Acoustic and Electro-Optic Propagation Range Site (Maryland)
The Acoustic and Electro-Optic Propagation Range Site (AEOPRS) is a pair of ranges that conduct experiments relating to the effects of various environmental conditions on acoustic and electrooptic (EO) propagation. The ranges can be instrumented to measure the atmospheric conditions and acoustic/EO signals that have propagated through the complex environment: in particular, a littoral region. The AEOPRS provides the ability to collect detailed meteorological/acoustic/EO data for the development of state-of-the-art models and the evaluation of current acoustic/EO models. The AEOPRS is also the primary site for the Mobile Acoustic Source (MOAS), a system with environmental capabilities that exist in no other system in the world. It is a pneumatic loudspeaker system that allows scientists to verify acoustic models of atmospheric effects. The system is a true exponential horn. It generates sound sufficient for testing acoustic propagation of sources.
Drives Team Facilities (Ohio)
The Drives Team conducts research on transmissions and gearing for rotorcraft and for geared fan propulsion systems on conventional aircraft. The primary goals of drives team research are to improve safety, reduce weight and noise, and increase the life and reliability of gear transmissions. This research involves advanced transmission concepts, transmission load distribution, drive system diagnostics and health monitoring, gear failure mechanisms, gear materials, gear tooth surface improvement and lubricants, gear vibration and noise, gear thermal analysis, and analytical optimization programs to develop improved methods for transmissions design.
Robotics Research Facility (Pennsylvania)
This 60 feet x 100 feet structure on the grounds of the Fort Indiantown Gap Pennsylvania National Guard (PNG) Base is a mixed-use facility comprising office space, laboratory space, a workshop, and a high-bay facility. It is adjacent to the PNG’s primary vehicle maneuver area and Combined Arms Collective Training Facility and serves as the staging point for ground and air indoor and outdoor robotics experimentation activities using the PNG ranges.
Rotorcraft Hover Test Facility (Virginia)
The Rotorcraft Hover Test Facility (RHTF) at the NASA Langley Research Center is an ARL-specific facility dedicated to the preliminary testing of helicopter rotor systems and tilt-rotor configurations. The facility acquires some publishable data, but its larger focus is to prepare model systems for entry into the Transonic Dynamics Tunnel (TDT), a wind-tunnel facility located adjacent to the RHTF.
Single Gear Tooth-Bending Test Facility (Ohio)
NASA Glenn Research Center and ARL teamed together to develop the high speed Single Gear Tooth-Bending Test Facility, which is the only facility of its kind in the world with the capability of achieving the high cycle rates required for infinite-life testing. This facility explores the stress-cycle curve at bending stress loads of approximately 150 ksi and below in support of condition-based maintenance (CBM) and other component life-extension initiatives. The helicopter community’s shift toward a CBM strategy seeks to extend the useful life of gears and bearings in order to increase the overall affordability of the aircraft. Fatigue failures, to include gear tooth-bending fatigue, take on considerable importance as the number of cycles increases. The centerpiece of the facility is the 1,000-Hz High-Cycle Fatigue Test System. The servohydraulic system is capable of maintaining high waveform fidelity at high frequency. It has a static load capacity of ±5,500 lb force and maximum displacement capability of ±1 in. At an operating frequency of 1,000 Hz, the gear tooth is experiencing the bending equivalent to a gear rotating at a speed of 60,000 rpm.
Transonic Dynamics Tunnel (Virginia)
The Transonic Dynamics Tunnel (TDT) is a continuous flow wind-tunnel facility capable of speeds up to Mach 1.2 at stagnation pressures up to one atmosphere. The TDT has a 16-feet square slotted test section that has cropped corners and a cross-sectional area of 248 square feet. Air or R-134a, a heavy gas, is used as the test medium. The TDT is particularly suited for rotorcraft aeroelastic testing, primarily because of three advantages associated with the heavy gas. First, the high density of the test medium allows model rotor components to be heavier; thereby, more easily meeting structural design requirements while maintaining dynamic scaling. Second, the low speed of sound in R-134a (approximately 550 feet/second) permits much lower rotor rotational speeds to match full-scale hover tip Mach numbers and reduces the time-scales associated with active control concepts and dynamic response. Finally, the high density environment and low kinematic viscosity of the R-134a test medium increases the Reynolds number throughout the test envelope, which permits more accurate modeling of the full scale aerodynamic environment of the rotor system.
Turbine and Structural Seals Team Facilities (Ohio)
Seals Team Facilities conceive, develop, and test advanced turbine seal concepts to increase efficiency and durability of turbine engines. Current projects include developing non contacting seals for near-infinite life. Seals Team Facilities also perform experimental and analytical research to develop advanced structural seals. This includes propulsion system and control surface seals for next-generation launch vehicles and thermal barrier seals for solid rocket motor nozzle joints.