HEAT TRANSFER ENHANCEMENT IN PLATES BY NATURAL CONVECTION WITH AND WITHOUT VERTICAL CONFINING WALLS (original) (raw)
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Experimental Setup for Heat Transfer Analysis on Rectangular Plate by Natural Convection
This paper represents the profiled activity accomplished by natural convection and it has the major broad application in the field of engineering and technology. In natural convection the fluid which surrounds the heat source receives heat radiations as its density decreases by temperature gradient as a result the air becomes less dense and forms its provisions for escape and the process continuously takes place for regular intervals, as the cold fluid is made readily available for heat contact and its geometric figure mainly depends on design, and analysis. Thermal analysis is done on the Rectangular flat plate materials used for the process is made of brass which is an alloy of copper and zinc as the brass is non-ferrous metal with excellent electrical and thermal conductivity as well as good corrosion resistance, ductility and strength the thermal conductivity of brass is 109 (w/mk) by which the brass has the excellent thermal conductivity and is a first choice for heat exchangers. The design task of rectangular plate can be accomplished in Catia V5R21 software as it is being end up by making its geometrical model and the thermal behavior is studied in ansys 2020 R1 Academic software Fluent database. CFD analysis is to determine the pressure drop, velocity, heat transfer rate and mass flow rate for the rectangular plate. Thermal analysis is to determine the heat flux and temperature distribution along the rectangular plate. Its post processing gives out the study on contours of various parameters and its values. The charts are prepared by plotting the parameters values on Y axis against the X axis.
Review on Natural Convective Heat Transfer from Inclined Narrow Plates
International Journal for Research in Applied Science & Engineering Technology (IJRASET), 2019
In many engineering situations, the equipment is placed at different geographical locations which are not accessible to regular maintenance and which requires cooling of the surfaces continuously and natural/free convection heat transfer process is preferred for this applications. Natural Convection is one of the major modes of heat transfer that can be classified in terms of being natural, forced, gravitational, granular, or thermomagnetic. In the past decade, several studies on convection heat transfer in much geometry, enhancement of heat transfer by adding narrow strip (fin), effects of the magnetic field in heat transfer, heat transfer in a porous medium have been reported. The effects of Prandtl (Pr), Reynolds (Re), Grashof (Gr), and Rayleigh numbers (Ra), fin length, fin height, fin spacing, and their orientation have also been investigated. This paper reviews various researchers work on fluid flow and heat transfer behavior which is carried out by means different types of fin attachments, their orientation & angle of inclination of the base plate.
Natural Convective Heat Transfer from Inclined Narrow Plates
In many engineering situations, the equipment is placed at different geographical locations which are not accessible to regular maintenance and which requires cooling of the surfaces continuously and natural/free convection heat transfer process is preferred for this applications. Natural Convection is one of the major modes of heat transfer that can be classified in terms of being natural, forced, gravitational, granular, or thermomagnetic. In the past decade, several studies on convection heat transfer in much geometry, enhancement of heat transfer by adding narrow strip (fin), effects of the magnetic field in heat transfer, heat transfer in a porous medium have been reported. The effects of Prandtl (Pr), Reynolds (Re), Grashof (Gr), and Rayleigh numbers (Ra), fin length, fin height, fin spacing, and their orientation have also been investigated. This paper reviews various researchers work on fluid flow and heat transfer behavior which is carried out by means different types of fin attachments, their orientation & angle of inclination of the base plate.
Anbar Journal of Engineering Sciences, 2017
Laminar natural convection heat transfer and fluid flow due to the heating from below at variable heat source length inside two dimensional enclosure has been analyzed numerically in this study. The enclosure has filled with air as a working fluid. The vertical inclined walls of the enclosure are maintained at lower temperature while the remaining walls are insulated. The value of Rayleigh number from (1x10 3 ≤ Ra ≤ 4x10 4), the inclination angle at (γ = 0 o , 22.5 o , 45 o) and dimensionless heat source length at (S = 1 and 0.5). The continuity, momentum and energy equations have been applied to the enclosure and solved by using finite difference method. The results showing that the average Nusselt number increases with the increasing of the heating source length and decreases with the increasing in an inclination angle of the vertical walls.
