Computational fluid dynamics of free convection and radiation on thermal performance of light emitting diode applications with trapezoidal-finned heat sink

Abstract

The reduction in energy consumption through the energy performance improvement in the use of artificial lighting system found in all sectors of the economy is one of the very important strategies of achieving sustainable energy development. In contrast to conventional lighting, light-emitting diodes (LEDs) provide better energy efficiency. To effectively optimize the performance and efficiency of the LED lighting, the LED heat needs to be dissipated adequately. In the present work, the cooling performance of a radial heat sink with trapezoidal fins is numerically investigated under the consideration of natural convection and radiation. The study investigated the influence of the number of fins (20≤Nf≤36), the height of the fins (15mm≤hfH≤35mm) and the applied heat flux (300W/m2≤q˙≤1100W/m2) on the thermal resistance (Rth) and heat transfer coefficient (havg) of the heat sink. The numerical results obtained from this work were validated with literature, and an excellent agreement was established. The results found that both the Rth and the havg of the heat sink decreased as the number of fins (Nf) and fin height (hfH) increased. Meanwhile, the number of fins (Nf) has an optimal value for achieving the heat sink's effective cooling performance.

Keywords

• Radial heat sink
• LED
• Radiation heat transfer
• Natural convection
• Computational fluid dynamics
• Cooling