Featured Research

from universities, journals, and other organizations

Peering inside the 'deflagration-to-detonation transition' of explosions

Date:
November 28, 2011
Source:
American Physical Society
Summary:
Explosions of reactive gases and the associated rapid, uncontrolled release of large amounts of energy pose threats of immense destructive power to mining operations, fuel storage facilities, chemical processing plants, and many other industrial applications. To gain a better understanding of what's going on during these explosions, researchers have studied the deflagration-to-detonation (DDT) transition, which can occur in environments ranging from experimental and industrial systems on Earth to astrophysical thermonuclear supernovae explosions.

Explosions of reactive gases and the associated rapid, uncontrolled release of large amounts of energy pose threats of immense destructive power to mining operations, fuel storage facilities, chemical processing plants, and many other industrial applications.

Related Articles


To gain a better understanding of what's going on during these explosions, US Naval Research Laboratory research physicist Alexei Poludnenko, and Elaine Oran, senior scientist for reactive flow physics, teamed up with Sandia National Laboratories' Thomas Gardiner, principal member of technical staff, to study the deflagration-to-detonation (DDT) transition, which can occur in environments ranging from experimental and industrial systems on Earth to astrophysical thermonuclear supernovae explosions.

The team presented their findings at the American Physical Society's 64th Annual DFD Meeting, on Nov. 20-22, 2011, in Baltimore, Maryland.

"Explosions are most often driven by flames propagating at relatively slow subsonic velocities," explains Poludnenko. "Under certain conditions, however, this 'slow' mode of burning can transition to a completely different regime -- detonation, a.k.a. the 'deflagration-to-detonation transition.' In this case, burning is driven by very fast, strong shock waves that can travel at more than 5 times the speed of sound. The power and destructive potential of such detonation- driven explosions is vastly greater than flame-driven ones. Understanding the conditions and physical mechanisms that can cause the transition between these two explosive modes is critical for developing proper preventive and protective measures in industrial settings."

Significant research efforts have been devoted to studying the deflagration-to-detonation transition, and progress has been made in understanding its role in confined systems. Importantly, it was discovered that walls and obstacles are instrumental in detonation formation. For example, burning in a closed space naturally leads to an increase in pressure and the formation of shocks that can be further amplified through reflections with walls and obstacles -- ultimately producing a detonation.

Walls and obstacles were clearly important in these earlier studies. But scientists also wondered if unconfined flames could be inherently susceptible to the development of detonations.

"We've used detailed computer simulations of flames in hydrogen-air and methane-air mixtures in a fully unconfined environment under atmospheric conditions to study whether detonations can indeed form in such systems," Poludnenko says.

Among their findings: A subsonic flame evolving in the presence of sufficiently intense turbulence can spontaneously form a detonation both in reactive gases on Earth as well as in the interior of the white dwarf stars -- providing a missing link for the current theoretical models of Type la supernovae (which are formed by the violent explosion of a white dwarf star).

This work is supported by the Naval Research Laboratory and the Air Force Office of Scientific Research.


Story Source:

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


Cite This Page:

American Physical Society. "Peering inside the 'deflagration-to-detonation transition' of explosions." ScienceDaily. ScienceDaily, 28 November 2011. <www.sciencedaily.com/releases/2011/11/111122113216.htm>.
American Physical Society. (2011, November 28). Peering inside the 'deflagration-to-detonation transition' of explosions. ScienceDaily. Retrieved December 17, 2014 from www.sciencedaily.com/releases/2011/11/111122113216.htm
American Physical Society. "Peering inside the 'deflagration-to-detonation transition' of explosions." ScienceDaily. www.sciencedaily.com/releases/2011/11/111122113216.htm (accessed December 17, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Wednesday, December 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

How Sony Hopes To Make Any Glasses 'Smart'

How Sony Hopes To Make Any Glasses 'Smart'

Newsy (Dec. 17, 2014) Sony's glasses module attaches to the temples of various eye- and sunglasses to add a display and wireless connectivity. Video provided by Newsy
Powered by NewsLook.com
Los Angeles Police To Receive 7,000 Body Cameras

Los Angeles Police To Receive 7,000 Body Cameras

Newsy (Dec. 17, 2014) Los Angeles Mayor Eric Garcetti announced the cameras will be distributed starting Jan. 1. Video provided by Newsy
Powered by NewsLook.com
Researchers Bring Player Pianos Back to Life

Researchers Bring Player Pianos Back to Life

AP (Dec. 17, 2014) Stanford University wants to unlock the secrets of the player piano. Researchers are restoring and studying self-playing pianos and the music rolls that recorded major composers performing their own work. (Dec. 17) Video provided by AP
Powered by NewsLook.com
France's Sauternes Wine Threatened by New Train Line

France's Sauternes Wine Threatened by New Train Line

AFP (Dec. 16, 2014) Winemakers in southwestern France's Bordeaux are concerned about a proposed high speed train line that could affect the microclimate required for the region's sweet wine. Duration: 01:06 Video provided by AFP
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