Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Boiling breakthrough: Nano-coating doubles rate of heat transfer

16.02.2012
By adding an incredibly thin coating of alumina to a metal surface, researchers at the Georgia Institute of Technology have doubled the rate that heat travels from a solid surface – such as a pot on a stove – into the liquid in the pot. The results are published in the American Institute of Physics' journal Applied Physics Letters.

Pool boiling is the most common and familiar method of heating a container's contents, and is a remarkably efficient heat transfer method. The transfer of heat in this case is referred to as the "heat flux." There exists, however, a critical point at which a solid surface gets too hot and pool-boiling efficiency is lost.

"Delaying the critical flux could play an important role in advancing thermal management of electronics as well as improving the efficiency of a number of energy systems," says Bo Feng, Ph.D., the Georgia Tech researcher leading this project.

In boiling, bubbles carry away large amounts of heat from solid surfaces, but the bubbles also act as an insulator, preventing the liquid from rewetting the surface and thereby interrupting heat transfer. The alumina coating – only a few hundreds of atoms thick (1/1,000 the thickness of a human hair) – has a high affinity to water and, as a result, facilitates the rapid rewetting of the solid surface.

"This is the primary reason for the enhancement of heat transfer," says Feng. An atomic layer deposition technique was used to control the thickness. By achieving such a thin coating, the additional layer of alumina did not appreciably increase thermal resistance, but it did increase the overall heat transfer.

"The potential contribution of this investigation lies in tailoring the wettability of surfaces at the nanometer scale, thereby greatly increasing the heat transfer during pool boiling," adds G.P. "Bud" Peterson, Ph.D., director of Georgia Tech's Two-Phase Heat Transfer Lab. "This is especially promising for applications where the implementation of nanotube or nanowire arrays are possible."

Nanotube and nanowire arrays are another effective way to enhance pool boiling heat transfer. Combining these two techniques – nanotube and/or nanowire arrays and nano-coating by atomic layer deposition – may increase pool-boiling efficiency even further.

Article: "Enhancement of Critical Heat Flux in Pool Boiling Using Atomic Layer Deposition of Alumina" is published in Applied Physics Letters.

Authors: Bo Feng (1), Keith Weaver (1), and G. P. Peterson (1).

(1) George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Ga.

Charles E. Blue | EurekAlert!
Further information:
http://www.aip.org

More articles from Physics and Astronomy:

nachricht Molecule flash mob
19.01.2017 | Technische Universität Wien

nachricht Magnetic moment of a single antiproton determined with greatest precision ever
19.01.2017 | Johannes Gutenberg-Universität Mainz

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland

19.01.2017 | Earth Sciences

Not of Divided Mind

19.01.2017 | Life Sciences

Molecule flash mob

19.01.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>