scholarly journals A REVIEW ON HEAT TRANSFER FROM DIFFERENT SHAPED FINS

2016 ◽  
Vol 2 (2) ◽  
Author(s):  
Abhinandan Jain ◽  
P K Upadhyay ◽  
Jitendra Singh Chouhan
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Rate ◽  
Heat Sink ◽  
Transfer Rate ◽  
Cost Effective ◽  
Industrial Applications ◽  
Heat Sinks ◽  
Manufacturing Cost ◽  
Automotive Components ◽  
Reliable Solution

Heat sinks with fins are generally used to enhance the heat transfer rate in many industrial applications such as cooling of electronic, power electronic, telecommunication and automotive components. In many situations where heat transfer is by natural convection fins offer economical and trouble free solutions. The weight and volume of the equipment are the most important parameters of design. Now days the general trend is to use compact systems especially in electronic field which leads to higher packing density of systems causing higher heat generation. It affects the performance of system and may cause the system failure. The most preferred method for cooling electronic and telecommunications devices is passive cooling since it is cost effective and reliable solution. It doesn’t require costly enhancing devices. This features leads to focus on development of efficient fin heat sink. The important element that defines the geometry of the heat sink is its fins. The fins generally used in industry are straight, circular and pin shaped. The objective of this work is review on the heat transfer rate by different shaped fins in different systems. The proper selection of the interruption length increases the heat transfer rate and in addition providing fin interruptions results in considerable weight reduction that can lead to lower manufacturing cost.

Numerical Simulation of Heat Sink Performance With Interrupted and Staggered Fins

2009 ◽  
Author(s):  
Suabsakul Gururatana ◽  
Xianchang Li
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Reynolds Number ◽  
Heat Transfer Rate ◽  
Heat Sink ◽  
Pressure Loss ◽  
Transfer Rate ◽  
Flow Direction ◽  
Heat Sinks ◽  
High Heat Transfer

Extended surfaces (fins) have been used to enhance heat transfer in many applications. In electronics cooling, fin-based heat sinks are commonly designed so that coolants (gas or liquid) are forced to pass through the narrow straight channel. To improve the overall heat sink performance, this study investigated numerically the details of heat sinks with interrupted and staggered fins cooled by forced convection. Long and narrow flow passages or channels are widely seen in heat sinks. Based on the fundamental theory of heat transfer, however, a new boundary layer can be created periodically with interrupted fins, and the entrance region can produce a very high heat transfer coefficient. The staggered fins can take advantage of the lower temperature flow from the upstream. The tradeoff is the higher pressure loss. A major challenge for heat sink design is to reduce the pressure loss while keeping the heat transfer rate high. The effect of fin shapes on the heat sink performance was also examined. Two different shapes under study are rectangular and elliptic with various gaps between the interrupted fins in the flow direction. In addition, studies were also conducted on the parametric effects of Reynolds number and gap length. It is observed that heat transfer increases with the Reynolds number due to the feature of developing boundary layer. If the same pressure drop is considered, the heat transfer rate of elliptic fins is higher than that of rectangular fins.

scholarly journals Computational Investigation of Micro-channel Heat Sink with Rectangular Shape Obstacles

2021 ◽  
Vol 2070 (1) ◽  
pp. 012181
Author(s):  
P M Wadekar ◽  
A B Shinde ◽  
V B Patil ◽  
P D. Kulkarni ◽  
P V Kengar ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Rate ◽  
Heat Sink ◽  
Transfer Rate ◽  
Heat Sinks ◽  
Micro Channel ◽  
Rectangular Shape ◽  
Numerical Result ◽  
Geometrical Features ◽  
Modeling Software

Abstract Nowadays a lot of interest is given to the geometrical modification of heat sink systems to cool down the electronic components. To improve the performance index of the heat sinks, the use of geometrical features with different shapes and at different locations on the surface can be a valuable approach. In this paper, the effect of rectangular shape obstacles on the micro channel heat sink (MCHS) performance is studied. Due to surface features, vortex is developed which helps to increase the heat transfer rate. Numerical modeling software Comsol Multiphysics with heat transfer in fluid physics is used to investigate the characteristics of a micro-channel heat sink. The numerical result shows that the heat transfer rate can be improved through an appropriate arrangement of rectangular shape obstacles, on the heat sink. Numerical analysis and the comparison is carried out for micro-channel heat sink with and without obstacles. In this paper, various parameters like temperature rise, cell Peclet number and Mean effective thermal conductivity are studied.

