Natural and forced convection heat transfer coefficients of various finned heat sinks for miniature electronic systems

Abstract

Downward lighting light-emitting diodes require cooling with cylindrical fin heat sinks to be mounted on top and cooled under natural convection air cooling mode. Performance simulation would involve specification of the heat transfer coefficient. Numerous methods are available to simulate the performance of conventional plate fin heat sinks including computational fluid dynamics packages. It would be feasible to perform simulation based on conventional flat plate fin heat sinks. A cylindrical fin heat sinks could be simply treated as a plate fin heat sink, if we imagine it cut open and laid out horizontally. A theoretical model is proposed in this paper. An experimental investigation is conducted here to validate its accuracy. Convective heat transfer coefficients were experimentally determined for a horizontally and vertically inclined bare plate operating under natural and forced air cooling modes. In addition, a vertical plate fin heat sink and a vertical cylindrical fin heat sink under natural convection were investigated. Power inputs were kept from 5 to 40 W in order to keep operating temperatures below 100 C. Comparison of the experimental heat transfer coefficients and those obtained from well-known existing Nusselt number correlations show that agreement was poor for the bare plate but satisfactory for the plate and cylindrical fin heat sinks. Although they are within the generally accepted range, it would be advisable for actual measurements to be carried out in order to provide more accurate sizing for thermal measurements.

Emerging Trends and Challenges in Thermal Management of Power Electronic Converters: A State of the Art Review

“…The generated heat from the component is accumulated in the conductive surfaces and released to the environment through natural convection [80]. This method only applies to low-power electronic devices due to low heat flux density and is unsuitable for modern power electronic devices [81]. From Figure 32, it can be seen that the natural convection technique has the lowest capacity for heat removal.…”

Experimental and numerical thermal performance analysis with exergy destruction on nanofluid flow in tube with double strip helical screw inserts

“…Heat transfer augmentation is found by Bellos et al 43 with flow of CuO nanofluid in a turbulator with through collector. Pua et al 44 used finned heat sinks to enhance the cooling capacity of miniature electronic cooling systems. Kood et al 45 analyzed thermal hydraulic characteristics of fluid flow in corrugated tubes at turbulent flow regime.…”

A Comprehensive Review on the Core Thermal Management Improvement Concepts in Power Electronics

“…Obviously, thermal interface materials play a key role in such designs [4], and an area increase is the core idea. However, the advances in electronics have necessitated higher cooling capacities making this method incompatible with a majority of more recent designs [5].…”