Natural Convection flow in a vertical channel with internal objects is encountered in several technological applications of particular interest of heat dissipation from electronic circuits, refrigerators, heat exchangers, nuclear reactors fuel elements, dry cooling towers, and home ventilation etc. This study deals with the study of natural convection inside inclined v-slot plate placed in vertical channels. The parameters varied during the experimentation are heat input, aspect ratio (the ratio of length of inclined v-slot plate to the spacing between vertical plates) and elevation of inclined v-slot plate from bottom plate. The present study aims to determine the heat transfer characteristics, temperature distribution along the inclined v-slot plate to develop a correlation in the form of Nu = c (Ra)n for different values of aspect ratio, for the selection of optimum dimension for design purpose. Further, the influences of inclination of plate and aspect ratio on the performance characteristics of heat transfer will be studied.
Natural Convection flow in a vertical channel with internal objects is encountered in several technological applications of particular interest of heat dissipation from electronic circuits, refrigerators, heat exchangers, nuclear reactors fuel elements, dry cooling towers, and home ventilation etc. This study deals with the study of natural convection inside inclined cylinder placed in vertical channels. The parameters varied during the experimentation are heat input, aspect ratio (the ratio of length of inclined cylinder to the spacing between vertical plates) and elevation of inclined cylinder from bottom plate. The present study aims to determine the heat transfer characteristics, temperature distribution along the inclined cylinder to develop a correlation in the form of Nu = c (Ra) n for different values of aspect ratio, for the selection of optimum dimension for design purpose. Further, the influences of aspect ratio on the performance characteristics of heat transfer will be studied and also, the experimental results will be validated with CFD simulation (FLUENT SOFTWARE).
Journal of Heat Transfer-transactions of The Asme, 2008
The analytical solution for a vertical heated plate subjected to conjugate heat transfer due to natural convection at the surface and conduction below is presented. The heated surface is split into two regions; the uniform heat flux region toward upstream and remaining fraction as the uniform wall temperature region. The fractional areas under the two regions are considered variable. Adopting thermally thin wall regime approximation, the possible solutions were investigated and found to satisfactorily deal with longitudinal conduction and temperature variation in the transverse direction. A test setup was developed and the experiments were conducted to obtain relevant data for comparison with the analytical solutions. The ranges for Rayleigh number and heat conduction parameter ͑␣͒ during various test conditions were 2 ϫ 10 8 -6ϫ 10 8 , and 0.001-1, respectively. The limiting solutions for stipulated conditions are analyzed and compared with experimental data. Reasonable agreement is observed between the experimental and analytical results.
The Effect of Plate Size on the Natural Convective Heat Transfer Intensity of Horizontal Surfaces
Heat Transfer Engineering, 2005
Natural convective heat transfer from Jtat horizontal isothermal plates has been investigated for more than a century. In the present study, the infiuence ofthe size ofthe plate on the heat flux is investigated. Two ranges ofthe heat transfer intensity are proposed for this problem, for the plates with characteristic length .smaller than 0.1-0.2 m. the heat transfer coefficient is inversely proportional to the plate width: for plates wider than 0.2 m. the heat fiitx is nol infiuenced by the ptaie width. The explanation for the discrepancy between the two ranges of natural convective heat transfer based on analysis and comparison of e.xperimental data available in the literature has been proposed.
Applied Thermal Engineering, 2007
A numerical investigation was conducted into an alternative method of natural convection enhancement by the transverse oscillations of a thin short plate, strategically positioned in close proximity to a rectangular heat source. The heat source is attached to a mounting board in a vertical channel. Two-dimensional laminar flow finite element studies were carried out with the oscillation parameters, the oscillating plate-heat source mean clearance spacing, and the oscillating plate position varied. Significant cooling was found for displacement amplitudes of at least one-third of the mean clearance together with frequencies ðRe= ffiffiffiffiffi ffi Gr p Þ of over 2p with the displacement being more critical to the cooling level. For the parameters investigated, up to a 52% increase in the local heat transfer coefficient relative to standard natural convection was obtained. The results indicate that this method can serve as a feasible, simpler, more energy and space efficient alternative to common methods of cooling for low power dissipating devices operating at conditions just beyond the reach of pure natural convection.