Analytic Optimization of Porous Medium Heat Sinks for Energy Efficiency and Minimum Mass

2013 ◽  
Author(s):  
Ninad Trifale ◽  
Eric Nauman ◽  
Kazuaki Yazawa
Keyword(s):  
Heat Transfer ◽  
Energy Efficiency ◽  
Porous Medium ◽  
Heat Transfer Rate ◽  
Heat Sink ◽  
Transfer Rate ◽  
Heat Sinks ◽  
High Heat Flux ◽  
Minimum Mass ◽  
Pumping Power

Use of microchannel heat sinks for high heat flux applications is substantial for thermal management and it is also critical for scalable power generation. For both applications, the energy efficiency consideration of the pump power is crucial. A number of models have been created that predict the performance as a function of the geometrical parameters, taking into account, the pressure loss over the length and volume constraints. Most of the approaches either involve sophisticated calculations incorporating fluid dynamics in channels, or have an analogy with the pin-fin model, which gives simpler calculations but considers only a single laminar flow regime for optimization. Even with the simplified models available, the geometrical impact on mass and pumping power is nonlinear and not apparent for optimization. We propose an optimization of porous medium heat sinks with respect to the heat transfer rate, mass, and pumping power. These are functions of the simplest geometric parameters, i.e. porosity, pore density, and length of the porous medium. Considering large production, mass (cost of raw material) is nearly proportional to the cost of the heat sink, we consider minimizing the mass for indirectly minimizing the overall cost. The other factor for saving energy considered here is the pumping power. This connects to both the heat transfer rate and the power consumption to drive the fluid through the porous medium. The optimization is performed for a specific value of porosity and length of the heat sink. The model considers the effect of flow through the porous medium and the effective thermal conduction as a function of combined conductivity of the solid ligaments and the fluid in pores. An optimum coefficient of performance (COP) is found at over 90% of porosity for minimum mass, pumping work and maximum heat transfer. This mathematical expression of the model will give a quantifiable figure-of-merit to take into account the impact of the mass and the pumping power on the performance to cost ratio.

Cost-Effective Techniques for Enhancing Heat Transfer Rate in Steam Condensation

2005 ◽  
Vol 19 (1) ◽  
pp. 101-105 ◽  
Author(s):  
S. Vemuri ◽  
K. J. Kim ◽  
A. Razani ◽  
T. W. Bell ◽  
B. D. Wood
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Cost Effective ◽  
Steam Condensation ◽  
Enhancing Heat Transfer

Design of a Microfin Array Heat Sink Using Flow-Induced Vibration to Enhance the Heat Transfer Rate in the Laminar Flow Regime

2001 ◽  
Author(s):  
Jeung Sang Go ◽  
Geunbae Lim ◽  
Hayong Yun ◽  
Sung Jin Kim ◽  
Inseob Song
Keyword(s):  
Heat Transfer ◽  
Laminar Flow ◽  
Heat Transfer Enhancement ◽  
Flow Regime ◽  
Heat Transfer Rate ◽  
Heat Sink ◽  
Transfer Rate ◽  
Transfer Enhancement ◽  
Air Velocity ◽  
Flow Induced Vibration

Abstract This paper presented design guideline of the microfin array heat sink using flow-induced vibration to increase the heat transfer rate in the laminar flow regime. Effect of the flow-induced vibration of a microfin array on heat transfer enhancement was investigated experimentally by comparing the thermal resistances of the microfin array heat sink and those of a plain-wall heat sink. At the air velocities of 4.4m/s and 5.5 m/s, an increase of 5.5% and 11.5% in the heat transfer rate was obtained, respectively. The microfin flow sensor also characterized the flow-induced vibration of the microfin. It was determined that the microfin vibrates with the fundamental natural frequency regardless of the air velocity. It was also shown that the vibrating displacement of the microfin is increased with increasing air velocity and then saturated over a certain value of air velocity. Based on the numerical analysis of the temperature distribution resulted from microfin vibration and experimental results, a simple heat transfer model (heat pumping model) was proposed to understand the heat transfer mechanism of a microfin array heat sink. Under the geometric and structural constraints, the maximum heat transfer enhancement was obtained at the intersection of the minimum thickness of the microfin and constraint of the bending angle.

Experimental Investigation on Thermal Performance of Heat Sink With Two Pairs of Embedded Heat Pipes

2007 ◽  
Author(s):  
Hsiang-Sheng Huang ◽  
Jung-Chang Wang ◽  
Sih-Li Chen
Keyword(s):  
Heat Transfer ◽  
Thermal Resistance ◽  
Heat Transfer Rate ◽  
Thermal Performance ◽  
Heat Sink ◽  
Transfer Rate ◽  
Heat Pipes ◽  
Total Heat ◽  
Heating Power ◽  
Total Heat Transfer

This article provides an experimental method to study the thermal performance of a heat sink with two pairs (outer and inner pair) of embedded heat pipes. The proposed method can determine the heat transfer rate of the heat pipes under various heating power of the heat source. A comprehensive thermal resistance network of the heat sink is also developed. The network estimates the thermal resistances of the heat sink by applying the thermal performance test result. The results show that the outer and inner pairs of heat pipes carries 21% and 27% of the total heat transfer rate respectively, while 52% of the heating power is dissipated from the base plate to the fins. The dominated thermal resistance of the heat sink is the base to heat pipes resistance which is strongly affected by the thermal performance of the heat pipes. The total thermal resistance of the heat sink shows the lowest value, 0.23°C/W, while the total heat transfer rate of the heat sink is 140W and the heat transfer rate of the outer and inner pairs of heat pipes is 30W and 38 W, respectively.

