TOPIC: A2 Fundamental Aeronautics

A2.01 Materials and Structures for Future Aircraft
A2.02 Combustion for Aerospace Vehicles
A2.03 Aero-Acoustics
A2.04 Aeroelasticity
A2.05 Aerodynamics
A2.06 Aerothermodynamics
A2.07 Aircraft Control and Dynamics
A2.08 Experimental Capabilities and Flight Research
A2.09 Aircraft Systems Analysis, Design and Optimization
A2.10 Rotorcraft

NASA is the Nation's leading government organization for civil aeronautical research. Within NASA's overall strategic plan Aeronautics has the goal to "Advance knowledge in the fundamental disciplines of aeronautics, and develop technologies for safer aircraft and higher capacity airspace systems." To address this goal NASA's Aeronautics Research Mission Directorate (ARMD) is organized into three separate Programs: Fundamental Aeronautics, Aviation Safety, and Airspace Systems.

The Fundamental Aeronautics Program is dedicated to the mastery and advancement of core aeronautics technologies across all flight regimes. NASA intends to invest broadly and deeply in these core competencies to produce knowledge, technology, and tools that are applicable across a broad range of air vehicles. The program encompasses cutting-edge, fundamental research in traditional aeronautical disciplines, as well as emerging fields with promising application to aeronautics. The overall program is long-term in scope as well as focused and integrated across disciplines. It is implemented through NASA's four research centers: the Ames Research Center, in Mountain View, California; the Dryden Flight Research Center in Edwards, California; the Glenn Research Center in Cleveland, Ohio; and the Langley Research Center in Hampton, Virginia.

To achieve these objectives NASA has defined a four-level approach to technology development: (1) conduct foundational research to further our fundamental understanding of the underlying physics and our ability model that physics, (2) leverage the foundational research to develop technologies and analytical tools focused on discipline-based solutions, (3) integrate methods and technologies to develop multi-disciplinary solutions, and (4) solve the aeronautics challenges for a broad range of air vehicles with system-level optimization, assessment and technology integration.

The Fundamental Aeronautics will provide for results yielding the following:

• Technology innovation and integrated, multidisciplinary analysis tools;
  
• Rapid evaluation of new concepts and technology;
  
• Accelerated application of new technology to a wide array of vehicles;
  
• Reduced environmental impact and increased public benefit of future aircraft: lower emissions, less noise, higher efficiency, and safer operation.
  

• Advanced materials design concepts and processing development (e.g., multifunctional materials concepts, innovative approaches to damage tolerant lightweight structural materials, lightweight materials concepts to mitigate lightning strike damage, hybrid materials approaches to multifunctionality and/or improved durability and damage tolerance, and high-temperature materials for propulsion system applications);
  
• Design methods for material and structural concepts (in particular, multifunctional concepts) including variable fidelity methods, uncertainty based design and optimization methods, multi-scale computational methods, and multi-physics modeling and simulation tools;
  
• Adaptive materials and structures concepts (e.g., environmentally responsive materials and structures, intrinsically load/strain sensing materials and structures, active and/or highly flexible structures, shape memory and self-healing materials, innovative non-parasitic in situ methods to detect damage, impact and structural dynamics);
  
• Concepts and techniques for advanced multifunctional and/or adaptive material and structures characterization and evaluation (including combinations of thermal and mechanical loading environments);
  
• Identification, development and verification of degradation and failure mechanisms/criteria, residual strength (and other critical residual properties) and life prediction methods, and damage science design and analysis methods;
  
• Advanced materials fabrication and processing methods and joining and assembly methods, for ceramics, metals and polymers and/or hybrids of these materials;
  
• Tribological surface sciences, and mechanical components including oil-free bearings and seals technologies.
  

• Oxidative fail-safe CMC, CMC structures for liners and airfoils;
  
• Advanced engine containment prediction tools;
  
• High temperature shape memory alloys;
  
• Accelerated life prediction tools;
  
• Rapid design methods for aircraft structures;
  
• Novel hot acoustic absorber technologies are also of interest to address the sound problems with supersonic flights.
  

• Probabilistic design and lifing methods for high and cryogenic temperature materials;
  
• Design database development, structural joining techniques and characterization methods for advanced materials;
  
• Impact models for high and cryogenic temperature materials;
  
• Structurally integrated multifunctional thermal protection systems;
  
• Identification, development and verification of environmental and mechanical degradation and failure mechanisms, failure criteria, other design critical properties;
  
• Physics-based life prediction methods for advanced high temperature composites coupled with damage tolerant design and analysis methods;
  
• Computational materials development tools for durable high temperature materials;
  
• Development of composite material systems and coatings for significantly improved hypersonic environmental durability for increased mission lifetime;
  
• Development of durable structural sensor technology for extreme environments;
  
• Advanced thermal control structural and material systems through techniques to improve vehicle safety and decrease weight resulting from combined thermal and structural loads;
  
• Oxidation modeling;
  
• Modeling of high temperature composite structures manufacturing.
  

