Small, Low Cost, High Performance Engines for Miniature Munitions

Based upon the successful Phase I design, fabrication and test effort, a Phase II program to replace the hot section ball bearing of a 30 lb thrust class miniature munition turbojet engine is planned. During Phase I high-speed, high temperature, transientshock, various attitude and long endurance test demonstration runs of a simulated small turbine engine rotor mounted on air foil bearings were completed. All testing was completed on a single set of MiTi compliant foil bearings for an accumulated run timein excess of four hours. Continuous and stable operation was demonstrated even at 90-g shock loads and with the rotor operating vertically. Continuous operation with bearing temperatures in excess of 500F for over 1 hour were also achieved. Under thisproposed Phase II program, a 30 lb thrust class turbojet engine will be modified to accept a MiTi foil bearing, and will be operated to full speed under a variety of conditions with a compliant foil bearing in the hot section.