scholarly journals Selective Laser Melting Heat Sinks under Jet Impingement Cooling for Heat Dissipation of Higher Light Output LED Lighting in a Limited Space

2020 ◽  
Vol 10 (11) ◽  
pp. 3898
Author(s):  
Yi-Cheng Huang ◽  
Huan-Chu Hsu
Keyword(s):  
Heat Transfer ◽  
Selective Laser Melting ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Light Output ◽  
Jet Impingement ◽  
Heat Sinks ◽  
Laser Melting ◽  
Impingement Cooling ◽  
Led Lighting

In this study, we aimed to create heat sinks with higher heat dissipation capabilities for a compact light-emitting diode (LED) recessed downlight (CLRDL) under jet impingement cooling. We desired to use the sinks in limited space to maintain lower junction temperature and allow higher LED power. Perforated-finned heat sinks (PTFHSs) and metal-foam-like heat sinks (MFLHSs) fabricated using selective laser melting (SLM) were compared with a traditional finned heat sink (TTFHS). Two cooling fans with higher and lower velocity at Reynolds numbers of 16916 and 6594 were individually installed on each heat sink. Numerical simulations were performed using COMSOL rotating machinery and nonisothermal flow interface with the standard k-ε turbulence flow model. Validations were performed on this apparatus. The SLM heat sinks exhibited higher Nusselt numbers and lower thermal resistance than traditional heat sinks because of a relatively higher heat transfer coefficient and larger heat transfer area. For the proposed SLM heat sinks with larger surface areas, complex flow channels, and ventilation holes under jet impingement cooling, the PTFHS exhibited the highest heat transfer enhancement followed by MFLHS and TTFHS. The results contribute to solving the problems of heat dissipation of higher light output LED lighting.

scholarly journals Numerical Optimization of a Microchannel Geometry for Nanofluid Flow and Heat Dissipation Assessment

2021 ◽  
Vol 11 (5) ◽  
pp. 2440
Author(s):  
Inês M. Gonçalves ◽  
César Rocha ◽  
Reinaldo R. Souza ◽  
Gonçalo Coutinho ◽  
Jose E. Pereira ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Jet Impingement ◽  
Experimental Tests ◽  
Heat Sinks ◽  
Working Fluid ◽  
Optimized Design ◽  
Nanofluid Flow ◽  
Microchannel Heat Sinks

In this study, a numerical approach was carried out to analyze the effects of different geometries of microchannel heat sinks on the forced convective heat transfer in single-phase flow. The simulations were performed using the commercially available software COMSOLMultiphysics 5.6® (Burlington, MA, USA) and its results were compared with those obtained from experimental tests performed in microchannel heat sinks of polydimethylsiloxane (PDMS). Distilled water was used as the working fluid under the laminar fluid flow regime, with a maximum Reynolds number of 293. Three sets of geometries were investigated: rectangular, triangular and circular. The different configurations were characterized based on the flow orientation, type of collector and number of parallel channels. The main results show that the rectangular shaped collector was the one that led to a greater uniformity in the distribution of the heat transfer in the microchannels. Similar results were also obtained for the circular shape. For the triangular geometry, however, a disturbance in the jet impingement was observed, leading to the least uniformity. The increase in the number of channels also enhanced the uniformity of the flow distribution and, consequently, improved the heat transfer performance, which must be considered to optimize new microchannel heat sink designs. The achieved optimized design for a heat sink, with microchannels for nanofluid flow and a higher heat dissipation rate, comprised a rectangular collector with eight microchannels and vertical placement of the inlet and outlet.

Thermal Performance of Mini-Scale Heat Sink With Jet Impingement and Roughened Surface

2016 ◽  
Author(s):  
Zhongyang Shen ◽  
Qi Jing ◽  
Yonghui Xie ◽  
Di Zhang
Keyword(s):  
Heat Transfer ◽  
Thermal Performance ◽  
Heat Sink ◽  
Jet Impingement ◽  
Feature Size ◽  
Impingement Cooling ◽  
Heat Transfer Augmentation ◽  
Roughened Surface ◽  
And Performance ◽  
Set Up

