About the Aeroelasticity Branch
High technical excellence would be a suitable descriptor for the Aeroelasticity Branch. However, another characterization could simply be “technical variety.” The branch potentially carries the responsibility of all things aeroelastic for lifting surfaces and airframes. Aeroelasticity by its nature encompasses interactions of structures (stiffness), mass properties (inertia), and aerodynamics, with occasional further considerations for thermal and propulsion effects. The branch has a rich history of aeroelastic experimentation, analyses, and computational accomplishments. Achievements include flutter suppression and gust load and buffet alleviation developments, active flexible/aeroelastic wing development, contributing to flight flutter clearance, and launch vehicle dynamics assessments. Vehicle impacts have included contributions to the flutter clearance of many military fighter and attack aircraft, commercial transports, and tiltrotors. Aeroelastic loads and performance data have been acquired for many helicopter rotor-blade systems. Other types of vehicles assessed by the Aeroelasticity Branch include supersonic transports, hypersonic aircraft, and reentry parachutes and inflatable ballutes. The branch has influenced and enabled aeroelasticity understanding for decades running. A more recent highlight branch achievement was reaching the decision to remove the PAL ramps from the external tank of the Space Shuttle. The branch has also contributed to the development of NASA and industry aerospace leadership through work and/or mentorship in the branch. Included in this list of leaders are Irving Abel, Bill Cazier, Bob Doggett, Mike Durham, Clint Eckstrom, Dr. John Edwards, Perry Hanson, Dr. Ray Kvaternik, Anna McGowan, Cathy Mangum, Wayne Mantay, Dr. Bob Moses, Dr. Jerry Newsom, Dr. Mark Nixon, Dr. Tom Noll, Bill Reed, Rodney Ricketts, Dave Seidel, Dr. Woodrow Whitlow, and Dr. Warren Young. (from RD Newsletter FY11, Issue 7)
Aeroelasticity Branch Mission
To discover and advance fundamental knowledge of aeroelastic phenomena, to develop and apply aeroelastic prediction methods to aerospace vehicles, and to provide experimental aeroelastic expertise for wind-tunnel and flight tests.
Aeroelasticity Branch supports NASA, the US Department of Defense, and the US Aerospace Industry by:
- Conceiving and developing computational-fluid-dynamic, computational-aeroelastic, and computational-aeroservoelastic analysis tools that advance the state of the art in aeroelasticity
- Using these tools, performing aeroelastic, aeroservoelastic, and unsteady aerodynamic analyses for aerospace configurations at the appropriate level of fidelity for the problem at hand
- Conducting aeroelastic, aeroservoelastic, and unsteady aerodynamic experiments, primarily in the Langley Transonic Dynamics Tunnel and gaining valuable insights available only through testing
- Validating aeroelastic analysis tools through aeroelastic testing
- Through novel and creative application of aeroelastic knowledge, providing expert aeroelastic, aeroservoelastic, and unsteady-aerodynamic consultation for critical Agency and National urgent response projects
The Aeroelasticity Branch conducts a broad-based research and technology program to obtain a fundamental understanding of aeroelastic and unsteady-aerodynamic phenomena experienced by aerospace vehicles, especially in the transonic speed regime. The program content includes theoretical aeroelasticity, experimental aeroelasticity, and advanced aeroservoelastic concepts.
Theoretical Aeroelasticity
- Computational aeroelasticity
- ‘Classical’ linear aeroelasticity
- Unsteady computational fluid dynamics
- Reduced order modeling
- Multi-body dynamics
- Loads / vibrations / stability / performance
- Methodology development, verification, validation
- Rotorcraft computational aeroelasticity and aeroacoustics
Experimental Aeroelasticity
- Decades of experience in Langley Transonic Dynamics Tunnel
- Development of experimental databases for code validation
- Conduct of flutter, divergence, loads, and steady & unsteady pressure tests
- Buffeting research
- Development and validation of aeroelastic testing techniques
- Dedicated hover test facility
- Aeroelastic helicopter wind tunnel test article
- Aeroelastic tilt rotor wind tunnel test article
- Whirl-flutter stability
Advanced Aeroservoelastic Concepts
- Computational aeroservoelasticity
- ‘Classical’ linear aeroservoelasticity
- Aeroelastic applications of smart materials
- Methodology development, verification, validation
- Flutter suppression
- Buffet load alleviation
- Gust load alleviation
- Ride quality control
- Stability augmentation
- Active twist rotor research
- Swashplate-less rotor research
Contributions of the Aeroelasticity Branch
The aeroelasticity branch has been conducting research for over 50 years in support of US-developed aircraft and launch vehicles through the use of computational methods and experimental testing. The primary laboratories for the aeroelasticity branch are the NASA Langley Transonic Dynamics Tunnel (TDT) and the Rotorcraft Hover Test Facility. With the use of these facilities and computational methods, many aerospace problems have been addressed by the branch to include:
- Determining the cause (and prevention) of fatal Lockheed Electra crashes
- Development of stability boundaries for multiple aircraft
- Determination of safe wing-store configurations for military aircraft
- Determining the stability of Space Shuttle external tank cable trays
- Acquisition of transonic buffet and ground wind loads data for nearly every US-built launch vehicle
- Investigating rudder failures of commercial aircraft
- The conduct of many non-aeroelastic tests in which the TDT was still the tunnel of choice due to its unique capabilities
Additional information regarding significant branch contributions is provided in the following papers:
- A Historical Overview of Aeroelasticity Branch and Transonic Dynamics Tunnel Contributions to Rotorcraft Technology and Development
- Transonic Dynamics Tunnel Aeroelastic Testing in Support of Aircraft Development
- Contributions of the NASA Langley Transonic Dynamics Tunnel to Launch Vehicle and Spacecraft Development
Directions to NASA Langley
Directions to Aeroelasticity Branch (in building 648)