Analysis of laminar mixed-convection condensation on isothermal plates using the full boundary-layer equations: mixtures of a vapor and a lighter gas

1999 ◽  
Vol 42 (4) ◽  
pp. 685-695 ◽  
Author(s):  
V. Srzic ◽  
H.M. Soliman ◽  
S.J. Ormiston
Keyword(s):  
Boundary Layer ◽  
Mixed Convection ◽  
Boundary Layer Equations ◽  
Laminar Mixed Convection

Unsteady Mixed Convection From a Moving Vertical Slender Cylinder

2005 ◽  
Vol 128 (4) ◽  
pp. 368-373 ◽  
Author(s):  
S. Roy ◽  
D. Anilkumar
Keyword(s):  
Heat Transfer ◽  
Mixed Convection ◽  
Skin Friction Coefficient ◽  
Surface Mass ◽  
Boundary Layer Equations ◽  
Surface Mass Transfer ◽  
Laminar Mixed Convection ◽  
Unsteady Mixed Convection ◽  
Implicit Finite Difference Scheme ◽  
Momentum And Heat Transfer

A general analysis has been developed to study flow and heat transfer characteristics of an unsteady laminar mixed convection on a continuously moving vertical slender cylinder with surface mass transfer, where the slender cylinder is inline with the flow. The unsteadiness is introduced by the time-dependent velocity of the slender cylinder as well as that of the free stream. The calculations of momentum and heat transfer on slender cylinders considered the transverse curvature effect, especially in applications such as wire and fiber drawing, where accurate predictions are required. The governing boundary layer equations along with the boundary conditions are first cast into a dimensionless form by a nonsimilar transformation, and the resulting system of nonlinear coupled partial differential equations is then solved by an implicit finite difference scheme in combination with the quasi-linearization technique. Numerical results are presented for the skin friction coefficient and Nusselt number. The effects of various parameters on the velocity and temperature profiles are also reported here.

scholarly journals Unsteady laminar mixed convection boundary layer flow near a vertical wedge due to oscillations in the free-stream and surface temperature

2016 ◽  
Vol 21 (1) ◽  
pp. 169-186 ◽  
Author(s):  
N.C. Roy ◽  
Md. A. Hossain ◽  
S. Hussain
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Mixed Convection ◽  
Surface Temperature ◽  
Skin Friction ◽  
Free Stream ◽  
Asymptotic Series ◽  
Frequency Range ◽  
Laminar Mixed Convection ◽  
Vertical Wedge

Abstract The unsteady laminar boundary layer characteristics of mixed convection flow past a vertical wedge have been investigated numerically. The free-stream velocity and surface temperature are assumed to be oscillating in the magnitude but not in the direction of the oncoming flow velocity. The governing equations have been solved by two distinct methods, namely, the straightforward finite difference method for the entire frequency range, and the extended series solution for low frequency range and the asymptotic series expansion method for high frequency range. The results demonstrate the effects of the Richardson number, Ri, introduced to quantify the influence of mixed convection and the Prandtl number, Pr, on the amplitudes and phase angles of the skin friction and heat transfer. In addition, the effects of these parameters are examined in terms of the transient skin friction and heat transfer.

scholarly journals Mixed Convection Boundary Layers with Prescribed Temperature in the Unsteady Stagnation Point Flow toward a Stretching Vertical Sheet

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Nik Mohd Asri Nik Long ◽  
Lee Feng Koo ◽  
Tze Jin Wong ◽  
Melini Suali
Keyword(s):  
Boundary Layer ◽  
Mixed Convection ◽  
Stagnation Point ◽  
Flow Characteristics ◽  
Skin Friction Coefficient ◽  
Stagnation Point Flow ◽  
Convection Boundary Layer ◽  
Shooting Technique ◽  
Boundary Layer Equations ◽  
Convection Boundary

Mixed convection boundary layer caused by time-dependent velocity and the surface temperature in the two-dimensional unsteady stagnation point flow of an in-compressible viscous fluid over a stretching vertical sheet is studied. The transformed nonlinear boundary layer equations are solved numerically using the shooting technique in cooperation with Runge-Kutta-Fehlberg (RKF) method. Different step sizes are used ranging from 0.0001 to 1. Numerical results for the skin friction coefficient and local Nusselt number are presented for both assisting and opposing flows. It is found that the dual solutions exist for the opposing flow, whereas the solution is unique for the assisting flow. Important features of the flow characteristics are displayed graphically. Comparison with the existing results for the steady case show an excellent agreement.

Keller-Box Scheme to Mixed Convection Flow Over a Solid Sphere with the Effect of MHD

2021 ◽  
Vol 6 (1) ◽  
pp. 97
Author(s):  
Mohammad Ghani ◽  
Wayan Rumite
Keyword(s):  
Boundary Layer ◽  
Free Convection ◽  
Mixed Convection ◽  
Numerical Solutions ◽  
Solid Sphere ◽  
Convection Flow ◽  
Boundary Layer Equations ◽  
Buoyancy Forces ◽  
Dimensional Boundary ◽  
External Forces

Mixed convection is the combination of a free convection caused by the buoyancy forces due to the different density and a forced convection due to external forces that increase the heat exchange rate. This means that, in free convection, the effect of external forces is significant besides buoyancy forces. In this study the fluid type with viscoelastic effect is non-Newtonian. The viscoelastic fluids that pass over a surface of a sphere form a thin layer, which due to their dominant viscosity is called by the border layer. The obtained limiting layer is analyzed with the thickness of the boundary layer-  near the lower stagnating point, then obtained dimensional boundary layer equations, continuity, momentum, and energy equations. These dimensional boundary layer equations are then transformed into non-dimensional boundary layer equations by using non-dimensional variables. Further, the non-dimensional boundary layer equations are transformed into ordinary differential equations by using stream function, so that obtained the non-similar boundary layer equations. These non-similar boundary layer equations are solved numerically by using finite difference method of Keller-Box. The discretization results are non-linear and it should be linearized using newton linearization technique. The numerical solutions are analyzed the effect of Prandtl number, viscoelastic, mixed convection, and MHD parameters towards velocity profile, temperature profile, and wall temperature.

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