Aerodynamic Rig Test Results of an Advanced Small Engine Power Turbine

Affordable power turbine technology advancements are necessary to support Army helicopter modernization requirements for mission range and lift capability. Significant improvements in engine fuel consumption, horsepower-to-weight and durability will be required within tight installation envelopes. Power turbine technologies will play an important role in meeting these engine requirements. This paper summarizes the results of the Advanced Power Turbine (APT) Program, a Technical Investment Agreement between the General Electric Company and the Applied Aviation Technology Directorate at Ft. Eustis, Virginia performed between 2001 and 2004. The APT produced a three stage power turbine design for an engine in the 3000 - plus shp class range with technologies and innovative features considered critical to all future rotorcraft. These technologies and features include low solidity, high lift airfoils and 3-Dimensional aerodynamic airfoil features such as camber, lean, and sweep. The well-integrated mechanical-aerodynamic power turbine design reduced airfoil count by 15% and significantly increased power turbine inlet temperature capability relative to current production and pre-production designs. A full-scale test article was fabricated, assembled and tested in an aerodynamic rig facility with full pressure, flow, and Reynolds Number capability. Design point tests verified a 2-3 point efficiency improvement over current designs with the potential for further airfoil count reduction and efficiency improvement.