scholarly journals Mixed Convection Flow Along Vertical Thin Needles Containing Gyrotactic Microorganism with Variable Heat, Mass and Motile Microorganism Flux

2021 ◽  
Author(s):  
Nayema Islam Nima ◽  
Bader Alshuraiaan ◽  
M. Ferdows
Keyword(s):  
Mixed Convection ◽  
Convection Flow ◽  
Convection Boundary Layer ◽  
Needle Size ◽  
Similarity Transformations ◽  
Laminar Mixed Convection ◽  
Variable Surface ◽  
Fluid Concentration ◽  
Layer Flow ◽  
Gyrotactic Microorganism

Abstract The problem of steady laminar mixed convection boundary layer flow along vertical thin needle with variable surface heat, mass and motile microorganism flux in the presence of gyrotactic microorganism is considered in this study. The dimensionless leading equations of continuity, momentum, concentraton and motile microorganism conservation are reduced to ordinary differential equations with the help of similarity transformations. The transformed governing equations are then numerically solved by using MATLAB BVP4C function. The research is reached to excellent argument by comparison in few cases between the results obtained from MATLAB and Maple algorithm with the help of dsolve command. Numerical calculations are carried out for various values of the dimensionless parameters of the problem which includes mixed convection parameter λ, power law index m, buoyancy parameters N1, N2 Lewis parameter Le, bioconvection lewis parameter Lb, Bioconvection peclet number Pe and also the parameter a representing the needle size. It is also shown from the results that the surface (wall) temperature, surface fluid concentration, surface motile microorganism concentration and the corresponding velocity, temperature, concentration and motile microorganism profiles are significantly induced by these parameters. The results are pictured and discussed in detail.

MHD mixed convection flow of a viscoelastic fluid over an inclined surface with a nonuniform heat source/sink

2013 ◽  
Vol 91 (12) ◽  
pp. 1074-1080 ◽  
Author(s):  
G.K. Ramesh ◽  
Ali J. Chamkha ◽  
B.J. Gireesha
Keyword(s):  
Differential Equations ◽  
Mixed Convection ◽  
Viscoelastic Fluid ◽  
Convection Flow ◽  
Convection Boundary Layer ◽  
Similarity Transformations ◽  
Different Types ◽  
Layer Flow ◽  
Source Sink ◽  
Inclined Surface

The steady mixed convection boundary layer flow over an inclined stretching surface immersed in an incompressible viscoelastic fluid is considered in this paper. Employing suitable similarity transformations, the governing partial differential equations are transformed into ordinary differential equations, and the transformed equations are solved numerically using Runge–Kutta–Fehlberg method. Herein, two different types of heating processes are considered, namely, (i) prescribed surface temperature and (ii) prescribed wall heat flux. The effects of the governing parameters on the flow field and heat transfer characteristics are obtained and discussed. It is found that velocity decreases and temperature increases with an increase in the value of angle of inclination.

Laminar Mixed Convection Boundary Layer Flow Over Two Dimensional and Axisymmetric Bodies

2013 ◽  
Author(s):  
Sufianu A. Aliu ◽  
Richard O. Fagbenle
Keyword(s):  
Heat Transfer ◽  
Mixed Convection ◽  
Numerical Solutions ◽  
Convection Flow ◽  
Convection Boundary Layer ◽  
Two Dimensional ◽  
Universal Functions ◽  
Laminar Mixed Convection ◽  
Layer Flow ◽  
Axisymmetric Bodies

Simple and familiar perturbation parameters have been employed in applying the corrected Merk series of Chao and Fagbenle to the laminar mixed convection flow over two dimensional or axisymmetric bodies. The governing ordinary differential equations for the first five sets of the resulting universal functions for the velocity and temperature have been given. Numerical solutions were subsequently obtained and the relevant universal functions tabulated with respect to the ‘wedge parameter’ for mixed convection two dimensional flows and with respect to both the ‘wedge parameter’ and ‘shape parameter’ for the axisymmetric case. Using the wall derivatives of these universal functions, friction and heat transfer in mixed convection flows over two dimensional or axisymmetric bodies have been obtained and used in evaluation of skin friction and surface heat transfer.

g-Jitter Induced Mixed Convection Flow of Heat and Mass Transfer Past an Inclined Stretching Sheet

2014 ◽  
Vol 71 (1) ◽  
Author(s):  
Noraihan Afiqah Rawi ◽  
Abdul Rahman Mohd Kasim ◽  
Mukheta Isa ◽  
Sharidan Shafie
Keyword(s):  
Mass Transfer ◽  
Differential Equations ◽  
Mixed Convection ◽  
Heat And Mass Transfer ◽  
Stretching Sheet ◽  
Convection Flow ◽  
Convection Boundary Layer ◽  
Keller Box Method ◽  
Unsteady Mixed Convection ◽  
Layer Flow

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.

