Laminar Heat Transfer in a Parallel Plate Channel With Solid and Porous Baffles

Author(s):  
Marcelo J. S. de Lemos ◽  
Nicolau B. Santos

Simulations are presented for laminar flow in a channel containing fins made with solid (impermeable) and porous materials. The equations of mass continuity, momentum and energy are written for an elementary representative volume yielding a set of equations valid for the entire computational domain. These equations are discretized using the control volume method and the resulting system of algebraic equations is relaxed with the SIMPLE method. The presented numerical results for the friction factor f and the Nusselt number Nu were compared with available data indicating that results herein differ by less than 5% in relation to published results. Further simulations comparing the effectiveness of the porous material used showed that no advantages are obtained for using low porosity baffles in the laminar flow regime.

Author(s):  
Marcelo J. S. de Lemos ◽  
Nicolau B. Santos

Simulations are presented for turbulent flow in a channel containing baffles made with solid and porous materials. The equations of mass continuity, momentum and energy are written for an elementary representative volume yielding a set of equations valid for the entire computational domain. These equations are discretized using the control volume method and the resulting system of algebraic equations is relaxed with the SIMPLE method. The presented numerical results for the friction factor f and for the Nusselt number Nu were compared with available data. Further simulations comparing the effectiveness of the porous material used showed that no advantages are obtained when using low porosity baffles in the turbulent flow regime.


Author(s):  
Marcelo J. S. de Lemos ◽  
Luzia A. Tofaneli

In this work, numerical solutions are presented for turbulent flow in a channel containing fins made with porous material. The condition of spatially periodic cell is applied longitudinally along the channel. A macroscopic tow-equation turbulence model is employed in both the porous region and the clear fluid. The equations of momentum, mass continuity and turbulence transport equations are written for an elementary representative volume yielding a set of equations valid for the entire computational domain. These equations are discretized using the control volume method and the resulting systems of algebraic equations is relaxed with the SIMPLE method. Results are presented for the velocity field as a function of Reynolds number, porosity and permeability of the fins.


Author(s):  
Cemil Koyunoğlu

Mathematical modeling of the heat pump as a result of continuity, momentum, and energy equations is obtained. To solve these equations numerically, the problem is divided by a finite number of control volumes. Then the differential equations in these control volumes integrated and converted into algebraic equations. The importance of computational fluid dynamics in Industry 4.0 applications is to make current applications more efficient in heat pump applications. In this study, the book section is composed of the application of computational fluid dynamics by the control volume method using Ansys fluent program, which will benefit readers from industry 4.0 perspective, especially in energy efficiency issues according to the volume method of controlling correct heat pump designs.


2017 ◽  
Vol 139 (10) ◽  
Author(s):  
Paulo H. S. Carvalho ◽  
Marcelo J. S. de Lemos

This work presents a study on double-diffusive free convection in a porous square cavity using the thermal equilibrium model. Transport equations are discretized using the control-volume method, and the system of algebraic equations is relaxed via the SIMPLE algorithm. The effect of ks/kf on average Nusselt and Sherwood values was investigated. Results show that increasing ks/kf affects Nuw and Shw boosting mass transfer at the expense of reducing overall heat transport across the enclosure.


Author(s):  
Ali Arefmanesh ◽  
Mohammad Najafi ◽  
Hooman Abdi

A novel meshless numerical technique to solve computational fluid dynamics-heat transfer problems is introduced. The theory behind the newly proposed technique hereafter named “The Meshless Control Volume Method” is explained and a number of examples illustrating the implementation of the method is presented. In this study, the technique is applied for one and two dimensional transient heat conduction as well as one and two dimensional advection-diffusion problems. Compared to other methods including the exact solution, the results show to be highly accurate for the considered cases. Being a meshless technique, the control volumes are arbitrary chosen, and they posses simple shapes which contrary to the existing control volume methods can overlap. The number of points within each control volume and, therefore the degree of interpolation can be different throughout the considered computational domain. Since the control volumes are of simple shapes, the integrals can be evaluated analytically.


Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 868
Author(s):  
Simona Fialová ◽  
František Pochylý

In this paper, new forms of Maxwell’s equations in vector and scalar variants are presented. The new forms are based on the use of Gauss’s theorem for magnetic induction and electrical induction. The equations are formulated in both differential and integral forms. In particular, the new forms of the equations relate to the non-stationary expressions and their integral identities. The indicated methodology enables a thorough analysis of non-stationary boundary conditions on the behavior of electromagnetic fields in multiple continuous regions. It can be used both for qualitative analysis and in numerical methods (control volume method) and optimization. The last Section introduces an application to equations of magnetic fluid in both differential and integral forms.


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