NASA SBIR 2004 Solicitation


PROPOSAL NUMBER: 04 A2.04-9226
SUBTOPIC TITLE: Airframe Systems Noise Prediction and Reduction
PROPOSAL TITLE: Real-Time Noise Prediction of V/STOL Aircraft in Maneuvering Flight

SMALL BUSINESS CONCERN (Name, E-mail, Mail Address, City/State/Zip, Phone)
Continuum Dynamics, Inc.
34 Lexington Avenue
Ewing, NJ 08618-2302

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Daniel A. Wachspress
34 Lexington Avenue
Ewing, NJ 08618-2302

This proposal outlines a plan for enhancing and integrating new breakthrough technologies to provide accurate real-time noise prediction of V/STOL aircraft in maneuvering flight within a flight simulation environment. Loading, thickness and BVI noise sources, which often dominate the noise spectrum, will be predicted from first principles by coupling Continuum Dynamics, Inc.'s unique real-time full-span free-vortex wake model with Penn State University's innovative PSU-WOPWOP maneuvering flight noise prediction method. General rotorcraft configurations will be supported (e.g., tiltrotor, coaxial, tandem, main rotor/tail rotor) as well as ducted fan and powered lift aircraft. Other noise sources (e.g., broadband, engine, and self-noise) will be modeled using the most advanced empirical methods available today. Atmospheric absorption, spherical spreading, ground reflection, attenuation and acoustic phasing will be modeled through a direct coupling with Wyle Laboratory's state-of-the-art RNM code to provide accurate ground noise assessment required for low noise flight path planning. Further enhancements could lead to onboard flight management systems able to monitor and reduce ground noise levels in flight, a capability that would both improve public acceptance of V/STOL aircraft introduced into the National Airspace System and save the lives of military aviators operating rotorcraft in hostile territory.

NASA is interested in the introduction of V/STOL aircraft into the National Airspace System to increase airport capacity but must address the impact of high noise levels on passenger and community acceptance. In this regard, the proposed effort directly responds to NASA's stated goal of developing new computational models to conduct detailed assessments of candidate concepts. The flight simulation tool will enable NASA to assess ground noise levels of potential concepts, to design low noise flight paths, and to evaluate the impact of noise control procedures on crew workload without the need for expensive flight tests.

The proposed tool will offer aircraft developers and air traffic managers a method for analyzing low noise concepts in the design phase. The real-time capability will support design optimization trade studies. Heliports, airports, operators and the FAA will be able to utilize the tool in flight path planning, particularly that involving the introduction of V/STOL aircraft into the NAS. Eventual incorporation into onboard flight management systems will allow aircraft operators to monitor ground noise levels in flight. Currently there is no commercially available tool of this kind able to directly compute V/STOL noise at this high level of fidelity.