Laminar Free Convection From a Vertical Infinite Plate Subject to Transverse Oscillation

1964 ◽  
Vol 31 (3) ◽  
pp. 383-389 ◽  
Author(s):  
Victor D. Blankenship ◽  
John A. Clark

The laminar free-convection boundary layer on a vertical plane wall vibrating transversely at high frequencies is analyzed utilizing a perturbation technique. The zeroth-order solutions are that of the well-known steady free-convection flow. First-order harmonic oscillations in velocity and temperature and a second-order time-independent secondary flow and heat transfer are obtained. Series solution for shear stress and Nusselt number are presented having both time-dependent and time-independent terms. Prandtl numbers of 0.72 and 10 are investigated. The time-independent or steady Nusselt number was found to decrease while the shear stress was found to increase under the influence of oscillations.

2021 ◽  
Vol 12 (5) ◽  
pp. 6280-6296

This work studies the steady two-dimensional MHD free convection flow past an inclined porous plate embedded in the porous medium in the presence of heat source, iSoret effect, and chemical reaction. The non-dimensional governing equations are solved by the perturbation technique. The Rosseland approximation is utilized to describe the radiative heat flux in the energy equation. The effect of magnetic parameter, heat source parameter, radiation parameter, Grashofi number, modified Grashofi number, Schmidt number, Prandtl number, porosity parameter, Soreti number, and chemical reaction on velocity, temperature, concentration profiles, skin friction, Nusselt number, and Sherwood number are mainly focussed in discussion with the help of graphs. It is seen that velocity, concentration, and skin friction fall with the increasing value of chemical reaction. Further, temperature, Nusselt number, and Sherwood number increase with the increasing value of chemical reaction.


1979 ◽  
Vol 101 (4) ◽  
pp. 642-647 ◽  
Author(s):  
M. M. Hasan ◽  
R. Eichhorn

The effect of the angle of inclination on free convection flow and heat transfer from an isothermal surface is analyzed by the local nonsimilarity method of solution. An inclination parameter ξ as obtained from the analysis is tan γ/4 (Grx/4)1/4, where γ is the angle of inclination measured from the vertical and Grx is the local Grashof number, based on the component of the gravity vector along the surface. Numerical solutions of the equations are obtained for Prandtl numbers of 0.1, 0.7, 6 and 275. Results show an appreciable effect of ξ on the velocity field, and practically none on the temperature field, except for very large angles of inclination from the vertical or for very small values of the Prandtl number. In the limiting case of very large Prandtl number, ξ has no effect either on the velocity or the temperature field.


2018 ◽  
Vol 22 (6 Part A) ◽  
pp. 2503-2514 ◽  
Author(s):  
Esfe Hemmat ◽  
Arani Abbasian ◽  
Wei-Mon Yan ◽  
Alireza Aghaie ◽  
Masoud Afrand ◽  
...  

The present study aims to evaluate the mixed convection flow and heat transfer of functionalized DWCNT/water nanofluids with variable properties in a cavity having hot baffles. The investigation is performed at different nanoparticles volume fraction including 0, 0.0002, 0.001, 0.002, and 0.004, Richardson numbers ranging from 0.01 to 100, inclination angles ranging from 0 to 60? and at constant Grashof number of 104. The results presented as streamlines and isotherms plot and Nusselt number diagrams. According to the finding with increasing nanoparticles volume fraction and distance between the left hot baffles of nanoparticles average Nusselt number enhances for all considered Richardson numbers and cavity inclination angles. Also with increasing Richardson number, the rate of changes of average Nusselt number increase with increasing distance between the left hot baffles. For example, at Richardson number of 0.01, by increasing L1 from 0.4 to 0.6, the average Nusselt number increases 7%; while for similar situation at Richardson number of 0.1, 1.0, and 10, the average Nusselt number increases, respectively, 17%, 24%, and 26%. At all Richardson numbers, the maximum value of average Nusselt number is achieved for a minimum length of left baffles. <br><br><font color="red"><b> This article has been corrected. Link to the correction <u><a href="http://dx.doi.org/10.2298/TSCI190203032E">10.2298/TSCI190203032E</a><u></b></font>


2016 ◽  
Vol 78 (3-2) ◽  
Author(s):  
Arshad Khan ◽  
Ilyas Khan ◽  
Sharidan Shafie

Effects of Newtonian heating and mass diffusion on magnetohydrodynamic free convection flow over a vertical plate that applies arbitrary shear stress to the fluid is studied. The fluid is considered electrically conducting and passing through a porous medium. The influence of thermal radiation in the energy equations is also considered. General solutions of the problem are obtained in closed form using the Laplace transform technique. They satisfy the governing equations, initial and boundary conditions and can set up a huge number of exact solutions correlatives to various fluid motions. The effects of various parameters on velocity profiles are shown graphically and discussed in details


2013 ◽  
Vol 62 (3) ◽  
Author(s):  
Muhamad Najib Zakaria ◽  
Abid Hussanan ◽  
Ilyas Khan ◽  
Sharidan Shafie

The present paper is on study of the influence of radiation on unsteady free convection flow of Brinkman type fluid near a vertical plate containing a ramped temperature profile. Using the appropriate variables, the basic governing equations are reduced to nondimensional equations valid with the imposed initial and boundary conditions. The exact solutions are obtained by using Laplace transform technique. The influence of radiation near a ramped temperature plate is also compared with the flow near a plate with constant temperature. The numerical computations are carried out for various values of the physical parameters such as velocity, temperature, skin friction and Nusselt number and presented graphically.


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