Buoyancy-Induced Convection in Metal Foam and Finned Metal Foam Heat Sinks©

2000 ◽  
Author(s):  
A. Bhattacharya ◽  
Roop L. Mahajan
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Metal Foam ◽  
Metal Foams ◽  
Experimental Results ◽  
Heat Sinks ◽  
Normal Metal ◽  
Optimum Number

Abstract In this paper, we present our recent experimental results on buoyancy induced convection in metal foams of different pore densities (corresponding to 5, 10, 20 and 40 pores per inch) and porosities (0.89–0.96). The results show that compared to a hot surface facing up, the heat transfer coefficients in these heat sinks are 5 to 6 times higher. However, when compared to commercially available heat sinks of similar dimensions, the enhancement is found to be marginal. The experimental results also show that for a given pore size, the heat transfer rate increases with porosity suggesting the dominant role played by conduction in enhancing heat transfer. On the other hand, if the porosity is held constant, the heat transfer rate is found to be lower at higher pore densities. This can be attributed to the higher permeability with the larger pores, which allows higher entrainment of air through the porous medium. An empirical correlation, developed for the estimation of Nusselt number in terms of Rayleigh and Darcy numbers, is found to be in good agreement with the experimental data with a maximum error of 10%. We also report our results on novel finned metal foam heat sinks© in natural convection. Experiments were conducted on aluminum foams of 90% porosity with 5 and 20 PPI (pores per inch) with one, two, and four aluminum fins inserted in the foam. All these heat sinks were fabricated in-house. The results show that the finned metal foam heat sinks© are superior in thermal performance compared to the normal metal foam and conventional finned heat sinks. The heat transfer increases with increase in the number of fins. However, the relative enhancement is found to decrease with each additional fin. The indication is that there exists an optimum number of fins beyond which the enhancement in heat transfer due to increased surface area is offset by the retarding effect of overlapping thermal boundary layers. Similar to normal metal foams, the 5 PPI samples are found to give higher values of the heat transfer coefficient compared to the 20 PPI samples due to higher permeability of the porous medium. Future work is planned to arrive at the optimal heat sink configuration for even larger enhancement in heat transfer.

Modeling and Validation of a Prototype Thermally-Enhanced Polymer Heat Exchanger

2011 ◽  
Author(s):  
Frank Robinson ◽  
Juan G. Cevallos ◽  
Avram Bar-Cohen ◽  
Hugh Bruck
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Thermal Loading ◽  
Element Model ◽  
Manufacturing Cost ◽  
Polyamide 12 ◽  
Property Anisotropy ◽  
Injection Molded

Polymer heat exchangers (PHXs) have received considerable attention since their invention more than 40 years ago due to their corrosion resistance, low density and low manufacturing cost. New polymer composites with higher strengths, thermal conductivities and thermal stability promise to bridge the performance gap between polymers and corrosion resistant metals. In the present study, PHX components were injection molded using thermally enhanced polyamide 12 resin and assembled into a crossflow finned-plate heat exchanger prototype. The prototype was implemented in an air-to-water experimental test apparatus and the heat transfer results were compared to an analytical model. This comparison confirmed that a polymer composite heat exchanger (PCHX) can offer significantly enhanced heat transfer relative to a pure polymer. A thermomechanical finite element model of the PCHX was developed and validated using experimental results. At fluid pressures near ambient, the heat transfer rate of the PCHX was 28% less than could be attained with an identical titanium heat exchanger. As fluid pressures increased, the through wall conduction resistance had a larger effect on heat transfer rate, reducing the performance of the PCHX relative to the titanium heat exchanger. Stress analysis of the thermally enhanced PCHX revealed that the stresses due to pressure loading were more sensitive to heat exchanger geometry, while the stresses due to thermal loading were more sensitive to material property anisotropy.

Numerical Studies of a Novel Combined Multiple Shell-Pass Shell-and-Tube Heat Exchanger With Helical Baffles

2008 ◽  
Author(s):  
Qiuwang Wang ◽  
Guidong Chen ◽  
Qiuyang Chen ◽  
Min Zeng ◽  
Dahai Zhang
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Industrial Applications ◽  
The Novel ◽  
Tube Heat Exchanger ◽  
Shell And Tube ◽  
Save Energy ◽  
Cfd Method

In order to simplify the manufacture and improve heat transfer performance of shell-and-tube heat exchangers (STHXs), we have invented a combined multiple shell-pass STHX with continuous helical baffles. The novel combined multiple shell-pass STHX with continuous helical baffles (NOVEL STHX) is compared with the conventional STHX with segmental baffles by Computational Fluid Dynamics (CFD) method. The numerical results show that, under the same mass flow rate M and the same overall heat transfer rate Qm in the shell side, the overall pressure drop DP of the NOVEL STHX is lower than that of the STHX with segmental baffles by about 13%. The heat transfer rate Qm of the NOVEL STHX is higher than that of the STHX with segmental baffles by about 6% under the same overall pressure drop DP. The NOVEL STHX might be used to replace the conventional STHX with segmental baffles in industrial applications to save energy, reduce cost and prolong service life.

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