scholarly journals Analysis of the Physical Behavior of the Periodic Mixed-Convection Flow around a Nonconducting Horizontal Circular Cylinder Embedded in a Porous Medium

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Muhammad Ashraf ◽  
Zia Ullah ◽  
Saqib Zia ◽  
Sayer O. Alharbi ◽  
Dumitru Baleanu ◽  
...  

An oscillatory mixed-convection fluid flow mechanism across a nonconducting horizontal circular cylinder embedded in a porous medium has been computed. For this purpose, a model in the form of partial differential equations is formulated, and then, the governing equations of the dimensionless model are transformed into the primitive form for integration by using primitive variable formulation. The impact of emerging parameters such as porous medium parameter Ω , Richardson number λ , magnetic force parameter ξ , and Prandtl number Pr on skin friction, heat transfer, and current density is interpreted graphically. It is demonstrated that accurate numerical results can be obtained by the present method by treating nonoscillating and oscillating parts of coupled partial differential equations simultaneously. In this study, it is well established that the transient convective heat transfer, skin friction, and current density depend on amplitude and phase angle. One of the objects of the present study is to predict the mechanism of heat and fluid flow around different angles of a nonconducting horizontal circular cylinder embedded in a porous medium.

2000 ◽  
Vol 28 (2) ◽  
pp. 174-184 ◽  
Author(s):  
Mark R. D. Davies ◽  
Tara M. Dalton

A new method of dimensional analysis is presented by demonstrating its application to a range of problems in fluid flow and heat transfer. The technique is a development of a previously published and accepted method of inspectional analysis. This new technique is shown to give the correct results on both simple equations with solutions, and on more complex sets of partial differential equations without solutions. This development of a single method from the simple to the complex has obvious teaching advantages.


2013 ◽  
Vol 135 (10) ◽  
Author(s):  
L. Tham ◽  
R. Nazar ◽  
I. Pop

In this paper, the steady mixed convection boundary layer flow past a horizontal circular cylinder with a constant surface temperature embedded in a porous medium saturated by a nanofluid containing both nanoparticles and gyrotactic micro-organisms in a stream flowing vertically upwards for both cases of a heated and cooled cylinder is numerically studied. The resulting system of nonlinear partial differential equations is solved numerically using an implicit finite-difference scheme. By considering the governing parameters, namely, the mixed convection parameter λ, the bioconvection Lewis number Lb, the traditional Lewis number Le, the bioconvection Péclet number Pb, the buoyancy ratio Nr, the bioconvection Rayleigh number Rb, the Brownian motion Nb, and the thermophoresis Nt, the numerical results are obtained and discussed for the skin friction coefficient, the local Nusselt number, the local Sherwood number, the local density number of the motile micro-organisms as well as the velocity, temperature, nanoparticle volume fraction, and density motile micro-organisms profiles.


This chapter describes the pdepe command, which is used to solve spatially one-dimensional partial differential equations (PDEs). It begins with a description of the standard forms of PDEs and its initial and boundary conditions that the pdepe solver uses. It is shown how various PDEs and boundary conditions can be represented in standard forms. Applications to the mechanics are presented in the final part of the chapter. They illustrate how to solve: heat transfer PDE with temperature dependent material properties, startup velocities of the fluid flow in a pipe, Burger's PDE, and coupled FitzHugh-Nagumo PDE.


2020 ◽  
Vol 12 (5) ◽  
pp. 657-661
Author(s):  
Zohreh Aliannejadi

In many cases such as production of metal sheets, the behavior of fluid flow and heat transfer in the neighborhood of a hot plate is very important. The CFD simulation of fluid flow is a widespread study that reveals detail information about the fluid flow in the calculated domain. In this study, the flow and heat transfer of a specific fluid in the above area of a stretching plate is examined analytically to find the variation of skin friction and Nusselt number. For this purpose, the similarity transformations can be employed to achieve the ordinary differential equations from the governing partial differential equations. The optimal homotopy asymptotic method (OHAM) is used to solve the ordinary differential equations which is applicable in solving of nonlinear equations. The effects of magnetic field on the analytical results from solving the equations are evaluated in detail. It is found that the thickness of the flow boundary layer decreases and the thickness of the thermal boundary layer increases by increasing in the magnetic field. Moreover, the Nusselt number is lower and skin friction is higher for the higher values of the magnetic field.


Author(s):  
Minh Tuan Nguyen ◽  
Abdelraheem M. Aly ◽  
Sang-Wook Lee

Purpose This paper aims to conduct numerical simulations of unsteady natural/mixed convection in a cavity with fixed and moving rigid bodies and different boundary conditions using the incompressible smoothed particle hydrodynamics (ISPH) method. Design/methodology/approach In the ISPH method, the pressure evaluation is stabilized by including both of divergence of velocity and density invariance in solving pressure Poisson equation. The authors prevented the particles anisotropic distributions by using the shifting technique. Findings The proposed ISPH method exhibited good performance in natural/mixed convection in a cavity with fixed, moving and free-falling rigid body. In natural convection, the authors investigated the effects of an inner sloshing baffle as well as fixed and moving circular cylinders on the heat transfer and fluid flow. The heated baffle has higher effects on the heat transfer rate compared to a cooled baffle. In the mixed convection, a free-falling circular cylinder over a free surface cavity and heat transfer in the presence of a circular cylinder in a lid-driven cavity are simulated. Fixed or moving rigid body in a cavity results in considerable effects on the heat transfer rate and fluid flow. Originality/value The authors conducted numerical simulations of unsteady natural/mixed convection in a cavity with fixed and moving rigid bodies and different boundary conditions using the ISPH method.


2020 ◽  
Vol 34 (24) ◽  
pp. 2050255
Author(s):  
Aamir hamid ◽  
Abdul Hafeez ◽  
Masood Khan

In this paper, the combined heat and mass transfer of mixed convection, non-similar Sisko fluid flow in the presence of a magnetic field is studied. The combined effects of thermal radiation and heat generation/absorption are examined for Sisko fluid flow via local non-similar method. For the radiative heat transfer, Rosseland approximation model is used. The governing partial differential equations of the present problem are transformed into a system of nonlinear ordinary differential equations by employing the Sparrow–Quack–Boerner local non-similarity method (LNM). The obtained equations are then numerically investigated by utilizing the bvp4c function in MATLAB. The impact of different supervising parameters on the velocity, temperature, skin friction and rate of heat transfer is performed graphically. It is observed that the velocity is more for a higher rate of the buoyancy force parameter while it is less for opposing buoyancy fluid. The thermal boundary layer thickness for the shear thickening fluids is smaller than the shear thinning fluids.


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