Placement of Heated Blocks Under Forced Convection for Enhanced Heat Transfer

2020 ◽  
pp. 59-65
Author(s):  
Shankar Durgam ◽  
Shakkottai Venkateshan ◽  
Thirumalachari Sundararajan ◽  
Milankumar Nandgaonkar ◽  
Pravin D. Sawarkar ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Forced Convection ◽  
Enhanced Heat Transfer

Enhanced Heat Transfer Through the Use of Nanofluids in Forced Convection

2004 ◽  
Author(s):  
Daniel J. Faulkner ◽  
David R. Rector ◽  
Justin J. Davidson ◽  
Reza Shekarriz
Keyword(s):  
Heat Transfer ◽  
Turbulent Flow ◽  
Convective Heat Transfer ◽  
Flow Regime ◽  
Forced Convection ◽  
Convective Heat ◽  
Reynolds Numbers ◽  
Enhanced Heat Transfer ◽  
Low Reynolds Numbers ◽  
Turbulent Flow Regime

Much attention has been paid in recent years to the use of nanoparticle suspensions for enhanced heat transfer. The majority of this work has focused on the thermal conductivity of these nanofluids, which can be as much as 2.5 times higher than that of the plain base fluid. The present work moves beyond measurements of non-flowing liquids, to explore the role that nanofluids can play in enhancing convective heat transfer within microscale channels. A unique pseudo-turbulent flow regime is postulated, which simulates turbulent behavior at very low Reynolds numbers, in what are nominally laminar flows. The resulting fluid mixing has the potential to raise the average convective heat transfer coefficient within the channel. Numerical modeling, using the lattice Boltzmann method, confirms the existence of the pseudo-turbulent flow regime. Finally, experimental results are presented which demonstrate a significant heat transfer enhancement when using nanofluids in forced convection. The current results are especially relevant to microchannel heatsinks, where the low Reynolds numbers impose limitations on the maximum Nusselt number achievable.

Enhanced Heat Transfer Using Porous Carbon Foam in Cross Flow—Part I: Forced Convection

2006 ◽  
Vol 129 (6) ◽  
pp. 735-742 ◽  
Author(s):  
Yorwearth L. Jamin ◽  
Abdulmajeed A. Mohamad
Keyword(s):  
Heat Transfer ◽  
Forced Convection ◽  
Heat Exchangers ◽  
Cross Flow ◽  
Carbon Foam ◽  
Industrial Processes ◽  
Transfer Enhancement ◽  
Vertical Pipe ◽  
Enhanced Heat Transfer ◽  
Flow Part

Cogeneration of heat and power has become standard practice for many industrial processes. Research to reduce the thermal resistance in heat exchangers at the gas/solid interface can lead to greater energy efficiency and resource conservation. The main objective of this experimental study is to quantify and compare the heat transfer enhancement of carbon foam and aluminum fins. The study measures the heat transfer rate and pressure drop from a heated vertical pipe, with and without porous medium, in forced convection. The largest increase in Nusselt number was achieved by aluminum fins, which was about three times greater than the best carbon foam case.

An Attempt to Experimentally Uncouple the Effect of Coriolis and Buoyancy Forces on Heat Transfer in Smooth Circular Tubes Which Rotate in the Orthogonal Mode

1991 ◽  
Author(s):  
W. D. Morris ◽  
R. Salemi
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Experimental Investigation ◽  
Forced Convection ◽  
Circular Tube ◽  
Leading Edge ◽  
Enhanced Heat Transfer ◽  
Coriolis Forces ◽  
Circular Tubes ◽  
Buoyancy Forces

This paper reports the results of an experimental investigation of the combined effect of Coriolis and buoyancy forces on forced convection in a circular tube which rotates about an axis orthogonal to its centre line. The experiment has been deliberately designed to minimise the effect of circumferential conduction in the tube walls by using material of relatively low thermal conductivity. A new correlating parameter for uncoupling the effect of Coriolis forces from centripetal buoyancy is proposed for the trailing and leading edges of the tube. It is demonstrated that enhanced heat transfer on the trailing edge occurs as a result of rotation. On the leading edge significant reductions in heat transfer compared to the zero rotation case can occur but with possible recovery at high rotational speeds.

Active Upstream Components for Enhanced Heat Transfer of Longitudinally Finned Heat Sinks

2010 ◽  
Author(s):  
John Daly
Keyword(s):  
Heat Transfer ◽  
Forced Convection ◽  
Heat Sink ◽  
Performance Enhancement ◽  
Heat Sinks ◽  
Air Cooling ◽  
Active Components ◽  
Enhanced Heat Transfer ◽  
Current Standard ◽  
Piezoelectric Fans

With the ever increasing heat flux from next-generation chips forced convection cooling is beginning to reach its limits within current standard heat sink capabilities. Methods of extending the air cooling capabilities prior to a transition to liquid or refrigerant-based cooling which is seen as costly and complex, have become more critical. This paper investigates the enhanced heat transfer by the addition of active components upstream of a longitudinally finned heat sink. This paper addresses piezoelectric fans for natural and forced convection environments. Experimental measurements are taken for a low powered DC fan operating at a frequency of 114Hz. For the forced convection experiments a fully ducted flow was used. The main thrust of the paper is to determine the effects of piezoelectrics in augmenting forced convection systems at hot component locations. The effects on pressure drop, thermal resistance and pumping power with the addition of the technology are presented. The paper concludes by reporting on the performance enhancement and limitations of the piezoelectric fans compared to the conventional longitudinally finned heat sink geometry.

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