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 an
aluminum 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 as low as possible aluminum 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.