• Validation data sets at appropriate conditions that can be used for physics-based model development;
  
• Detailed and reduced chemical kinetics mechanisms for practical fuels under rich and lean conditions for combustion calculations;
  
• Large Eddy Simulation submodels for reacting, multiphase flow simulations under realistic operating conditions;
  
• Turbulence-chemistry interaction models and validation data;
  
• Development of laser-based diagnostics and novel experimental techniques for measurements in reacting flows;
  
• Two-phase flow simulation models including liquid breakup and vaporization under subcritical and supercritical conditions;
  
• Combustion instability modeling and validation;
  
• Novel combustion simulation methodologies;
  
• Novel low emissions combustion concepts that enhance the state of the art in subsonic combustors;
  
• Active combustion control including high frequency actuators and sensors;
  
• Reformer technology and catalyst development for the processing of aviation fuels;
  
• Novel low emissions concepts suitable for low emissions operation at supersonic cruise conditions;
  
• Combustor and/or combustion physics and mechanisms, enhanced mixing concepts, ignition and flame holding, turbulent flame propagation, vitiated-test media and facility-contamination effects, hydrogen/hydrocarbon-air kinetic mechanisms, multi-phase combustion processes, and engine/propulsion component characterizations;
  
• Novel combustor concepts that advance/enhance the state-of-the-art in hypersonic propulsion to improve system performance, operability, reliability and reduce cost. Both analytic and/or experimental efforts are encouraged, as well as collaborative efforts that leverage technology from on-going research activities.
  

• Fundamental and applied computational fluid-dynamics techniques for aero-acoustic analysis, which can be adapted for design codes;
  
• Prediction of aero-acoustic noise sources including engine and airframe noise sources and sources which arise from significant interactions between airframe and propulsion systems;
  
• Prediction of sound propagation (including sonic booms) from the aircraft through a complex atmosphere to the ground. This should include interaction between noise sources and the airframe and its flowfield;
  
• Computational and analytical structural acoustics techniques for aircraft and advanced aerospace vehicle interior noise prediction, particularly for use early in the airframe design process;
  
• Prediction and control of high-amplitude aero-acoustic loads on advanced aerospace structures and the resulting dynamic response and fatigue;
  
• Innovative source identification techniques for engine (fan, jet, combustor, or turbine noise) and airframe (landing gear, high lift systems) noise sources, including turbulence details related to flow-induced noise sources typical of jets, separated regions, vortices, shear layers, etc.;
  
• Concepts for active and passive control of aero-acoustic noise sources for conventional and advanced aircraft configurations, including adaptive flow control technologies, smart structures for nozzles and inlets, and noise control technology and methods that are enabled by advanced aircraft configurations, including advanced integrated airframe-propulsion control methodologies;
  
• Technologies and techniques for active and passive interior noise control for aircraft and advanced aerospace vehicle structures;
  
• Development of synthesis and auditory display technologies for subjective assessments of aircraft community and interior noise, including sonic boom;
  
• Development and application of flight procedures for reducing community noise impact while maintaining or enhancing safety, capacity, and fuel efficiency.
  

• Development of design methodologies that include CFD steady and unsteady aerodynamics, flexible structures, and active control systems.
  
• Development of methods to predict aeroelastic phenomena and complex steady and unsteady aerodynamic flow phenomena, especially in the transonic speed range. Aeroelastic phenomena of interest include flutter, buffet, buzz, limit cycle oscillations, and gust response; flow phenomena of interest include viscous effects, vortex flows, separated flows, transonic nonlinearities, and unsteady shock motions.
  
• Development of efficient methods to generate mathematical models of wind-tunnel models and flight vehicles for performing vibration, aeroelastic, and aeroservoelastic studies.
  
• Development of unique control concepts that employ smart materials embedded in the structure and/or aerodynamic control surfaces for suppressing aeroelastic instabilities or for improving performance.
  
• Development of techniques that support simulations, ground testing, wind-tunnel tests, and flight experiments of aeroelastic phenomena.
  

• Structure-induced noise, flutter and dynamic response prediction, stiffness and strength tailoring, propulsion-specific structures, quasi-static aeroelasticity. Fluid-structure interaction, validation methods, data processing and interpretation methods, probabilistic modeling, rapid modeling analysis development, non-linear and time-varying methods development, unstructured grid methods, additional propulsion systems-specific methods, dampers, multistage effects, non-synchronous vibrations, coupling effects on blade vibration, probabilistic aerodynamics and aeroelastics. Stiffness and strength tailoring and actively controlled propulsion system core components (e.g. fan and turbine blades, vanes). High fidelity unsteady aeroelastic capability which utilize current and future computer capabilities effectively. Advanced turbomachinery active damping concept. Rapid, high-fidelity probabilistic aeroelastic modeling capability.
  
