Microchannel material cuts engine noise

ATLANTA, Oct. 2 (UPI) -- A U.S. research engineer says he's developed microchanneled material that reduces aircraft engine noise through a process called viscous shear.

Noise from commercial and military jet aircraft causes environmental problems for communities near airports, requiring airplanes to follow often complex noise-abatement procedures on takeoffs and landings.

But Jason Nadler of the Georgia Tech Research Institute has found a physics approach to resolve the problem. Nadler and colleagues said they have found honeycomb-like structures composed of many tiny tubes or channels can reduce sound more effectively than conventional methods.

"This approach dissipates acoustic waves by essentially wearing them out," said Nadler. "It's a phenomenological shift, fundamentally different from traditional techniques that absorb sound using a more frequency-dependent resonance."

Nadler has developed what could be the world's first superalloy micro honeycomb using a nickel-base superalloy. At approximately 30 percent density, the material is very light and also very strong and heat resistant. He says the material can attenuate aircraft engine noise by up to 30 percent.

In addition, Nadler said the micro-honeycomb materials could protect the aircraft in critical areas prone to impact from birds or other foreign objects by dissipating the energy of the collision.