nader Y. Abd Elazem
Keyword(s):  
Nusselt Number ◽  
Natural Convection ◽  
Skin Friction ◽  
Viscous Dissipation ◽  
Joule Heating ◽  
Wavy Surface ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Local Skin ◽  
Local Skin Friction

A mathematical model will be analyzed in order to study the effects of viscous dissipation and Ohmic heating (Joule heating) on magnetohydrodynamic (MHD) natural convection flow of a temperature dependent viscosity from heated vertical wavy surface. The present physical problem is studied numerically by using the appropriate variables, which reduce the complex wavy surface into a flat one. An implicit marching Chebyshev collocation scheme is employed for the analysis. Numerical solutions are obtained for velocity, temperature, local skin friction, and Nusselt number for a selection of parameter sets consisting of Eckert number, Prandtl number, MHD variation, and amplitude-wavelength ratio parameter. Numerical results show that these parameters have significant influences on the velocity and the temperature profiles as well as for the local skin friction and Nusselt number

scholarly journals Natural convection on heat transfer flow of non-newtonian second grade fluid over horizontal circular cylinder with thermal radiation

2016 ◽  
Vol 13 (1) ◽  
pp. 63-78 ◽  
Author(s):  
V. Ramachandra Prasad ◽  
R. Bhuvanavijaya ◽  
Mallikarjuna Bandaru
Keyword(s):  
Nusselt Number ◽  
Flow Velocity ◽  
Skin Friction ◽  
Deborah Number ◽  
Second Grade ◽  
Temperature Profiles ◽  
Radiation Parameter ◽  
Second Grade Fluid ◽  
Grade Fluid ◽  
Horizontal Circular Cylinder

This article numerically studies for multi-physical transport of an optically-dense, free convective incompressible non-Newtonian second grade fluid past an isothermal, impermeable horizontal circular cylinder. The governing boundary layer equations for momentum and energy transport, which are parabolic in nature, have been reduced to non-similarity non-linear conservation equations using appropriate transformations and then solved numerically by employing with most validated, efficient implicit finite difference method with Keller box scheme. The numerical code is validated with previously existing results and found to be very good agreement. The results are reported graphically and in tabular form for various physical parameters; Deborah number, Prandtl number and thermal radiation on flow velocity and temperature profiles. Furthermore, the effects of these parameters on non dimensional wall shear stress (skin friction) and surface heat transfer rate (Nusselt number) are also investigated. Increasing the Deborah number reduces velocity profile, skin friction and Nusselt number where as it enhances the temperature profile. Increasing Prandtl number decelerates the flow velocity, temperature and skin friction but Nusselt number enhances considerably. Increase in radiation parameter retards the flow velocity, temperature profiles and skin friction. But Nusselt number enhances markedly with increase in radiation parameter. Applications of the model arise in polymer processing in chemical engineering, metallurgical material processing.

scholarly journals NUMERICAL SIMULATION OF ENTROPY GENERATION FOR CASSON FLUID FLOW THROUGH PERMEABLE WALLS AND CONVECTIVE HEATING WITH THERMAL RADIATION EFFECT

2020 ◽  
Vol 14 (2) ◽  
pp. 150-167
Author(s):  
Obalalu Adebowale Martins ◽  
Kazeem Issa ◽  
Abdulrazaq Abdulraheem ◽  
Ajala Olusegun Adebayo ◽  
Adeosun Adeshina Taofeeq ◽  
...  
Keyword(s):  
Nusselt Number ◽  
Fluid Flow ◽  
Thermal Radiation ◽  
Skin Friction ◽  
Entropy Generation ◽  
Casson Fluid ◽  
Radiation Parameter ◽  
Weighted Residual Method ◽  
Local Skin ◽  
Residual Method