Cooling technique in mini-scale heat sink is essential with the development of high power electronics such as electronic chip. As heat transfer techniques, jet impingement cooling and convective cooling by roughened surface are commonly adopted. To obtain good cooling efficiency, the cooling structure within the heat sink should be carefully designed. In the present study, mini-scale heat sink with feature size of 1∼10 mm is set up. Arrangement of jet impingement and dimple/protrusion surface are designed as heat transfer augmentation approaches. The effect of dimple/protrusion configuration is discussed. From the result, the Nu distribution of on heat sink surface is demonstrated for each case. The pressure penalty due to the arrangement of roughened structure is evaluated. Also, thermal performance TP and performance evaluation plot are adopted as evaluations of cooling performance for each configuration. Comparing all cases, optimal cooling structure considering the energy saving performance is obtained for the mini-scale heat sink. Referencing the statistics, new insight has been provided for the design of cooling structure inside mini-scale heat sink.

Effect of Synthetic Jets Over Natural Convection Heat Sinks

2008 ◽  
Author(s):  
Mehmet Arik ◽  
Yogen Utturkar ◽  
Murat Ozmusul
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Synthetic Jet ◽  
Synthetic Jets ◽  
Operating Conditions ◽  
Heat Sinks ◽  
Junction Temperature ◽  
Allowable Limit

In moderate power electronics applications, the most preferred way of thermal management is natural convection to air with or without heat sinks. Though the use of heat sinks is fairly adequate for modest heat dissipation needs, it suffers from some serious performance limitations. Firstly, a large volume of the heat sink is required to keep the junction temperature at an allowable limit. This need arises because of the low convective film coefficients due to close spacing. In the present computational and experimental study, we propose a synthetic jet embedded heat sink to enhance the performance levels beyond two times within the same volume of a regular passive heat sink. Synthetic jets are meso-scale devices producing high velocity periodic jet streams at high velocities. As a result, by carefully positioning of these jets in the thermal real estate, the heat transfer over the surfaces can be dramatically augmented. This increase in the heat transfer rate is able to compensate for the loss of fin area happening due to the embedding of the jet within the heat sink volume, thus causing an overall increase in the heat dissipation. Heat transfer enhancements of 2.2 times over baseline natural convection cooled heat sinks are measured. Thermal resistances are compared for a range of jet operating conditions and found to be less than 0.9 K/W. Local temperatures obtained from experimental and computational agreed within ± 5%.

Pressure Loss and Heat Transfer Through Heat Sinks Produced by Selective Laser Melting

2009 ◽  
Vol 30 (13) ◽  
pp. 1068-1076 ◽  
Author(s):  
Matthew Wong ◽  
Ieuan Owen ◽  
Chris J. Sutcliffe
Keyword(s):  
Heat Transfer ◽  
Selective Laser Melting ◽  
Pressure Loss ◽  
Heat Sinks ◽  
Laser Melting

Enhanced Heat Transfer in Radial Heat Sinks for LED Lamps

2018 ◽  
Author(s):  
Fernando Cano-Banda ◽  
Ana Gallardo-Gutierrez ◽  
Jesus Garcia-Gonzalez ◽  
Abel Hernandez-Guerrero ◽  
Luis Luviano-Ortiz
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Heat Sinks ◽  
Output Analysis ◽  
Maximum Heat ◽  
Maximum Heat Transfer ◽  
Longitudinal Orientation ◽  
Radial Heat

A radial design of a passive heat sink for cooling LED illumination devices is analyzed numerically in order to identify the geometric shape that promotes better heat dissipation rates. Natural convection with the surrounding is considered during the operation of the heat sink. Due to the fact that natural convection is the main mechanism of heat transfer, the shape of the heat sink has a high influence in the heat dissipated. An analysis of the influence of different parameters of a heat sink is conducted in the presented study. The radial heat sink under analysis consists in a flat disc with rectangular fins on it, and the fins are distributed with a radial longitudinal orientation in a circular row arrangement. The number of rows can vary but there is a constant relation of two times the number of fins between the number of fins in an inner row and the next outer row. In order to find a correct configuration to improve the dissipation of heat, parameters like the number of fins, the length of the fins and the separation between fins are studied. The average Nusselt number and thermal resistance for each geometric configuration are compared. The output analysis provides the best shape for a maximum heat transfer.

