Numerical investigation of natural convection heat transfer in a symmetrically cooled square cavity with a thin fin on its bottom wall (original) (raw)
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Heat Transfer Research, 2011
Fluid flow and natural convection heat transfer in a differentially heated square cavity with a fin attached to its cold wall is investigated numerically. The top and the bottom horizontal walls of the cavity are insulated while the left and right vertical walls of the cavity are maintained at a constant temperature T h and T c , with T h > T c , respectively. The governing equations written in terms of the primitive variables are solved numerically using the finite volume method and the SIMPLER algorithm. Using the developed code, a parametric study is performed, and the effects of the Rayleigh number, length of the fin and its position on the flow pattern and heat transfer inside the enclosure are investigated. The results show that for high Rayleigh numbers, a longer fin placing at the middle of the right wall has a more remarkable effect on the flow field and heat transfer inside the cavity.
Effect of inclined thick fin on natural convection in a cavity heated from bottom
Progress in Computational Fluid Dynamics, An International Journal, 2015
In this study, natural convection heat transfer in a square cavity with an adiabatic fin mounted on a vertical wall was investigated numerically. Vertical boundaries were adiabatic and horizontal boundaries were isothermal at different constant temperature. Two-dimensional equations of conservation of mass, momentum and energy were solved using finite difference method. Successive under relaxation (SUR) method was used to solve linear algebraic equations. Results were obtained for various geometrical parameters as the thermal conductivity ratio (RK = 0.1, 1.0 and 10), inclination angle of the fin (30° ≤ φ ≤ 150°), thickness of the fin (0.033 ≤ t ≤ 0.2), and Rayleigh numbers (10 3 ≤ Ra ≤ 10 6). Location and length of fin was fixed as h = w = 0.5. Results were presented with streamlines, isotherms, local and mean Nusselt numbers. It was found that Rayleigh number and the fin mounted on the wall had significant effect on natural convection heat transfer and flow field. The thick fin can be used as control parameter of heat and fluid flow.
Effects of fin on mixed convection heat transfer in a vented square cavity: A numerical study
Mağallaẗ al-qādisiyyaẗ li-l-ʻulūm al-handasiyyaẗ, 2023
Numerical investigation of mixed convective in a vented square cavity with fin. The horizontal walls are adiabatic, while the left and right walls are hot (ℎ) and cold () temperatures, respectively. The fluid inlet to the cavity from the lower left open area(), and exits from the upper right open area (). In this study, a finite element scheme is employed. The analysis is done for specific Prandtl number (= 7), Reynolds number (50 ≤ ≤ 200), fin length (0.2 ≤ ≤ 0.6), Richardson number (0.1 ≤ ≤ 1), and the location of the fin (0.2 ≤ ℎ ≤ 0.6). The finding indicates that the increases when high the location of the fin increases at the maximum height of this fin location is estimated to be 17% due to an increase in the fluid flow area on the hot wall caused by rising convective. The highest heat transfer occurs when the fin length equals 0.6 at the location(ℎ = 0.2).
Heat and Mass Transfer, 2011
Natural convection heat transfer in an inclined fin attached square enclosure is studied both experimentally and numerically. Bottom wall of enclosure has higher temperature than that of top wall while vertical walls are adiabatic. Inclined fin has also adiabatic boundary conditions. Numerical solutions have been done by writing a computer code in Fortran platform and results are compared with Fluent commercial code and experimental method. Governing parameters are Rayleigh numbers (8.105 ≤ Ra ≤ 4 × 106) and inclination angle (30° ≤ and ≤ 120°). The temperature measurements are done by using thermocouples distributed uniformly at the wall of the enclosure. Remarkably good agreement is obtained between the predicted results and experimental data. A correlation is also developed including all effective parameters on heat transfer and fluid flow. It was observed that heat transfer can be controlled by attaching an inclined fin onto wall.
