(10.) IHPTET brochure, http://www.pr.afrl.af.mil/divisions/prt/ihptet/ihptet_brochure.pdf.
Morris Jr., eds., "Integrated High Performance Turbine Engine Technology (IHPTET) Program Brochure," 2002, http://www.pr.afrl.af.mil/divisions/prt/ihptet/ihptet_brochure.pdf.
Four major IHPTET technologies are being jointly pursued by the Air Force at Wright-Patterson Air Force Base in Dayton, Ohio, and the Navy at Patuxent River, Md.: swept turbine blading to reduce power loss caused by shock, brush seal technology to cut turbine air loss, silicon nitride bearings to extend the performance life of turbine bearings, and smart actuators to enhance engine control.
Swept blading grew out of IHPTET: increasing the thrust-to-weight ratio of jet engines by compressor, resulting in smaller and lighter engines.
The first swept rotor was tested in 1986, and because of its success, swept aerodynamics was incorporated into the IHPTET program.
Swept rotors have been tested in demonstrator engines for all IHPTET engine classes.
IHPTET participant Williams International of Walled Lake, Mich., along with Rolls-Royce of London, England, started incorporating swept blading in the first stage of the FJ44 engine in the late 1980s.
Mayhew and her IHPTET colleagues developed brush seals, so called because the bristles cover the circumference of the seal like a brush whose wire bristles are compliant.
Reversing the typical path of IHPTET projects, brush seals entered commercial aviation before they were used for military applications because of the less rigorous conditions of civilian aircraft.
IHPTET engineers continue to extend the performance of brush seals.
The high speed and high temperature specifications of the Phase II IHPTET goals require bearings that can operate at 600[degrees]F and at 3 million dN (a measure of bearing speed that is a product of the bore diameter in millimeters, multiplied by the shaft speed in revolutions per minute).
Dell and his colleagues in IHPTET have a $1.5 million program funded by ARPA to qualify hybrid silicon nitride/steel ball bearings for use in the number three bearing of the C-17 military transport engine.