Impinging Jet Cooled Plate Fin Heat Sinks With Turbulators Enhancement

2009 ◽  
Author(s):  
Ganesh Subbuswamy ◽  
Xianchang Li
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Heat Sink ◽  
Numerical Study ◽  
Turbine Blades ◽  
Jet Impingement ◽  
Impinging Jet ◽  
Impinging Jets ◽  
Heat Sinks ◽  
Internal Cooling

Extended surfaces (fins) and impinging jets have been used to enhance heat transfer in many applications. In electronic thermal management, heat sinks can be designed to take advantage of the combined effect of fins and jet impingement such as jets impinging on an array of pin fins or plate fins. Significant studies have been focused on the thermal resistance, pressure drop, and the parametric effect of Reynolds number, fin thickness, density, and height. To further improve the heat sink performance, ribs/turbulators, which are widely employed in internal cooling of gas turbine blades, can be integrated into the plate fins, especially close to the surface area with low heat transfer coefficient. Numerical study is performed in this paper to examine the flow and heat transfer behavior of plate fin heat sinks cooled by an impinging jet and enhanced by the ribs. The height and shape of the turbulators are investigated to achieve the best performance. Parametric studies also include the flow Reynolds number and the spacing between the ribs. Heat transfer mechanism is explored for the confined turbulence jet with and without turbulators. It is expected that the rib enhancement can lead to a more cost-effective heat sink for cooling of electronic components. Further enhancement and optimization are discussed in this paper.

Thermal Performance Exploration of Air Foil Shape of Pillars using Impinging Jet in Heat Sink

2021 ◽  
Vol 7 (5) ◽  
pp. 2794-2807
Author(s):  
Deepak Kumar ◽  
Mohammad Zunaid ◽  
Samsher Gautam
Keyword(s):  
Heat Transfer ◽  
Thermal Performance ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Jet Impingement ◽  
Constant Heat Flux ◽  
Diameter Ratio ◽  
Heat Transfer Augmentation ◽  
The Heat Transfer Coefficient ◽  
Selection Of

Objectives: The current investigation introduces the concept of heat sink with combination of jet impingement, micro – channel and air foil shaped pillars. A numerical model is designed to explore the thermal performance of jet impingement with constant heat flux. The steady state conditions are assumed for the laminar and incompressible flow. For the purpose of study dimensionless variables are formed. The performance of jet impingement was predicted in terms of different parameters like temperature rise, drop in pressure and coefficient of heat transfer. Augmentation in pitch diameter ratio, leads to increase in temperature for a particular value of height diameter ratio. Also the heat transfer coefficient gets lowered with the increase in pitch diameter ratio. So proper selection of dimensionless parameters to increase the heat dissipation is of utmost importance.

A Study on the Fluid Flow and Heat Transfer for a Porous Architected Heat Sink Using the Idea of CFD Modelling

2019 ◽  
Author(s):  
Mohamed I. Hassan Ali ◽  
Oraib Al-Ketan ◽  
Nada Baobaid ◽  
Kamran Khan ◽  
Rashid K. Abu Al-Rub
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Fluid Flow ◽  
Transfer Coefficient ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Heat Sinks ◽  
Cooling Power ◽  
Cfd Modelling ◽  
The Heat Transfer Coefficient

Abstract The drive for small and compact electronic components with higher processing capabilities is limited by their ability to dissipate the associated heat generated during operations. Therefore, these components are equipped with heat sinks to facilitate the dissipation of thermal energy. The emergence of additive manufacturing (AM) allowed for new degrees of freedom in terms of design and eliminated the need for excessive tooling that is associated with the conventional manufacturing processes. As such, AM facilitated the development of geometrically complex heat sinks that are capable of capitalizing on topological aspects to enhance their performance. The main objective of this study is to propose and develop architected heat sinks. We propose the use of heat sinks with topologies based on triply periodic minimal surfaces (TPMS). 3D CFD models are developed using Starccm+ platform for three architected heat sinks to study the heat transfer coefficient and surface temperature in free convection heat transfer domains. The heat dissipation versus the input heat sources as well as the heat transfer coefficient will be used for measuring the heat sink performance. The required fluid flow rate and pressure drop will be used to measure the required cooling power for the proposed heat sinks.

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