• Physics-based models for turbomachinery aeroelasticity related to highly separated flows, shedding, rotating stall, non-synchronous vibrations (NSV). Robust, fast-running, accelerated convergence, reduced-order CFD approaches to turbomachinery aeroelasticity for propulsion applications. Blade vibration measurement systems including closely spaced modes, blade-to-blade variations (mistuning) and system identification. Blade damping systems for metallic and composite blades, including passive and active damping methods.
  
• Aeroservoelasticity, including alternative control architectures, development and testing of control law concepts. Integrated tool set for fully coupled modeling and simulation of aeroservothermoelasticity / flight dynamic (ASTE/FD) and propulsion effects. Development of CFD-based methods (reduced-order models) aeroservoelasticity models that can be used to predict and alleviate gust loads, ride quality issues, and flutter issues. Fast and accurate aeroelastic analysis methods to predict fan/compressor flutter vibrations in the presence of the inlet and neighboring blade rows. Vortical effects and nonlinear unsteady aerodynamics influence on the aeroelastic/ASE response of supersonic configurations.
  
• Lightweight structures under aerodynamic loads, with emphasis on aeroelastic phenomena in hypersonic domain. High temperatures associated with high heating rates, resulting in additional complexities associated with varying thermal expansion and temperature dependent structural coefficients. Acquisition of data to verify analysis tools with these complexities.
  

• Turbulence models capturing the physics of separation onset at Reynolds numbers relevant to flight, where relevant to flight is dependent on a targeted vehicle class and mission profile;
  
• Boundary-layer transition models suitable for direct integration with state-of-the-art flow solvers;
  
• Active flow control concepts targeted at separation control with an emphasis on the development of novel, practical, lightweight, low-energy actuators;
  
• Wake decay models capturing the relevant physics into the near, mid, and far fields;
  
• Innovative aerodynamic concepts targeted at vehicle efficiency or control;
  
• Physics-based models for simultaneous low boom/low drag prediction and design;
  
• Aerodynamic concepts enabling simultaneous low boom and low drag objectives;
  
• Innovative methods to validate both flow models and aerodynamic concepts with an emphasis on aft-shock effects which are hindered by conventional wind tunnel model mounting approaches;
  
• Accurate aerodynamic analysis and multidisciplinary design tools for multi-body flexible structures in the atmospheres of planets and moons including the Earth, Mars, and Titan;
  
• Advanced flow control technologies to alleviate off-design performance penalties for reusable hypersonic vehicles.
  

• Computational methodologies for the analysis of radiation and its transport in the shock layer surrounding planetary entry vehicles;
  
• Advanced physics-based thermal and chemical non-equilibrium chemistry models;
  
• High-order accurate numerical methods and multi-scale models for Large Eddy Simulation of hypersonic transition and turbulence;
  
• Efficient implicit algorithms for the solution of stiff systems like those generated by high-order discretization methods;
  
• Studies of the interaction of gases in the shock layer with the ablating material making up the thermal protection system of the vehicle;
  
• Software tools for coupling radiation, non-equilibrium chemistry, Reynolds-averaged Navier-Stokes, and large eddy simulation codes to enable the design, development, and validation of mission configurations for entry into planetary atmospheres;
  
• Experiments and diagnostics to understand the characteristics of hypersonic flow fields, either in flight or in ground-based facilities;
  
• Computational and experimental technologies for the accurate prediction of combined cycle phenomena such as shock trains in isolators, inlet unstart, and thermal choke;
  
• Computational modeling to improve the accuracy of flow simulations for highly loaded turbomachinery;
  
• Innovative flow control methods, such as aspiration and bleed to reduce the losses associated with highly loaded turbomachinery;
  
• Assessment of the capabilities and deficiencies of currently available thermodynamics models and codes for the development of new physics based models;
  
• Development of active flow control devices such as Dielectric Barrier Discharge plasma actuators for application to turbomachinery flow control.
  

• New capabilities for the assessing the properties of advanced lightweight materials under relevant flight loads combining mechanical, thermal, and pressure loads;
  
• Development and applications of novel high temperature MEMS sensors based on silicon carbide technology;
  
• Advanced testing techniques to address such phenomena as icing and scaling effects in wind tunnels;
  
• Development of high temporal resolution optical diagnostics (such as Particle Imaging Velocimetry) capable of operating at frequencies up to 50 kHz;
  
• Development of advanced videogrammetric systems capable of characterizing the 3D shape of aerodynamic surfaces with high data acquisition rates and increased precision.
  

• Inflatable aero-structures;
  
• Innovative control surface-effectors;
  
• Innovative engine designs for UAVs;
  
• Noise reduction for Conventional Take-off and Landing/Short Take-off and Landing (CTOL/STOL) aircraft and engines;
  
• Aerodynamic systems optimization for planetary aircraft;
  
• Flexible system stability derivative identification;
  
• Innovative approaches to thermal protection that minimize aerodynamic performance degradation;
  
• Innovative approaches to structures, stability, control, and aerodynamics integration schemes;
  
• Innovative approaches to incorporation of UAV operations into commercial airspace.
  

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