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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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At least 1,261 records · Page 70
All sourcesNASA NTRSDOE OSTI
NASA NTRS1988

Wind tunnel pressure study and Euler code validation of a missile configuration with 77 deg swept delta wings at supersonic speeds

A wind-tunnel pressure study was conducted on an axisymmetric missile configuration in the Unitary Plan Wind Tunnel at NASA Langley Research Center. The Mach numbers ranged from 1.70 to 2.86 and the angles of attack ranged from minus 4 degrees to plus 24 degrees. The computational accuracy for limited conditions of a space-marching Euler code was assessed.

Fulton, Patsy S.↗
NASA NTRS1989

Evaluation of leading- and trailing-edge flaps on flat and cambered delta wings at supersonic speeds

An experimental investigation has been conducted to evaluate the effectiveness of leading- and trailing-edge flaps on a flat and cambered wing at superconic speeds. Results from the experimental tests showed that highly complex and three-dimensional flow can occur over the wings with leading- and/or trailing-edge flaps deflected. An analysis of the data also showed that flap effectiveness varies significantly between a cambered and flat wing of identical planform and flap geometry. Mach number effects are similar for both flat and cambered wings for all aerodynamic parameters.

Hernandez, Gloria↗
NASA NTRS1989

Low speed wind tunnel investigation of the flow about delta wing, oscillating in pitch to very high angle of attack

Six-component airload histories were obtained for models of aspect ratio 1, 1.5, and 2. Examples are given from data obtained over a range of 'reduced frequency' parameters from 0.01 to 0.08. They include the unsteady response of the leading-edge vortices, as evidenced both by the time-dependent airloads and motion pictures of smoke released from the leading edge and illuminated by a thin sheet of laser light.

Jarrah, Mohammad-Ameen M.↗
NASA NTRS1989

Flow visualization study of delta wings in wing-rock motion

Water tunnel flow visualizations have been conducted for the wing-rock phenomenon in the cases of models having different leading-edge sweeps and roundness. Wing rock, which is noted to occur in the absence of asymmetric vortex liftoff, vortex breakdown, and static hysteresis, is seen to be initiated by flowfield asymmetries that are induced by flow disturbances and vortex interactions near the apex region; one vortex is thereby strengthened while the other is weakened, inducing a roll moment. Leading-edge roundness decreases vortex strength and reduces vortex spacing, reducing the tendency to wind rock and coupled vortex motions at higher angles-of-attack.

Ng, T. Terry↗
NASA NTRS1990

Static Wind-Tunnel and Radio-Controlled Flight Test Investigation of a Remotely Piloted Vehicle Having a Delta Wing Planform

At the request of the United States Marine Corps, an exploratory wind-tunnel and flight test investigation was conducted by the Flight Dynamics Branch at the NASA Langley Research Center to improve the stability, controllability, and general flight characteristics of the Marine Corps Exdrone RPV (Remotely Piloted Vehicle) configuration. Static wind tunnel tests were conducted in the Langley 12 foot Low Speed Wind Tunnel to identify and improve the stability and control characteristics of the vehicle. The wind tunnel test resulted in several configuration modifications which included increased elevator size, increased vertical tail size and tail moment arm, increased rudder size and aileron size, the addition of vertical wing tip fins, and the addition of leading-edge droops on the outboard wing panel to improve stall departure resistance. Flight tests of the modified configuration were conducted at the NASA Plum Tree Test Site to provide a qualitative evaluation of the flight characteristics of the modified configuration.

Yip, Long P.↗
NASA NTRS1989

Latitudinal variations in plankton delta C-13 - Implications for CO2 and productivity in past oceans

Low C-13/C-12 in present-day Antarctic plankton has been ascribed to high CO2 availability. It is reported here, however, that this high-latitude C-13 depletion develops at CO2 partial pressures that are often below that of the present atmosphere and usually below that of equatorial upwelling systems. Nevertheless, because of much lower water temperatures and hence greater CO2 solubility at high latitude, the preceding pCO2 measurements translate into Antarctic surface-water CO2 (aq) concentrations that are as much as 2.5 times higher than in equatorial waters. It is calculated that an oceanic pCO2 level greater than 800 micro-atm is a warmer low-latitude Cretaceous ocean would have been required to produce the plankton C-13 depletion preserved in Cretaceous sediments.

Rau, Greg H.↗