Investigation of Maximum Heat Transfer from an Aluminum Alloy Extended Surfaces

Author(s):  
Raad Muzahem Fenjan

The aim of this research is to obtain the maximum steady state heat transfer used aluminum alloy extended surfaces which obtain the optimal design for these fins. For three cases, (according to both dimension and direction of the extended surfaces): vertical fins extended from horizontal base, vertical fins extended from vertical base , and horizontal fins extended from vertical base, the natural convective, conductive and radiative heat transfer was studied experimentally and respectively the comparison between these cases were achieved.  The parameters studied were distance between fins, fin length fin thickness and fin protrusion.

2005 ◽  
Author(s):  
Benjamin A. Blake ◽  
Ivan Catton

A parallel plate heat sink is optimized using a model based on the volume average theory (VAT). VAT is briefly developed and the numerical scheme is described. The numerical simulation is carried out in FORTRAN. The resulting VAT solutions are verified by comparison to experimental results via a Nusselt number correlation. The procedure for optimization is described and, as an example, a heat sink of a size appropriate for cooling a CPU is optimized for minimum thermal resistance, maximum effectiveness, and maximum heat transfer rate per unit volume. Seven parameters are included in the simulations: fin thickness, fin length, fin height, fin pitch to thickness ratio, base width, base thickness, and pore Reynold’s number. Three are chosen for optimization: fin height, fin pitch, and pore Reynolds number. The responses are optimized for an aluminum heat sink.


1996 ◽  
Vol 118 (3) ◽  
pp. 570-577 ◽  
Author(s):  
G. Ledezma ◽  
A. M. Morega ◽  
A. Bejan

This is an experimental numerical and theoretical study of the heat transfer on a pin-finned plate exposed to an impinging air stream. The pin fins are aligned with the air approach velocity. The base plate and the fin cross section are square. It is demonstrated experimentally that the thermal conductance between the plate and the air stream can be maximized by selecting the fin-to-fin spacing S. Next, a simplified numerical model is used to generate a large number of optimal spacing and maximum heat transfer data for various configurations, which differ with respect to fin length (H), fin thickness (D), base plate size (L), fluid type (Pr), and air velocity (ReL). Finally, the behavior of the optimal spacing data is explained and correlated theoretically based on the intersection of asymptotes method. The recommended correlations for optimal spacing, Sopt/L ≅ 0.81 Pr−0.25 ReL−0.32, and maximum thermal conductance, (q/ΔT)max/kaH ≅ 1.57 Pr0.45 ReL0.69 (L/D)0.31, cover the range D/L = 0.06 − 0.14, H/L = 0.28−0.56, Pr = 0.72−7, ReD = 10−700, and ReL = 90−6000.


2013 ◽  
Vol 446-447 ◽  
pp. 146-150
Author(s):  
Hui Wang ◽  
Hai Bo Yang

For the 6063 aluminum alloy spray quenching process, respectively establish finite element model of upper, lower nozzle jet impact and water area and meshing in the Gambit. Import into fluent software for cooling numerical simulation, getting the upper and lower nozzle’s pressure contours , velocity contours , heat transfer coefficient curve and water area’s velocity contours and heat transfer coefficient curves. Analysis the various contours and the heat transfer coefficient along the aluminum plate surface radial distribution: upper nozzle’s heat transfer intensity is not in stationary point and near its both sides; Lower nozzle’s contours and heat transfer coefficient has a certain similarity with the upper nozzle, but the maximum heat transfer intensity is at stagnation point; Water area‘s heat transfer coefficient fall faster at the entrance and maintained at a constant value finally. Put heat transfer coefficient as a boundary condition into the ansys software to simulate the three dimensional temperature field of quenching process and analysis the temperature field contours in different time: the biggest speed is 36°C/s during the process of quenching, appearing in the high temperature range, namely deformation sensitive areas, therefore it most likely to occur deformation at the beginning of the quenching profiles.


2019 ◽  
Vol 7 (1) ◽  
pp. 43-53
Author(s):  
Abbas Jassem Jubear ◽  
Ali Hameed Abd

The heat sink with vertically rectangular interrupted fins was investigated numerically in a natural convection field, with steady-state heat transfer. A numerical study has been conducted using ANSYS Fluent software (R16.1) in order to develop a 3-D numerical model.  The dimensions of the fins are (305 mm length, 100 mm width, 17 mm height, and 9.5 mm space between fins. The number of fins used on the surface is eight. In this study, the heat input was used as follows: 20, 40, 60, 80, 100, and 120 watts. This study focused on interrupted rectangular fins with a different arrangement and angle of the fins. Results show that the addition of interruption in fins in various arrangements will improve the thermal performance of the heat sink, and through the results, a better interruption rate as an equation can be obtained.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3827
Author(s):  
Marek Klimczak ◽  
Witold Cecot

In this paper, we present a new approach to model the steady-state heat transfer in heterogeneous materials. The multiscale finite element method (MsFEM) is improved and used to solve this problem. MsFEM is a fast and flexible method for upscaling. Its numerical efficiency is based on the natural parallelization of the main computations and their further simplifications due to the numerical nature of the problem. The approach does not require the distinct separation of scales, which makes its applicability to the numerical modeling of the composites very broad. Our novelty relies on modifications to the standard higher-order shape functions, which are then applied to the steady-state heat transfer problem. To the best of our knowledge, MsFEM (based on the special shape function assessment) has not been previously used for an approximation order higher than p = 2, with the hierarchical shape functions applied and non-periodic domains, in this problem. Some numerical results are presented and compared with the standard direct finite-element solutions. The first test shows the performance of higher-order MsFEM for the asphalt concrete sample which is subject to heating. The second test is the challenging problem of metal foam analysis. The thermal conductivity of air and aluminum differ by several orders of magnitude, which is typically very difficult for the upscaling methods. A very good agreement between our upscaled and reference results was observed, together with a significant reduction in the number of degrees of freedom. The error analysis and the p-convergence of the method are also presented. The latter is studied in terms of both the number of degrees of freedom and the computational time.


Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2069
Author(s):  
Eloy Hontoria ◽  
Alejandro López-Belchí ◽  
Nolberto Munier ◽  
Francisco Vera-García

This paper proposes a methodology aiming at determining the most influent working variables and geometrical parameters over the pressure drop and heat transfer during the condensation process of several refrigerant gases using heat exchangers with pipes mini channels technology. A multi-criteria decision making (MCDM) methodology was used; this MCDM includes a mathematical method called SIMUS (Sequential Interactive Modelling for Urban Systems) that was applied to the results of 2543 tests obtained by using a designed refrigeration rig in which five different refrigerants (R32, R134a, R290, R410A and R1234yf) and two different tube geometries were tested. This methodology allows us to reduce the computational cost compared to the use of neural networks or other model development systems. This research shows six variables out of 39 that better define simultaneously the minimum pressure drop, as well as the maximum heat transfer, saturation pressure fluid entering the condenser being the most important one. Another aim of this research was to highlight a new methodology based on operation research for their application to improve the heat transfer energy efficiency and reduce the CO2 footprint derived of the use of heat exchangers with minichannels.


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