Student Heat Sink Design Challenge

In this paper, two most prevalent topological optimisation approaches namely Density and Level set method are applied to a three dimensional heat sink design problem. The relative performance of the two approaches is compared in terms of design quality, robustness and computational speed. The work is original as for the first time it demonstrates the relative advantages and disadvantages for each method when applied to a practical engineering problem. It is additionally novel in that it presents the design of a convectively cooled heat sink by solving full thermo-fluid equations for two different solid-fluid material sets. Further, results are validated using a separate computational fluid dynamics study with the optimised designs are compared against a standard pin-fin-based heat sink design. The results show that the Density method demonstrates better performance in terms of robustness and computational speed, while Level-set method yields a better quality design in terms of final objective value.

Download Full-text

Thermo-economic Limitations of Ambient Heat Rejection in Vertical Fin Arrays With Buoyancy-Driven Flow Enhancement Through the Chimney Effect

Journal of Thermal Science and Engineering Applications ◽

10.1115/1.4034338 ◽

2016 ◽

Vol 9 (1) ◽

Author(s):

Noris Gallandat ◽

J. Rhett Mayor

Keyword(s):

Heat Flux ◽

Heat Sink ◽

Cooling Power ◽

Heat Rejection ◽

One Dimensional ◽

Power Enhancement ◽

Flow Enhancement ◽

The Cost ◽

Heat Sink Design ◽

Chimney Effect

This paper presents the thermo-economic limits of ambient heat rejection in vertical fin arrays with buoyancy-driven flow enhancement through the chimney effect. A one-dimensional semi-analytical thermo-fluidic model is developed to assess the cooling power enhancement of the proposed heat sink design. A bi-objective optimization is performed utilizing genetic algorithm to present the tradeoffs between the cost and the thermal performance of a heat sink. For the considered baseplate geometry, the maximal cooling power without a chimney amounts 1540 W at a heat flux of 1.03 W/cm2. By adding a chimney up to 2.5 m high, the cooling power is increased by 46% to 2250 W at a heat flux of 1.50 W/cm2.

Download Full-text

A Numerical and Experimental Study of a Novel Heat Sink Design for Natural Convection Cooling of LED Grow Lights

Energies ◽

10.3390/en13164046 ◽

2020 ◽

Vol 13 (16) ◽

pp. 4046

Author(s):

Ram Adhikari ◽

Dawood Beyragh ◽

Majid Pahlevani ◽

David Wood

Keyword(s):

Heat Transfer ◽

Natural Convection ◽

Heat Sink ◽

Large Scale ◽

High Efficiency ◽

Experimental Testing ◽

Growth Stages ◽

Air Cooling ◽

Convection Cooling ◽

Heat Sink Design

Light-emitting diode (LED) grow lights are increasingly used in large-scale indoor farming to provide controlled light intensity and spectrum to maximize photosynthesis at various growth stages of plants. As well as converting electricity into light, the LED chips generate heat, so the boards must be properly cooled to maintain the high efficiency and reliability of the LED chips. Currently, LED grow lights are cooled by forced convection air cooling, the fans of which are often the points of failure and also consumers of a significant amount of power. Natural convection cooling is promising as it does not require any moving parts, but one major design challenge is to improve its relatively low heat transfer rate. This paper presents a novel heat sink design for natural convection cooling of LED grow lights. The new design consists of a large rectangular fin array with openings in the base transverse to the fins to increase air flow, and hence the heat transfer. Numerical simulations and experimental testing of a prototype LED grow light with the new heat sink showed that openings achieved their intended purpose. It was found that the new heat sink can transfer the necessary heat flux within the safe operating temperature range of LED chips, which is adequate for cooling LED grow lights.

Download Full-text

Thermal Analysis of Miniature Low Profile Heat Sinks With and Without Fins

Journal of Electronic Packaging ◽

10.1115/1.3144150 ◽

2009 ◽

Vol 131 (3) ◽

Cited By ~ 12

Author(s):

V. Egan ◽

P. A. Walsh ◽

E. Walsh ◽

R. Grimes

Keyword(s):

Heat Transfer ◽

Heat Sink ◽

Volume Flow Rate ◽

Electronic Devices ◽

Heat Fluxes ◽

Heat Sinks ◽

Superior Performance ◽

Low Profile ◽

In Series ◽

Heat Sink Design

Reliable and efficient cooling solutions for portable electronic devices are now at the forefront of research due to consumer demand for manufacturers to downscale existing technologies. To achieve this, the power consumed has to be dissipated over smaller areas resulting in elevated heat fluxes. With regard to cooling such devices, the most popular choice is to integrate a fan driven heat sink, which for portable electronic devices must have a low profile. This paper presents an experimental investigation into such low profile cooling solutions, which incorporate one of the smallest commercially available fans in series with two different heat sink designs. The first of these is the conventionally used finned heat sink design, which was specifically optimized and custom manufactured in the current study to complement the driving fan. While the second design proposed is a novel “finless” type heat sink suitable for use in low profile applications. Together the driving fan and heat sinks combined were constrained to have a total footprint area of 465 mm2 and a profile height of only 5 mm, making them ideal for use in portable electronics. The objective was to evaluate the performance of the proposed finless heat sink design against a conventional finned heat sink, and this was achieved by means of thermal resistance and overall heat transfer coefficient measurements. It was found that the proposed finless design proved to be the superior cooling solution when operating at low fan speeds, while at the maximum fan speed tested of 8000 rpm both provided similar performance. Particle image velocimetry measurements were used to detail the flow structures within each heat sink and highlighted methods, which could further optimize their performance. Also, these measurements along with corresponding global volume flow rate measurements were used to elucidate the enhanced heat transfer characteristics observed for the finless design. Overall, it is shown that the proposed finless type heat sink can provide superior performance compared with conventional finned designs when used in low profile applications. In addition a number of secondary benefits associated with such a design are highlighted including lower cost, lower mass, lower acoustics, and reduced fouling issues.

Download Full-text