Sailors aboard the aircraft carrier USS Dwight D. Eisenhower (CVN 69) cross the flight deck to prepare to launch an aircraft. Dwight D. Eisenhower is underway conducting training in the Atlantic Ocean. Credit: US Navy photo by Mass Communication Specialist 2nd Class Julia A. Casper/Released

The
deafening roar of supersonic aircraft can cause hearing damage to
Sailors and Marines on flight decks, so the Office of Naval Research
(ONR) is funding a new project to help reduce jet noise, officials
announced April 12.

   

“The
noise problem falls into two categories: noise exposure on the flight
deck and noise impact on the communities surrounding air bases,” said
Dr. Brenda Henderson, deputy manager for the Jet Noise Reduction
project, part of ONR’s Noise-Induced Hearing Loss (NIHL) program. “We’re
funding the development of tools that we’ll need to help control jet
noise in tactical aircraft.”

   

With
support from ONR’s Basic Research Challenge program—which funds basic
research in new areas not already covered by other programs— the Jet
Noise Reduction project is a long-term effort. Jointly funded with NASA,
ONR is awarding grants and contracts to eight teams—six academic
institutions and two commercial companies—to develop noise-reduction
technologies, as well as measurement and prediction tools and noise
source models to dampen the noisy jet plumes that emanate from naval
aircraft.

   

Awards
totaling more than $4 million were given to teams at Brigham Young
University, California Institute of Technology, Cascade Technologies,
Innovative Technology Applications Co., University of Illinois,
University of Mississippi, Pennsylvania State University and Virginia
Tech.

   

The
intensity of sound perceived by humans is measured in decibels. For
example, a person whispering is 20 decibels and a lawn mower is 90
decibels. Factories are required to institute a hearing protection
program once noise levels reach 85 decibels. Shipboard aviation
surpasses those limits. Jet noise from tactical aircraft can reach 150
decibels on the flight line, where Sailors and Marines prepare fighters
and other aircraft for launching.

   

The
research and tools produced by the eight teams in this project will
help to create new approaches to noise-mitigation technology aimed at
reducing levels of jet exhaust noise that, when combined with hearing
protection, will result in safer noise environments for Sailors and
Marines. In addition, the lower jet exhaust noise levels will aid in
reducing noise complaints reported in communities near military bases.

   

Source: Office of Naval Research