Description: In this highly interconnected world, transportation systems must feature increased flexibility and shorter door-to-door trip times to be successful. Shorter door-to-door trip times require an increased usage of rotary wing and runway independent V/STOL technology. One of the limiting factors to the increased adoption of this technology for providing feeder service to major hubs is the limited understanding of high-volume terminal area operations. Several important issues are associated with rotary wing and runway independent V/STOL aircraft, including severe aerodynamic interactions during take-off, transition and landing. There is also the possibility that the aero-acoustic environment generated in the terminal area may cause damage to buildings, unsafe working conditions for ground personnel, or unacceptable noise levels to surrounding communities. The success of commercial V/STOL transportation is predicated on being able to establish technical feasibility, societal acceptance and economic viability. The proposed aero-acoustic tool for terminal area operations offers a simulation capability to design engineers to make informed decisions based on technical (operations and handling near a terminal), societal (acoustic footprint) and economic considerations (performance) that includes the interactional aerodynamics between the aircraft and its surroundings. The designers and operators of rotary wing and V/STOL aircrafts will use the tool to evaluate, enhance and implement more efficient and safe terminal area operation guidelines. Phase I will develop the proof-of-concept of the simulation tool and use a tilt-rotor and a candidate terminal under different wind conditions to demonstrate its usefulness. In Phase II, the tool will be extended to maneuvering rotary wing and V/STOL aircrafts. In addition, it will be integrated with a graphical user interface (GUI) for ease of use.

Benefits: The simulation module developed under this initiative will find wide usage in the NASA subsonic rotary wing and runway independent technology programs. This proposal offers a simulation tool that will lay the foundation for maneuvering aero-acoustic and interactional aerodynamic V/STOL aircraft simulations during operations near a terminal, leading to more efficient and safe terminal area operation guidelines.

The tools developed under this initiative can be used by the rotorcraft industry to help design future V/STOL and rotary wing civilian and military vehicles, and for developing operating guidelines. This utility will also be useful to the transportation industry to assist in determining safe operational limits. The designers will use the tool to evaluate, enhance, and improve V/STOL aircrafts.