Natural Convection at Different Prandtl Numbers in Rectangular Cavities with a Fin on the Cold Wall
The natural convection in differentially heated rectangular cavities with a fin attached to the cold wall was investigated numerically. The top and the bottom horizontal walls of the cavities were insulated while their left and the right vertical walls were maintained at a constant temperature Th and Tc, respectively with Th > Tc. The governing equations written in terms of the primitive variables were solved numerically using the finite volume method while the velocity and pressure fields were coupled using the SIMPLER algorithm. Using the developed code effects of pertinent parameters such as length and location of fin, aspect ratio of the enclosure, Rayleigh number, and Prandtl number on heat transfer and fluid flow in the enclosure were investigated. The results showed that for the cavity filled with water, at high Rayleigh numbers, a longer fin placing at the middle of the right wall has more remarkable effect on the heat transfer inside the cavity. Also, it was observed tha...
Natural Convection in a Square Cavity with Discrete Heating at the Bottom with Different Fin Shapes
Heat Transfer Engineering, 2017
Numerical study is carried out to investigate the effect of different fin shapes on heating a square cavity by small heating strip located at the bottom wall. The natural convection of air is considered with constant heat flux from heat source which is located at the centre of the bottom wall. The width of the heating strip is assumed to be 20% of the total width of the bottom wall. The remaining (non-heated) part of the bottom wall and the top wall are adiabatic and the side walls are maintained at constant temperature. The investigation considered four shapes of
Purpose – The purpose of this paper is to optimize the heat transfer rate in square cavity by attaching fin at the bottom wall. Design/methodology/approach – The problem is formulated and solved using finite element method. Accuracy of the method is validated by comparisons with previously published work. Findings – It was found that attaching fin reduces heat transfer rate in the cavity. Originality/value – Although the problem is not very original it is important in that many applications have heating on adjacent walls.
International Journal of Engineering Science, 2005
A penalty finite element analysis with bi-quadratic rectangular elements is performed to investigate the influence of uniform and non-uniform heating of wall(s) on natural convection flows in a square cavity. In the present investigation, one vertical wall and the bottom wall are uniformly and non-uniformly heated while the other vertical wall is maintained at constant cold temperature and the top wall is well insulated. Parametric study for a wide range of Rayleigh number (Ra), 10 3 6 Ra 6 10 6 and Prandtl number (Pr), 0.2 6 Pr 6 100 shows consistent performance of the present numerical approach to obtain the solutions as stream functions and temperature profiles. Heat transfer rates at the heated walls are presented in terms of local Nusselt number.
International Journal of Heat and Technology, 2021
An exhaustive numerical investigation is carried out to analyze the role of an isothermal heated thin fin on fluid flow and temperature distribution visualization in an enclosure. Natural convection within square enclosures finds remarkable pragmatic applications. In the present study, a finite difference approach is performed on two-dimensional laminar flow inside an enclosure with cold side walls and adiabatic horizontal walls. The fluid flow equations are reconstructed into vorticity - stream function formulation and these equations are employed utilizing the finite-difference strategy with incremental time steps. The parametric study includes a wide scope of Rayleigh number, Ra, and inclination angle ϴ of the thin fin. The effect of different Rayleigh numbers ranging Ra = 104-106 with Pr=0.71 for all the inclination angles from 0°-360° with uniform rotational length of angle 450 of an inclined heated fin on fluid flow and heat transfer have been investigated. The heat transfer r...
Natural convection and surface radiation heat transfer in a cavity with vertically oriented fins
Materials Today: Proceedings, 2020
In this paper, the finite volume method is combined with the discrete ordinate method to study the natural convection coupled to surface radiation in a cooled square finned cavity. The fin array under consideration is made of N thin fins arranged in a single horizontal row. For better heat transfer performances, all these fins are oriented vertically inside the cavity and heated isothermally at 299K T H 341K. The cavity is filled with air (Pr ¼ 0:71) and cooled by the side vertical walls maintained at a cold temperature T C ¼ 293K. The study investigates the effect of the Rayleigh number ranging from 10 3 to 10 7 , the fins number 1 N 15 and the emissivity 0 e 1. The results are reported in terms of streamlines, isotherms and the local and the average convective and radiative Nusselt numbers. The numerical work is carried out using an in-house CFD code written in FORTRAN. The obtained results show a considerable effect of the surface radiation on the flow structure in the cavity and the maximum rate of heat transfer is reached when the fins number exceeds 9.