Mixed convection flow, heat transfer, species concentration near the stagnation point on a vertical flat plate with Stefan coupled blowing

2017 ◽  
Vol 27 (1) ◽  
pp. 77-103 ◽  
Author(s):  
Natalia C. Rosca ◽  
Alin V. Rosca ◽  
John H. Merkin ◽  
Ioan Pop
Keyword(s):  
Mixed Convection ◽  
Stagnation Point ◽  
Numerical Solutions ◽  
Relative Strength ◽  
Convection Flow ◽  
Convection Boundary Layer ◽  
Mixed Convection Flow ◽  
Outer Flow ◽  
Content Type ◽  
Layer Flow

Purpose The purpose of this study is to consider the effects that buoyancy arising from the combination of both thermal and concentration gradients can have on the mixed convection boundary-layer flow near a forward stagnation point with the effect of Stefan blowing being included. Ad suitable choice for the functional forms of the outer flow and the wall temperature and concentration enables the problem to be reduced to a similarity form involving the dimensionless parameters, λ (mixed convection), κ (Stefan blowing) and N (relative strength of concentration driven buoyancy to that of thermal driven), as well as the Prandtl and Schmidt numbers. Numerical solutions to this similarity system for a range of representative parameter values indicate a finite, non-zero range of κ where there can be four solutions in opposing flow with only one solution in aiding flow. Asymptotic solutions for large values of N and κ are derived, the latter having two different structures in the opposing flow. Design/methodology/approach This paper sets up a similarity problem to examine the effects of Stefan blowing on a mixed convection flow with the aims of solving the equations numerically and complementing the results with appropriate asymptotic analysis. Findings The findings of the study include multiple solution branches, saddle-node bifurcations and singularities appearing in the solution. Originality/value The authors believe that all the results, both numerical and asymptotic, are original and have not been published elsewhere.

Solar Radiation Assisted Mixed Convection Flow Along a Vertical Plate

2014 ◽  
Vol 31 (1) ◽  
pp. N1-N8
Author(s):  
S. Siddiqa ◽  
M. A. Hossain
Keyword(s):  
Solar Radiation ◽  
Mixed Convection ◽  
Vertical Plate ◽  
Gaussian Elimination ◽  
Computation Time ◽  
Convection Flow ◽  
Convection Boundary Layer ◽  
Coupled Equations ◽  
Layer Flow ◽  
Stream Function Formulation

ABSTRACTSolar radiation assisted mixed convection boundary layer flow of Newtonian fluid along a non- reflecting, non-absorbing and ideally transparent semi-infinite vertical plate is studied here. Beer's law is used to express the solar radiation term. It is convenient to transform the non-linear dimensionless parabolic partial differential equations into (i) primitive variable formulation (PVF) and (ii) stream function formulation (SFF) before applying the numerical schemes. Coupled equations thus obtained from PVF are integrated numerically through implicit finite difference method together with the Gaussian elimination technique whereas block tridiagonal Keller-box technique is adopted to simulate the system of equations obtained from SFF. Numerical results from these two methods are also compared graphically in order to test the validation of the two schemes. However, due to less computation time and accuracy numeric results of shear stress, local Nusselt number coefficient, velocity and temperature profiles are obtained via SFF. It is found that velocity as well as temperature of the non-absorbing fluid enhances owing to the increase in solar radiation parameter.

scholarly journals Homotopy simulation of axisymmetric laminar mixed convection nanofluid boundary layer flow over a vertical cylinder

2012 ◽  
Vol 39 (4) ◽  
pp. 365-390 ◽  
Author(s):  
M.M. Rashidi ◽  
Anwar Bég ◽  
Mehr Freidooni ◽  
A. Hosseini ◽  
R.S.R. Gorla
Keyword(s):  
Boundary Layer ◽  
Mixed Convection ◽  
Volume Fraction ◽  
Numerical Technique ◽  
Vertical Cylinder ◽  
Similarity Solutions ◽  
Convection Boundary Layer ◽  
Laminar Mixed Convection ◽  
Homotopy Analysis ◽  
Layer Flow

In this paper, the semi-analytical/numerical technique known as the homotopy analysis method (HAM) is employed to derive solutions for the laminar axisymmetric mixed convection boundary-layer nanofluid flow past a vertical cylinder. The similarity solutions are employed to transform the parabolic partial differential conservation equations into system of nonlinear, coupled ordinary differential equations, subject to appropriate boundary conditions. A comparison has been done to verify the obtained results with the purely numerical results of Grosan and Pop (2011) with excellent correlation achieved. The effects of nanoparticle volume fraction, curvature parameter and mixed convection or buoyancy parameter on the dimensionless velocity and temperature distributions, skin friction and wall temperature gradients are illustrated graphically. HAM is found to demonstrate excellent potential for simulating nanofluid dynamics problems. Applications of the study include materials processing and also thermal enhancement of energy systems.

scholarly journals MHD Mixed Convection Flow of Viscoelastic Fluid Embedded in Porous Medium

2013 ◽  
Vol 9 (1) ◽  
Author(s):  
A.R.M. Kasim ◽  
N.F. Mohammad ◽  
Aurangzaib Aurangzaib ◽  
S. Shafie
Keyword(s):  
Porous Medium ◽  
Mixed Convection ◽  
Viscoelastic Fluid ◽  
Convection Flow ◽  
Convection Boundary Layer ◽  
Local Skin ◽  
Viscoelastic Parameter ◽  
Keller Box Method ◽  
Local Skin Friction ◽  
Layer Flow

An analysis has been carried out to investigate the effect of magnetic field presence on the mixed convection boundary layer flow of viscoelastic fluid over a horizontal circular cylinder in a porous medium. The governing non-similar partial differential equations are transformed into dimensionless forms and then solved numerically using the Keller-box method. Some important parameters have been discussed in this study which include the Prandtl number (Pr), magnetic parameter (M), viscoelastic parameter (K), porosity parameter (γ) and the mixed convection parameters (λ). The results show the values of the velocity decrease when the value of viscoelastic parameter increase and the reverse trend were observe for temperature profile. Numerical results of local skin friction as well as local Nusselt number are also presented in tabular form.

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