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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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V/stol aircraft handling criteria for hovering, low-speed and transition flight - control response and power - flight stability
Effect of lateral control characteristics on hovering of jet lift VTOL aircraft
Thrust power losses during hovering for jet VTOL AIRCRAFT, due to jet induced base loss and ground effects
Jet-induced lift loss of jet VTOL configurations in hovering condition
Hovering force-test on semispan tilt-wing VTOL MODEL to determine ground effect on full-span flaps used for yaw control
Photographic performance evaluation of hovering helicopter rotor with and without blade pitch servocontrol flaps
Flight test of V/STOL height control requirement for hovering and low speed flight under visual conditions
Flight simulator determination of human balancing reflex for control of small hovering vehicles
According to a number of system studies, large capacity advanced rotorcraft with a capability of high cruise speeds (approx.350 mph) as well as vertical and/or short take-off and landing (V/STOL) flight could alleviate anticipated air transportation capacity issues by making use of non-primary runways, taxiways, and aprons. These advanced aircraft pose a number of design challenges, as well as unknown issues in the flight control and handling qualities domains. A series of piloted simulation experiments have been conducted on the NASA Ames Research Center Vertical Motion Simulator (VMS) in recent years to systematically investigate the fundamental flight control and handling qualities issues associated with the characteristics of large rotorcraft, including tiltrotors, in hover and low-speed maneuvering.
A rotor hover test was performed inside the JPL 25-foot-diameter Space Simulator. The 40-inch-diameter rotor was tested at two locations in the chamber-on the chamber centerline and 2m off-axis. The rotor was tested in both upright and inverted configurations for 500 < RPM < 2000. Fluorescent tufts were used to identify regions of recirculation. Velocities on the entrainment side of the rotor were measured. Tabulated values for the mean entrainment velocity components and the corresponding root mean square velocity fluctuations are provided. Unsteady velocity measurements provide a description of the turbulence ingested into the rotor plane and quantify the unsteady velocity field that the Mars Scout Helicopter can expect to encounter during free flight inside the Space Simulator.
The effect of turbulence models in the off-body grids on the accuracy of solutions for rotor flows in hover has been investigated. Results from the Reynolds-Averaged Navier-Stokes and Laminar Off-Body models are compared. Advection of turbulent eddy viscosity has been studied to find the mechanism leading to inaccurate solutions. A coaxial rotor result is also included.
Attitude control requirements for hovering vtol aircraft utilizing ames piloted simulator
Jet induced lift diminution on VTOL aircraft hovering in and out of ground effect
Hovering tests of extremely flexible lifting rotor to determine effects of rotor tip configuration and operating conditions on performance
Lift loss and jet decay measurements on hovering vertical takeoff aircraft models
Evaluation of six degrees of freedom motion simulator for Bell X-14A aircraft hovering characteristics
Flight evaluation of tip turbine driven fans for lateral control in hovering VTOL aircraft
VTOL display and control system for deceleration to instrument hover