In the news...

October 26, 2012

NASA Dryden F/A-18 to chase ‘FaINT’ sonic booms

NASA’s F/A-18B mission support aircraft 852 is pictured flying over the high desert near the Tehachapi Mountains northwest of Mojave, Calif. The aircraft will be flying a series of low-supersonic, high-altitude flight profiles during the Farfield Investigation of No Boom Threshold, or FaINT, flight research project at NASA Dryden.

NASA’s Supersonics Project will embark on its latest effort to soften sonic booms when a NASA F/A-18 aircraft takes to the air in a project called Farfield Investigation of No Boom Threshold, or FaINT, beginning in late October.

As the latest in a continuing progression of NASA supersonics research projects aimed at reducing or mitigating the effect of sonic booms, FaINT is designed to enable engineers to better understand evanescent waves, an acoustic phenomenon that occurs at the very edges or just outside of the normal sonic boom envelope.

For an aircraft flying at a supersonic speed of about Mach 1.2 or less at an altitude above 35,000 feet, the shockwaves being produced typically do not reach the ground, so no sonic boom is heard. This is because shockwaves from an aircraft flying supersonically at higher altitudes are refracted, or bent upwards, as they enter warmer air closer to the ground, due to the fact that the speed of sound increases with air temperature.

But when sonic booms curve upward they create a series of sonic boom waves that are focused along a line. This line is called a caustic line. The side of the caustic line opposite of the sonic boom waves is called the “shadow side,” where the evanescent waves are generated. This is the area that NASA researchers will study during FaINT.

“It’s exciting to help lead a new area in sonic boom flight research,” said Larry Cliatt, principal investigator for the FaINT flight project at NASA’s Dryden Flight Research Center. “We are investigating supersonic technology and research that is relatively raw in the modern sense. When overland supersonic commercial travel is commonplace, it will be efforts like this that helped get us there.”

The planned evanescent wave flights will occur over Edwards Air Force Base, Calif., where special microphone arrays placed on the southern portion of Rogers Dry Lake will again be the NASA Dryden researcher’s sensor of choice.

For the upcoming FaINT flight project, capturing the fleeting sounds of evanescent waves coming off sonic boom shockwaves will be a challenge. Similar to the shadow the sun creates behind a building, if some light were to still leak around the edges it would not get completely dark, but it would get darker the further you move away from the edge. Certain conditions and refractionscreate a similar “shadow side” of a sonic boom where evanescent waves are generated, sounding similar to distant thunder. These waves quickly fade and disappear, as supersonic shockwaves act similar to boat wakes on water,decreasing with distance.

“The FaINT team has been working hard on the development and design of the FaINTproject for the last six months,” said Brett Pauer, FaINT deputy project manager at NASA Dryden. “NASA, along with our seven industry and university partners, are ready to collect data and expand our collective knowledge of sonic boom propagation effects near the shadow side of them,” Pauer said.
Characterizing the effects of both normal and loud sonic booms in order to provide the data necessary for engineers to design future low-boom supersonic aircraft has required an amazing amount of work and tenacity by NASA engineers from the agency’s Dryden and Langley research centers, and industry partners as well.

Related sonic boom research projects preceding FaINT date back several years. Recent efforts include the Superboom Caustic Analysis and Measurement Program (SCAMP), which produced and measured amped-up, super-loud sonic booms, and the Waveforms and Sonic boom Perception and Response (WSPR) project, which gathered data from a select group of volunteer Edwards Air ForceBase residents on their individual perceptions of sonic booms produced by aircraft in supersonic flight over Edwards.

The overarching goal of NASA’s sonic boom reduction research is to shrink the sonic boom “footprint” in order to make commercial supersonic flight over land practical.

This research is funded by NASA’s Aeronautics Research Mission Directorate at NASA Headquarters in Washington, DC.




All of this week's top headlines to your email every Friday.


 
 

 

Headlines September 15, 2014

News: Navy identifies pilot presumed dead in crash - A Navy fighter pilot presumed dead after two fighter jets crashed in the far western Pacific Ocean has been identified.   Business: Boeing eyes 737-700 solution for new JSTARS - Boeing is officially planning a variant of its 737-700 commercial jetliner as a competitor for the Air Force’s...
 
 

News Briefs September 15, 2014

Australia contributing planes for anti-IS campaign Australia is preparing to contribute 600 troops and up to 10 military aircraft to the increasingly aggressive campaign against the Islamic State extremists in Syria and Iraq, Prime Minister Tony Abbott said Sept. 14. Abbott said Australia was responding to a formal request from the United States for specific...
 
 
Courtesy graphic

Lockheed Martin conducts flight tests of aircraft laser turret for DARPA

AFRL photograph The Aero-adaptive Aero-optic Beam Control turret that Lockheed Martin is developing for the Defense Advanced Research Projects Agency and the Air Force Research Laboratory has completed initial flight testing. T...
 

 

Lockheed Martin advances live, virtual, constructive training in flight test

https://www.youtube.com/watch?feature=player_embedded&v=jvXmOW8L3mU Lockheed Martin successfully tested a new solution for integrated live, virtual and constructive training during a flight demonstration at the company’s Aeronautics facility in Fort Worth, Texas. During the flight test, a pilot flying in a live F-16 engaged in a synthetic training exercise with a pilot flying as wing...
 
 
Image courtesy of NASA/JPL-Caltech/Univ. of Arizona

NASA’s Mars Curiosity rover arrives at Martian mountain

NASA’s Mars Curiosity rover has reached the Red Planet’s Mount Sharp, a Mount-Rainier-size mountain at the center of the vast Gale Crater and the rover mission’s long-term prime destination. “Curiosity n...
 
 

Raytheon begins full rate production on TALON Laser Guided Rockets

Under a $117 million contract awarded to Raytheon, Raytheon Missile Systems has begun production of the TALON Laser Guided Rocket. In 2013, the Armed Forces General Headquarters of the United Arab Emirates awarded Tawazun a contract to procure the TALON Laser Guided Rocket. “Full rate production of the TALON LGR is a significant milestone for...
 




0 Comments


Be the first to comment!


Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>