Featured Research

from universities, journals, and other organizations

Fire On The Move

Date:
September 11, 1998
Source:
Weizmann Institute
Summary:
Fire is a formidable foe, its destructive power usually advancing rapidly in chaotic patterns. Now, Weizmann Institute of Science researchers have brought fire under control in the laboratory, revealing that under certain conditions, a weak but persistent flame can advance undetected, wreaking havoc on Earth... and in space.

Fire is a formidable foe, its destructive power usually advancing rapidly in chaotic patterns. Now, Weizmann Institute of Science researchers have brought fire under control in the laboratory, revealing that under certain conditions, a weak but persistent flame can advance undetected, wreaking havoc on Earth... and in space.

Flame is notoriously difficult to study because it is rendered chaotic by convection, a phenomenon in which hot gas rises. To eliminate convection-induced complexity, Dr. Ory Zik and Prof. Elisha Moses of the Institute's Physics of Complex Systems Department "squeezed" fire into two dimensions. In their experiment, soon to be reported in PHYSICAL REVIEW LETTERS, fire propagates in a controllable manner through a sheet of paper contained in a transparent case, leaving behind a pattern of long, finger-like projections. The scientists controlled the propagation rate and the density of the fingers by adjusting the oxygen supply.

Much to their surprise, they discovered that flame dynamics are governed by the same laws that describe more stable phenomena -- for example, penetration of a liquid into a porous material. Since these laws are relatively simple, it is a real boon for scientists to know that they can also be applied to systems as unstable as fire. The theory to explain the phenomenon was developed with the help of Dr. Zeev Olami of the Chemical Physics Department.

Interestingly, at about the same time as this study, NASA's scientists launched an experiment aboard the space shuttle to examine the way fire spreads in outer space. They were amazed to discover that their flames advanced slowly but steadily like a fiery monster with finger-like projections. The NASA researchers approached the Weizmann scientists, who provided a simple explanation to this puzzling phenomenon: The astronauts had observed exactly the same finger-like pattern as in the Institute experiment, only in three dimensions. In both cases, the key element was the absence of convection. While on Earth convection was neutralized by creating a 2-D system, in space, convection was absent because in zero-gravity hot air doesn't rise.

Thus, the Weizmann experiment provides a low-cost terrestrial alternative to studying the spread of fire aboard spacecraft. Moreover, it makes it possible to establish criteria for detecting slow-moving low-convection flame. Such fires are particularly dangerous because they may not generate enough smoke and heat to activate regular smoke detectors.

Apart from fire detection in outer space, a better understanding of flame dynamics may help detect flames that propagate through panel-enclosed surfaces. This would be crucial for airplane safety, where even a small fire can lead to catastrophe.

Dr. Olami holds the Morris and Ida Wolf Career Development Chair.

###

The Weizmann Institute of Science, in Rehovot, Israel, is one of the world's foremost centers of scientific research and graduate study. Its 2,500 scientists, students, technicians, and engineers pursue basic research in the quest for knowledge and the enhancement of the human condition. New ways of fighting disease and hunger, protecting the environment, and harnessing alternative sources of energy are high priorities.


Story Source:

The above story is based on materials provided by Weizmann Institute. Note: Materials may be edited for content and length.


Cite This Page:

Weizmann Institute. "Fire On The Move." ScienceDaily. ScienceDaily, 11 September 1998. <www.sciencedaily.com/releases/1998/09/980911074053.htm>.
Weizmann Institute. (1998, September 11). Fire On The Move. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/1998/09/980911074053.htm
Weizmann Institute. "Fire On The Move." ScienceDaily. www.sciencedaily.com/releases/1998/09/980911074053.htm (accessed October 1, 2014).

Share This



More Matter & Energy News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Argentina's Tax Evaders Detected, Hunted Down by Drones

Argentina's Tax Evaders Detected, Hunted Down by Drones

AFP (Sep. 30, 2014) Argentina doesn't only have Lionel Messi the footballer, it has now also acquired "Mesi" the drone system which monitors undeclared mansions, swimming pools and soy fields to curb tax evasion in the country. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
Do Video Games Trump Brain Training For Cognitive Boosts?

Do Video Games Trump Brain Training For Cognitive Boosts?

Newsy (Sep. 29, 2014) More and more studies are showing positive benefits to playing video games, but the jury is still out on brain training programs. Video provided by Newsy
Powered by NewsLook.com
CERN Celebrates 60 Years of Science

CERN Celebrates 60 Years of Science

Reuters - Business Video Online (Sep. 29, 2014) CERN, the European Organisation for Nuclear Research, celebrates 60 years of bringing nations together through science. As Joanna Partridge reports from inside the famous science centre it's also planning to turn the Large Hadron Collider particle accelerator back on after an upgrade. Video provided by Reuters
Powered by NewsLook.com
This 'Invisibility Cloak' Is Simpler Than Most

This 'Invisibility Cloak' Is Simpler Than Most

Newsy (Sep. 28, 2014) Researchers from the University of Rochester have created a type of invisibility cloak with simple focal lenses. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins