Improved radial heat sink for led lamp cooling

Abstract

This paper presents a numerical study concerning an improved heat sink for a light emitting diodes (LED) lamp operating under natural convection conditions. Basic geometry of the heat sink is of cylindrical nature, to be obtained from cutting a aluminium extruded bar comprising a cylindrical central core and a number of uniformly distributed radial fins. Minimum diameter of the central core is fixed and the parameters to be explored are the number of fins, their thickness, length (radial dimension) and height. Although not included in the numerical simulations, the thermal resistance due to the use of a thin thermal interface material (TIM) layer between the LED lamp back and the heat sink is taken into account in the analysis. The main objective of the heat sink is to cool the LED lamp so that the lamp maximum temperature at the contact region with the heat sink is maintained below the critical temperature given by the manufacturer. This is a crucial aspect in what concerns the expected lifetime of the LED lamp and should be achieved at the expenses of a as low as possible aluminium mass. Taking these criteria in mind, a design procedure is proposed and followed in the search for the improved heat sink to cool a particular LED lamp. Results obtained with the commercial code ANSYS-CFX clearly show the relative importance of the different governing parameters on the heat sink performance and allow the choice of the better solution within the frame of dimensional constrains. Although the present results concern a particular LED lamp, the proposed methodology can be extended to other types of heat sinks for general light and/or electronic components.

Investigation of natural convection heat transfer around a radial heat sink with a concentric ring

“…It is therefore desirable to investigate natural convection heat transfer via a heat sink with a circular base. Recently, several researchers considered natural convective heat sinks with circular base and rectangular fins [10][11][12][13]. However, configurations of the heat sinks in their study show significant discrepancy with commercially available LED heat sink in that they do not contain concentric rings.…”

Convective heat transfer enhancement by diamond shaped micro-protruded patterns for heat sinks: Thermal fluid dynamic investigation and novel optimization methodology

“…notebook computers, portable devices) in the next future, due to their low cost and reliability. However, the efficiency of these solutions needs to be continuously improved, in order to meet the increasing thermal requirements of next generation electronic devices [6,7].…”

A temperature controller for high power light emitting diodes based on resistive heating and liquid cooling

“…Such a device will produce up to 125 W of heating power, which needs to be dissipated. Despite of the recent improvements for the passive cooling of high power LEDs based on radial heat sinks [11] or heat pipes [12], active cooling will still be the most promising alternative for the most demanding applications. A conclusion has been made that passive cooling for high power luminaires is insufficient and active cooling will most likely be necessary [10].…”