Featured Research

from universities, journals, and other organizations

Patented 'noise sponge' quiets combustion

Date:
May 1, 2012
Source:
University of Alabama
Summary:
Breakthrough technology decreases the noise generated by combustion systems at the source by placing a sponge-like material directly in the flame.

University of Alabama engineering professor Dr. Ajay Agrawal, left, with graduate students Justin Williams, right, and Joseph Meadows, center, examine the noise reduction device, or noise sponge.
Credit: Zach Riggins, University of Alabama

A sponge-like material employed by a University of Alabama engineering professor can significantly quiet combustion, possibly making work environments safer and extending the life of equipment.

Dr. Ajay K. Agrawal, the Robert F. Barfield Endowed Chair and professor of mechanical engineering, was recently granted a patent for the breakthrough technology for noise reduction in combustion.

This technology decreases the noise generated by combustion systems at the source by placing a sponge-like material directly in the flame. This patent is based on Agrawal's work on jet engine combustion with Ultramet Corp., funded by the U.S. Navy.

The combustion process in several engines, especially those of jets, produces a deafening noise that can also be devastating to the engine. Because the noise level is so high, the sound waves produced can cause intense pulsations. These pulsations shake the engine and result in mechanical failure. The more the engine is exposed to these intense acoustic pulsations, the more likely it is to break down.

So far, noise reduction has been addressed after-the-fact, suppressing the noise outside the engine after the combustion process takes place. Agrawal's technology eliminates the noise at the source, during the combustion process.

The challenge of cutting the sound level during the combustion process is that combustion happens at extremely high temperatures and pressure. Most material cannot withstand such conditions. However, Agrawal found a porous material that can tolerate the conditions of jet engine combustion.

This porous inert material, or foam, is a composite material made of hafnium carbide and silicon carbide. It can withstand intense levels of heat and pressure. The material is placed directly into the flame and acts like a sponge for the noise.

Due to its high permeability, the foam allows gases to easily flow so combustion is not interrupted, yet is much quieter. The foam surrounds the flame, cuts the noise and eliminates the potential for engine instability.

"Experimenting with combustion can be quite noisy and unstable, shaking the whole building, but when you put the foam in place, you can talk to the person next to you. It's a night and day difference," Agrawal said.

This technology reduces noise at its source, minimizing the need for bulky and expensive modifications to exhaust equipment. It also increases the uniformity of the combustion and allows for retrofitting of existing systems, which is highly cost efficient. This technology will be useful in gas turbines, burners, furnaces, power generators and other industrial devices using combustion.

The application of the technology extends beyond jet engines. Some chemical manufacturers place loud, high-capacity torches at ground level instead of safer heights to control noise. Factories that rely on combustion also face government regulations to protect employees from noise.


Story Source:

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


Cite This Page:

University of Alabama. "Patented 'noise sponge' quiets combustion." ScienceDaily. ScienceDaily, 1 May 2012. <www.sciencedaily.com/releases/2012/05/120501182757.htm>.
University of Alabama. (2012, May 1). Patented 'noise sponge' quiets combustion. ScienceDaily. Retrieved April 25, 2014 from www.sciencedaily.com/releases/2012/05/120501182757.htm
University of Alabama. "Patented 'noise sponge' quiets combustion." ScienceDaily. www.sciencedaily.com/releases/2012/05/120501182757.htm (accessed April 25, 2014).

Share This



More Matter & Energy News

Friday, April 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Next Stop America for France's TGV?

Next Stop America for France's TGV?

Reuters - Business Video Online (Apr. 24, 2014) General Electric keeps quiet on reports it's in talks to buy French turbine and train maker Alstom. Ivor Bennett reports on what could be an embarrassing rumour for the French government, with business-friendly reforms proving a hard sell. Video provided by Reuters
Powered by NewsLook.com
Raw: Obama Plays Soccer With Japanese Robot

Raw: Obama Plays Soccer With Japanese Robot

AP (Apr. 24, 2014) President Obama briefly played soccer with a robot during his visit to Japan on Thursday. The President has been emphasizing technology along with security concerns during his visit. (April 24) Video provided by AP
Powered by NewsLook.com
Obama Encourages Japanese Student-Scientists

Obama Encourages Japanese Student-Scientists

AP (Apr. 24, 2014) President Obama spoke with student innovators in Japan and urged them to take part in increased opportunities for student exchanges with the US. (April 24) Video provided by AP
Powered by NewsLook.com
UN Joint Mission Starts Removing Landmines in Cyprus

UN Joint Mission Starts Removing Landmines in Cyprus

AFP (Apr. 23, 2014) The UN mission in Cyprus (UNFICYP) led a mine clearance demonstration on Wednesday in the UN-controlled buffer zone where demining operations are being conducted near the Cypriot village of Mammari. Duration: 01:00 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:
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