National Advisory Committee for Aeronautics (NACA) - 18 Matching Results
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- Performance of B. M. W. 185-horsepower airplane engine
- Report discusses the results of testing on a B.M.W. engine in an altitude chamber where temperature and pressure can be controlled to simulate flight at various altitudes. Results for various engine speeds, altitudes, and propeller speeds are provided.
- Analytical and experimental investigation of thrust augmentation of axial- and centrifugal-compressor turbojet engines by injection of water and alcohol in combustion chambers
- Report presenting an investigation of thrust augmentation by injection of water and water-alcohol mixtures in the combustion chambers at sea-level zero-ram flight conditions on 4000-pound-thrust axial-flow and centrifugal-flow turbojet engines. Thrust augmentation, compressor characteristics, fuel flow, and turbine-outlet-temperature distributions are presented for various injection rates and water-alcohol mixtures.
- Tests in the Ames 40- by 80-foot wind tunnel of an airplane configuration with an aspect ratio 3 triangular wing and an all-movable horizontal tail: Longitudinal and lateral characteristics
- Report presenting an investigation to determine the low-speed large-scale characteristics of an aspect ratio 3 triangular-wing airplane model. The model consisted of the wing in combination with a fuselage of fitness ratio 12.5, a thin, triangular vertical tail with a constant-chord rudder, and a thin, unswept, all-movable tail.
- Effect of Fuel-Air Ratio Concentration in Combustion Zone on Combustion Performance of a 16-Inch Ram-Jet Engine
- The results of fuel-air ratio and temperature surveys made in the flame stabilizing zone of a 16-inch ram-jet combustor indicated that the distribution of combustible mixture immediately downstream of a flame holder should be mechanically controlled if a preferred mixture composition is to be maintained in that zone. A sloping-baffle combustor configuration gave combustion efficiencies of 90 percent or greater over a range of fuel-air ratios from 0.010 to 0.045.
- Experimental Results From a Test in Rough Air at High Subsonic Speeds of a Tailless Rocket Model Having Cruciform Triangular Wings, and a Note on the Calculation of Mean Square Loads of Aircraft in Continuous Rough Air
- Report presenting results of testing of a rocket model with cruciform 60 degree triangular wings in continuous rough air at transonic speeds. The wing arrangement tested appears to be useful for improving the accuracy of the results. Results regarding the characteristics of the rough-air response, variation of acceleration with Mach number, and evaluation of the cruciform arrangement are provided.
- Low-speed measurements of static stability, damping in yaw, and damping in roll of a delta, a swept, and an unswept wing for angles of attack from 0 degrees to 90 degrees
- Report presenting a low-speed investigation to determine the static and damping derivatives of a 60 degree delta wing, a 45 degree swept wing, and an unswept wing from 0 to 90 degrees angle of attack. Results regarding the static longitudinal stability characteristics, static lateral stability characteristics, damping characteristics.
- Transonic Investigation of the Effectiveness and Loading Characteristics of a Flap-Type Aileron With and Without Paddle Balances of an Unswept-Wing-Fuselage Model
- Report presenting an investigation of the effectiveness and loading characteristics of an aileron mounted on an unswept-wing-body configuration. A flap-type outboard aileron was tested with and without paddle balances at a range of Mach numbers and angles of attack. The aileron effectiveness, hinge-moment parameter, and effect of the paddle balances are presented.
- Reduction of wave drag of wing-body combinations at supersonic speeds through body distortions
- Report presenting some methods providing sizable reductions in drag for aspect ratios of current interest. The drag savings are maintained over a wide Mach number range, particularly for low-aspect-ratio wings. A significant part of the drag reduction is found to be due to the nonaxisymmetric distortion.
- An investigation of a four-blade single-rotation propeller in combination with an NACA 1-series D-type cowing at Mach numbers up to 0.83
- Report presenting an investigation of a four-blade single-rotation propeller in combination with an NACA 1-series D-type spinner-cowling combination at Mach numbers up to 0.83. Characteristics of the propeller operating in the presence of the cowling are compared with the characteristics of the propeller with the spinner.
- Flight Investigation of the Effect of a Propulsive Jet Positioned According to the Transonic Area Rule on the Drag Coefficients of a Single-Engine Delta-Wing Configuration at Mach Numbers From 0.83 to 1.36
- Report discussing testing of a 60 degree delta-wing configuration with an engine located in a pod contiguous to the underside of the fuselage to determine the effects of the flow field and drag, lift, and longitudinal stability. Jet-on drag coefficients were found to be lower than jet-off drag coefficients at transonic speeds. The transonic-area-rule concept was also found to be viable for predicting jet effects on drag for this type of configuration.
