WASHINGTON, D.C., November 21, 2010 -- Magnetic resonance imaging (MRI), a medical imaging technology used to image organs and soft tissues, may hold the key to improving the efficiency of jet engines, according to Lt. Colonel Michael Benson, a Ph.D. student in Mechanical Engineering at Stanford University.
In only a few hours, an MRI collects as much three-dimensional data on flow and mixing as conventional methods that take two or more years of intensive measurement. This promises to slash the time needed to develop and test new designs that improve efficiency and performance, promising energy savings.
Benson is using MRI's to improve jet engine efficiency -- work he describes today at the American Physical Society Division of Fluid Dynamics (DFD) meeting in Long Beach, CA. The technique could also provide insights into other fluid mixing problems, ranging from combustion to the flow of oil through porous rock in a well.
Benson's study is one of the first to use an MRI to gather flow data. The technique was pioneered by Stanford researchers Christopher Elkins and John Eaton who used it to study coral colonies and turbine blades. Eaton suggested that Benson, currently in the Army, use the technique to analyze the mixing of hot combustion and cooling gases in jet turbines.
Jet engines are more efficient when they run hotter. In fact, the blades just downstream of the engine's combustor run very close to their melting point. To maximize efficiency, the trailing edges of these blades are razor thin.
"If you don't actively cool them, they melt," Benson said.
Turbine engines cool blades by diverting some incoming air into a series of snake-like passages that run through each blade.
"At some point, the blades become too thin to do that, so they peel off some skin at the end of the blade and let the air run over the trailing edge," Benson said.
When that cooler air exits the blade, it mixes w
|Contact: Jason Socrates Bardi|
American Institute of Physics