Description: Recent advancements in open rotor engine concepts warrant continued research, however the cost of wind tunnel tests is not insignificant. Because the jet noise of an open rotor engine, or even that of a geared fan, is very low in relation to the fan noise, it is evident that fan noise reduction technology is now just as important as jet noise reduction. A low cost test system is needed that would allow for comprehensive technology screening of open rotor concepts permitting more testing to be conducted at a lower overall cost. The approach to developing such a system will be to maximize the use of current technology in the selection and development of components. The first step to achieving this goal will be a design study that will include the following activities: define test criteria, further investigate drive motor and bearing technology, perform dynamic and structural analysis, define services such as power, cooling, lubrication, health monitoring, prepare fabrication estimate.

Benefits: The test technology resulting from this study may allow for derivative test rigs to be constructed for test in other non-NASA test facilities. Examples include the GE Aviation Cell 41 acoustic test facility in Evendale, Ohio or the Boeing Corporation Low Speed Aero-acoustic Facility (LSAF) in Seattle, Washington. Additionally, a modular, transportable test apparatus may be conceived of that would allow for testing a common rig in different test sites.

A fundamental enterprise goal of NASA is to develop new and less expensive research and test technologies for the advancement of aerodynamics. The test rig resulting from this study would provide a less expensive technology screening facility capable of demonstrating new open rotor or propeller concepts. A potential site for use of this test rig may be in the NASA Glenn Research Center Aero-Acoustic Propulsion Lab (AAPL).