- Effect of NACA Injection Impeller and Ducted Head Baffles on Flight Cooling Performance of Double-Row Radial Engine in Four-Engine Heavy Bomber
- "The NACA has conducted a flight investigation to improve the cooling characteristics of the installation of a double-row radial engine. The tests reported herein concern the use of the NACA injection impeller and ducted head baffles in various combinations on both the port inboard and the port outboard engines. The performance of the modified installation was evaluated by comparing it with that of the standard engines" (p. 1).
- Jet-boundary corrections for reflection-plane models in rectangular wind tunnels
- A detailed method for determining the jet-boundary corrections for reflection-plane models in rectangular wind tunnels is presented. The method includes the determination of the tunnel span local distribution and the derivation of equations for the corrections to the angle of attack, the lift and drag coefficients, and the pitching-, rolling-, yawing-, and hinge-moment coefficients. The principle effects of aerodynamic induction and of the boundary-induced curvature of the streamlines have been considered. An example is included to illustrate the method. Numerical values of the more important corrections for reflection-plane models in 7 by 10-foot closed wind tunnels are presented.
- Determination of general relations for the behavior of turbulent boundary layers
- From Summary: "An analysis has been made of a considerable amount of data for turbulent boundary layers along wings and bodies of various shapes in order to determine the fundamental variables that control the development of turbulent boundary layers. It was found that the type of velocity distribution in the boundary layer could be expressed in terms of a single parameter. This parameter was chosen as the ratio of the displacement thickness to the momentum thickness of the boundary layer. The variables that control the development of the turbulent boundary layer apparently are: (1) the ratio of the nondimensional pressure gradient, expressed in terms of the local dynamic pressure outside the boundary layer and boundary-layer thickness, to the local skin-friction coefficient and (2) the shape of the boundary layer. An empirical equation has been developed in terms of these variables that, when used with the momentum equation and the skin-friction relation, makes it possible to trace the development of the turbulent boundary layer to the separation point."
- Method of analysis for compressible flow through mixed-flow centrifugal impellers of arbitrary design
- A method is presented for analysis of the compressible flow between the hub and the shroud of mixed-flow impellers of arbitrary design. Axial symmetry was assumed, but the forces in the meridional (hub to shroud) plane, which are derived from tangential pressure gradients, were taken into account. The method was applied to an experimental mixed-flow impeller. The analysis of the flow in the meridional plane of the impeller showed that the rotational forces, the blade curvature, and the hub-shroud profile can introduce severe velocity gradients along the hub and the shroud surfaces. Choked flow at the impeller inlet as determined by the analysis was verified by experimental results.
- Wind-Tunnel Investigation at Low Speed of the Yawing, Pitching, and Static Stability Characteristics of a 1/10-Scale Model of the Grumman F9F-9 Airplane, TED No. NACA AD 3109
- "An experimental investigation has been made in the Langley stability tunnel to determine the low-speed yawing, pitching, and static stability characteristics of a 1/10-scale model of the Grumman F9F-9 airplane. Tests were made to determine the effects of duct-entrance-fairing plugs on the static lateral and longitudinal stability characteristics of the complete model in the clean condition. The remaining tests were concerned with determining tail contributions as well as the effect of duct-entrance-fairing plugs, slats, flaps, and landing gear on the yawing and pitching stability derivatives" (p. 1).
- Measurements of the wing and tail loads during the acceptance tests of Bell XS-1 research airplane
- Report presenting flight measurements obtained during acceptance tests conducted by the Bell Aircraft Corporation on the XS-1 research airplane. The primary focus was on the aerodynamic loads, handling qualities, maximum lift, and buffet boundaries of the airplane.
- Study of compressor systems for a gas-generator engine
- Report presenting various methods of providing compressor-capacity and pressure-ratio control in the gas-generator type of compound engine over a range of altitudes. The analytical results indicated that the best method of control is that in which the first stage of compression is carried out in a variable-speed supercharger driven by a hydraulic slip coupling. Results regarding the constant-pressure-ratio compressor, constant-volume compressor, comparison of piston-type and rotary compressors, effect of variable-area turbine nozzle, and effect of designing for high altitudes are provided.
- Effectiveness of Thermal-Pneumatic Airfoil-Ice-Protection System
- From Summary: "Icing and drag investigations were conducted in the NACA Lewis icing research tunnel employing a combination thermal-pneumatic de-icer mounted on a 42-inch-chord NACA 0018 airfoil. The de-icer consisted of a 3-inch-wide electrically heated strip symmetrically located about the leading edge with inflatable tubes on the upper and lower airfoil surfaces aft of the heated area. The entire de-icer extended to approximately 25 percent of chord. A maximum power density of 9.25 watts per square inch was required for marginal ice protection on the airfoil leading edge at an air temperature of 00 F and an airspeed of 300 miles per hour."