Featured Research

from universities, journals, and other organizations

Tiny Fuel Pellets May Be Safer For Hazardous Places On Earth And Burn More Efficiently In Space

Date:
July 16, 2004
Source:
University Of Southern California
Summary:
Researchers from the USC Viterbi School of Engineering say solid fuel particles may be safer for hazardous environments on earth and burn more efficiently in the microgravity of space than gaseous fuels, which are more combustible and difficult to transport.

Twin flames burning gaseous and solid fuel pellets exhibit different chemical processes on earth and in the near zero-gravity environment of space.
Credit: Image courtesy of University Of Southern California

Researchers from the USC Viterbi School of Engineering say solid fuel particles may be safer for hazardous environments on earth and burn more efficiently in the microgravity of space than gaseous fuels, which are more combustible and difficult to transport.

In the Spring 2004 issue of NASA Space Research, Fokion Egolfopoulos and Charles Campbell, of the Viterbi School’s Department of Aerospace and Mechanical Engineering, report that they have made significant progress toward understanding the complex chemical processes that take place when tiny particles of solid fuels burn.

Their findings could lead to the design of safer and more efficient solid fuels for propulsion in space or for maintaining human outposts on the moon or Mars. Their research could also benefit fire-prevention practices.

“Understanding the thermal effects is a first step toward improving fuel economy in both space vehicles and those we use on Earth,” said Egolfopoulos. “It’s also a good start towards preventing spontaneous combustion in dangerous work environments, like in lumber milling, in grain elevators or in mine galleries. It ’ s a sort of walk-before-you-run kind of thing.”

Funded by NASA, the researchers made detailed studies of solid fuel combustion, including the effects of gravity on the process. They measured the burning characteristics of various solid fuel particles on earth and in microgravity, using NASA’s KC-135 aircraft — known as the “Vomit Comet” — to simulate the weightlessness of space.

“ It takes some getting used to, but after a while, you learn to conduct the experiment very precisely, ” said Mustafa Gurhan Andac, a post-doctoral research associate from the Viterbi School's Combustion and Fuels Laboratory, who ran the experiments in the nearly weightless environment aboard the NASA aircraft. “ You only have about 23 seconds in zero-g, so you have to ignite the flame before the zero-g parabola starts and be sure to finish the experiment and record the data during those precious seconds of weightlessness. ”

In their experiments, the team used two laminar, smooth-burning flames in an “opposed-jet” configuration (see photograph) to compare the consumption of solid fuel and gaseous fuel. The bottom burner slowly spews gas to carry solid fuel pellets to the flame, while the top burner issues particle-free gas to fuel the flame.

“Depending on the prevailing flow conditions, and characteristics of the particles, some particles will ignite and burn completely, whereas others behave as half-inert and burn only partially,” Egolfopoulos said. The researchers measured particle size, speed and distribution to determine the optimal conditions for efficient combustion.

“In reduced gravity, a low-speed gas was more effective for complete fuel consumption,” said Campbell. “However, when we ignited the pellets in our laboratory at USC, in earth’s gravity, a much higher gas velocity was needed to carry the pellets to the flame. Increased speed caused some of the fuel pellets to burn incompletely.”

NASA is finding additional applications for the work as the space agency looks to longer spaceflight missions and human exploration of the moon and Mars. In trips to the moon or Mars, solid fuels derived from the lunar or Martian soil, or solid carbon, extracted from the Martian atmosphere, may fuel the astronauts ’ return flights to Earth.

The researchers have created a computational model to numerically simulate their experiments and predict the combustion of solid fuel particles in a gaseous stream, based on thermal conditions and particle properties.

They will present their findings, and a few surprises, at the 30 th International Symposium on Combustion, to be held July 25-30 in Chicago, Illinois.


Story Source:

The above story is based on materials provided by University Of Southern California. Note: Materials may be edited for content and length.


Cite This Page:

University Of Southern California. "Tiny Fuel Pellets May Be Safer For Hazardous Places On Earth And Burn More Efficiently In Space." ScienceDaily. ScienceDaily, 16 July 2004. <www.sciencedaily.com/releases/2004/07/040716081153.htm>.
University Of Southern California. (2004, July 16). Tiny Fuel Pellets May Be Safer For Hazardous Places On Earth And Burn More Efficiently In Space. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2004/07/040716081153.htm
University Of Southern California. "Tiny Fuel Pellets May Be Safer For Hazardous Places On Earth And Burn More Efficiently In Space." ScienceDaily. www.sciencedaily.com/releases/2004/07/040716081153.htm (accessed July 28, 2014).

Share This




More Matter & Energy News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Carbon Trap: US Exports Global Warming

The Carbon Trap: US Exports Global Warming

AP (July 28, 2014) AP Investigation: As the Obama administration weans the country off dirty fuels, energy companies are ramping-up overseas coal exports at a heavy price. (July 28) Video provided by AP
Powered by NewsLook.com
Shipping Crates Get New 'lease' On Life

Shipping Crates Get New 'lease' On Life

Reuters - Business Video Online (July 25, 2014) Shipping containers have been piling up as America imports more than it exports. Some university students in Washington D.C. are set to get a first-hand lesson in recycling. Their housing is being built using refashioned shipping containers. Lily Jamali reports. Video provided by Reuters
Powered by NewsLook.com
Europe's Highest Train Turns 80 in French Pyrenees

Europe's Highest Train Turns 80 in French Pyrenees

AFP (July 25, 2014) Europe's highest train, the little train of Artouste in the French Pyrenees, celebrates its 80th birthday. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
TSA Administrator on Politics and Flight Bans

TSA Administrator on Politics and Flight Bans

AP (July 24, 2014) TSA administrator, John Pistole's took part in the Aspen Security Forum 2014, where he answered questions on lifting of the ban on flights into Israel's Tel Aviv airport and whether politics played a role in lifting the ban. (July 24) Video provided by AP
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:
from the past week

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