In this work, the influence of entropy generation analysis for an electrically conducting Casson fluid flow with convective boundary conditions has been numerically studied. The governing equations are analyzed numerically using weighted residual methods. Subsequently, the residuals were minimized using two different approaches of weighted residual method namely collocation weighted residual method (CWRM) and Galerkin weighted residual method (GWRM) and computed numerically using MATHEMATICAL software. The impacts of governing parameters on Casson flow velocity, temperature profile, local skin friction, and Nusselt number were analysed. The obtained solutions were used to determine the heat transfer irreversibility and bejan number of the model. The results of the computation show that the effect of thermophysical properties such as thermal radiation parameter, suction/injection parameter, magnetic field parameter, radiation parameter, and Eckert number has a significant influence on Skin friction coefficient (Cf) and local Nusselt number (Nu) when compared to the Newtonian fluid. The findings from this study are relevant to advances in viscoelasticity and enhanced oil recovery.

scholarly journals Heat transfer analysis of the mixed convective flow of magnetohydrodynamic hybrid nanofluid past a stretching sheet with velocity and thermal slip conditions

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260854
Author(s):  
Muhammad Ramzan ◽  
Abdullah Dawar ◽  
Anwar Saeed ◽  
Poom Kumam ◽  
Wiboonsak Watthayu ◽  
...  
Keyword(s):  
Nusselt Number ◽  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Skin Friction ◽  
Heat Generation ◽  
Higher Order ◽  
Eckert Number ◽  
Hybrid Nanofluid ◽  
Radiation Parameter ◽  
Slip Conditions

The present study is related to the analytical investigation of the magnetohydrodynamic flow of Ag − MgO/ water hybrid nanoliquid with slip conditions via an extending surface. The thermal radiation and Joule heating effects are incorporated within the existing hybrid nanofluid model. The system of higher-order partial differential equations is converted to the nonlinear system of ordinary differential equations by interpreting the similarity transformations. With the implementation of a strong analytical method called HAM, the solution of resulting higher-order ordinary differential equations is obtained. The results of the skin friction coefficient, Nusselt number, velocity profile, and temperature profile of the hybrid nanofluid for varying different flow parameters are attained in the form of graphs and tables. Some important outcomes showed that the Nusselt number and skin friction are increased with the enhancement in Eckert number, stretching parameter, heat generation parameter and radiation parameter for both slip and no-slip conditions. The thermal profile of the hybrid nanofluid is higher for suction effect but lower for Eckert number, stretching parameter, magnetic field, heat generation and radiation parameter. For both slip and no-slip conditions, the hybrid nanofluid velocity shows an upward trend for both the stretching and mixed convection parameters.

scholarly journals Exact Analytical Solution for Suction and Injection Flow with Thermal Enhancement of Five Nanofluids over an Isothermal Stretching Sheet with Effect of the Slip Model: A Comparative Study

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Emad H. Aly ◽  
Abdelhalim Ebaid
Keyword(s):  
Nusselt Number ◽  
Analytical Solution ◽  
Silicon Dioxide ◽  
Skin Friction ◽  
Stretching Sheet ◽  
Exact Analytical Solution ◽  
Physical Parameters ◽  
Slip Model ◽  
Local Skin ◽  
Local Skin Friction

We introduced a direct and effective approach to obtain the exact analytical solution for the nanoparticles-water flow over an isothermal stretching sheet with the effect of the slip model. In particular, we examined and compared the effect of the existence of five metallic and nonmetallic nanoparticles, namely, Silver, Copper, Alumina, Titania, and Silicon Dioxide, in a base of water. The most interesting physical parameters were then discussed in the presence of no-slip model, first order slip, and second order slip parameters. It is found that, with no-slip effect, the present exact solutions are in a very good agreement with the previous published results. On the other hand, with the effect of the slip model, increase in the nanoparticle volume friction decreases the velocity for the high density of nanoparticles, increases it for the low density of them, and increases the temperature for all investigated nanoparticles. Further, increase in the wall mass decreases the velocity and temperature; however, it increases the local skin friction. Furthermore, increase in the slips slows down the velocity, increases the temperature with an impressive effect in the injection case, and decreases the local skin friction and the reduced Nusselt number. It was also demonstrated that, as the nanoparticle becomes heavier, this results in increase and decrease in reduced skin friction coefficient and reduced Nusselt number, respectively, with significant effect in the presence of the second slip. Finally, Silver is the suitable nanoparticle if slowing down the velocity and increasing the temperature are needed; Silicon Dioxide is the appropriate nanoparticle if different behavior is to be considered.

