Title of effort: acoustic prediction methodology and test validation for an efficient low-noise hybrid wing body subsonic transport. (reference: NASA amrd NRA NNH06ZEA001N amendment 4, appendix a.2,…

Title of effort: acoustic prediction methodology and test validation for an efficient low-noise hybrid wing body subsonic transport. (reference: NASA amrd NRA NNH06ZEA001N amendment 4, appendix a.2, topic a.2.4 hybrid wing/body technologies). The new technologies for this effort are directed primarily towards meeting the reduced noise goal. While the SAX-40 based geometry being proposed offers substantially improved fuel burn, the fuel burn goal is somewhat secondary in that the focus of the changes to the geometry are to meet the noise goal. Thus, the plan is to determine the fuel burn advantages of the configuration including impacts of potential changes to reduce noise. Since LTO NOX emissions are from the engine, emissions technology development needs to be done as an engine discipline. Therefore, this effort is to enable development of prediction methods with wind tunnel test validations using a fuel-efficient hybrid wing body configuration based on the non-proprietary CMI SAX-40 geometry. The NASA long-term goal is to develop high-fidelity physics-based prediction methods. Most of the very low flyover noise potential of the hybrid wing body derives from noise shielding for which validated fundamental prediction methods are still in an early state of development. Thus, a non-proprietary 3D definition representative of a flyable efficient transport suitable for wind tunnel testing needs to be created in phase 1. A major portion of the following phase 2 proposed effort is to design and build a wind tunnel model with test configuration requirements guided by development of the predictive methods. Advancing prediction methodologies for noise shielding will initially start with empiricism to identify the needs. As investigations continue into years 2 and 3, increasing fidelity refinements will be incorporated. The wind tunnel model will be designed and wind tunnel tested for low-speed aerodynamic and noise data in phase 2 (year 2 and year 3 respectively).