scholarly journals Unsteady MHD chemically reacting fluid through a porous medium bounded by a non-isothermal impulsively-started vertical plate: a numerical technique

2014 ◽  
Vol 11 (1) ◽  
pp. 39-54
Author(s):  
Sahin Ahmed ◽  
Karabi Kalita
Keyword(s):  
Porous Medium ◽  
Nusselt Number ◽  
Skin Friction ◽  
Chemical Reaction ◽  
Sherwood Number ◽  
Vertical Plate ◽  
Convection Flow ◽  
Local Skin ◽  
Porosity Parameter ◽  
Local Skin Friction

A numerical modeling on MHD transient mass transfer by free convection flow of a viscous, incompressible, electrically-conducting, and Newtonian fluid through a porous medium bounded by an impulsively-started semi-infinite vertical plate in the presence of thermal radiation and chemical reaction of first order has been analyzed. The fluid is assumed optically thin gray gas, absorbing-emitting radiation, but a non-scattering medium. The dimensionless governing coupled, non-linear boundary layer partial differential equations are solved by an efficient, accurate, extensively validated and unconditionally stable finite difference scheme of the Crank-Nicolson type. The effects of the conduction-radiation parameter , chemical reaction and the porosity (K) on the velocity, temperature and concentration fields have been studied. The local skin friction, Nusselt number and the Sherwood number are also presented graphically and analyzed. Increasing magnetic parameter serves to decelerate the flow but increased temperatures and concentration values. It is found that the velocity is increased considerably with a rise in the porosity parameter (K) whereas the temperature and concentration are found to be reduced with increasing porosity (K). An increase in the porosity parameter (K) is found to escalate the local skin friction , Nusselt number and the Sherwood number . Possible applications of the present study include laminar aerodynamics, materials processing and thermo-fluid dynamics.DOI: http://dx.doi.org/10.3329/jname.v11i1.10269

Radiative hybrid nanofluid flow past a rotating permeable stretching/shrinking sheet

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Nur Syazana Anuar ◽  
Norfifah Bachok ◽  
Ioan Pop
Keyword(s):  
Nusselt Number ◽  
Stability Analysis ◽  
Differential Equations ◽  
Skin Friction ◽  
Local Nusselt Number ◽  
Current Work ◽  
Shrinking Sheet ◽  
Hybrid Nanofluid ◽  
Local Skin ◽  
Content Type

Purpose This paper aims to discuss a stability analysis on Cu-Al2O3/water nanofluid having a radiation and suction impacts over a rotating stretching/shrinking sheet. Design/methodology/approach The partial differential equations are converted into nonlinear ordinary differential equations using similarity transformation and then being solved numerically using built in function in Matlab software (bvp4c). The effects of pertinent parameters on the temperature and velocity profiles together with local Nusselt number and skin friction are reported. Findings Compared to previously published studies, the current work is noticed to be in good deal. The analysis further shows that the non-unique solutions exist for certain shrinking parameter values. Hence, a stability analysis is executed using a linear temporal stability analysis and concluded that the second solution is unstable, while the first solution is stable. The effect of suction parameter is observed to be significant in obtaining the solutions. The improvement of the local skin friction and the decrease of the local Nusselt number on the shrinking surface are observed with the increment of the copper nanoparticle volume fractions. Originality/value The originality of current work is the numerical solutions and stability analysis of hybrid nanofluid in rotating flow. This work has also resulted in producing the non-unique solutions for the shrinking sheet, and a stability analysis has also been executed for this flow showing that the second solution is unstable, while the first solution is stable. This paper is therefore valuable for engineers and scientist to get acquainted with the properties of the flow, its behavior and the way to predict it. The authors admit that all the findings are original and were not published anywhere else.

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