National Advisory Committee for Aeronautics (NACA) - 376 Matching Results

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Flight investigation of control-stick vibration of the YG-1B autogiro

Description: From Summary: "As a preliminary step in an investigation of control-stick vibration in direct-control autogiros, the periodic variations in the moments transmitted through the control system of a YG-1B autogiro were recorded in flight. The results of the measurements are presented in the form of coefficients of Fourier series expressing the varying part of the lateral and the longitudinal moments acting between rotor and fuselage at the control trunnions. The most important component of the variation in stick force was found to have frequency of three times the rotor speed and an amplitude that rose from negligible values at tip-speed ratio below 0.20 to +/-5.2 pounds longitudinally and +/-3.2 pounds laterally at tip-speed ratios of 0.35. Variations in stick force at all other frequencies were small in comparison with those at three times the rotor speed."
Date: June 1940
Creator: Bailey, F. J., Jr.
Partner: UNT Libraries Government Documents Department

Italian High-Speed Airplane Engines

Description: This paper presents an account of Italian high-speed engine designs. The tests were performed on the Fiat AS6 engine, and all components of that engine are discussed from cylinders to superchargers as well as the test set-up. The results of the bench tests are given along with the performance of the engines in various races.
Date: June 1940
Creator: Bona, C. F.
Partner: UNT Libraries Government Documents Department

A Method of Measuring Piston Temperatures

Description: "A method that makes use of thermocouples has been developed to measure the temperature of engine pistons operating at high speeds. The thermocouples installed on the moving piston are connected with a potentiometer outside the engine by means of pneumatically operated plungers, which make contact with the piston thermocouples for about 10 crankshaft degrees at the bottom of the piston stroke. The equipment is operated satisfactory at engine speeds of 2,400 r.p.m. and shows promise of successful operation at higher engine speeds" (p. 1).
Date: June 1940
Creator: Pinkel, Benjamin & Mangniello, Eugene J.
Partner: UNT Libraries Government Documents Department

Tests of Lead-Bronze Bearings in the DVL Bearing-Testing Machine

Description: "The lead-bronze bearings tested in the DVL machine have proven themselves very sensitive to load changes as in comparison with bearings of light metal. In order to prevent surface injuries and consequently running interruptions, the increase of the load has to be made in small steps with sufficient run-in time between steps. The absence of lead in the running surface, impurities in the alloy (especially iron) and surface irregularities (pores) decreases the load-carrying capacity of the bearing to two or three times that of the static load" (p. 1).
Date: June 1940
Creator: Fischer, G.
Partner: UNT Libraries Government Documents Department

Air Transport by Gliders: Some Technical Observations

Description: This short analysis may be useful in determining the real tactical possibilities of "glider trains" and in adopting the course to be followed in possible studies of these questions. In this analysis most prominent are: (a) the power required for the train in level flight; (b) its speed; (c) climb; and (d) the type of airplane best suited for towing as well as design requirements for transport gliders.
Date: June 1941
Creator: Stepniewski, Wieslaw
Partner: UNT Libraries Government Documents Department

An analytical study of wing and tail loads associated with an elevator deflection

Description: From Introduction: "The present paper covers step 1 of the outlined investigation, includes methods of computing the variation of wing and tail loads, and gives numerical results of the application of the theory to the BT-9B airplane. Finally, theoretical formulas are developed and charts are given for computing the maximum increments of wing load, the down-tail load, and the up-tail load following a given elevator displacement."
Date: June 1941
Creator: Pearson, H. A. & Garvin, J. B.
Partner: UNT Libraries Government Documents Department

Cooling effects of an airplane equipped with an NACA cowling and a wing-duct cooling system

Description: Report presenting cooling tests of a Northrop A-17A attack airplane equipped with a conventional NACA cowling and then with a wing-duct cooling system. Ground cooling for the wing-duct system without cowl flap was better than for the cowling with flap, but was improved by installing a cowl flap. Satisfactory temperatures were maintained in climb and high-speed flight, but a greater quantity of cooling air was needed for the wing-duct system.
Date: June 1941
Creator: Turner, L. I., Jr.; Bierman, David & Boothy, W. B.
Partner: UNT Libraries Government Documents Department

The Effect of Methods of Testing on the Ultimate Loads Supported by Stiffened Flat Sheet Panels Under Edge Compression

Description: Note presenting testing of two series of stiffened flat sheet specimens tested under edge compression using various end conditions: round ends, flat ends, and continuous panels. The specimens consisted of aluminum-alloy flat sheet stiffened by three hat-shaped extruded aluminum-alloy stiffeners. The results indicated that the length of the specimen has an insignificant effect on the ultimate compressive load.
Date: June 1941
Creator: Holt, Marshall
Partner: UNT Libraries Government Documents Department

Effects of Some Present-Day Airplane Design Trends on Requirements for Lateral Stability

Description: Note presenting computations made to determine the effects of some airplane design trends on the fin area and the dihedral angle required for lateral stability. The specific factors studied were wing loading, moments of inertia in roll and yaw, wing chord, and tail length. The results of the computations are presented in the form of diagrams of variations of fin area with dihedral angle for neutral stability.
Date: June 1941
Creator: Bamber, Millard J.
Partner: UNT Libraries Government Documents Department

A flight investigation of the thermal properties of an exhaust heated wing de-icing system on a Lockheed 12-A airplane

Description: From Summary: "The thermal properties are presented for the exhaust heated wing de-icing system of a Lockheed 12-A airplane which has successfully prevented a wing icing in 25 hours of flying in various icing conditions. The quantities of heat supplied for de-icing of the wings under various conditions were measured and are presented. The distribution of temperatures above the ambient air temperature for the wing surface under various operating conditions are given."
Date: June 1941
Creator: Rodert, Lewis A. & Clousing, Lawrence A.
Partner: UNT Libraries Government Documents Department

General Airfoil Theory

Description: "On the assumption of infinitely small disturbances the author develops a generalized integral equation of airfoil theory which is applicable to any motion and compressible fluid. Successive specializations yield various simpler integral equations, such as Possio's, Birnbaum's, and Prandtl's integral equations, as well as new ones for the wing of infinite span with periodic downwash distribution and for the oscillating wing with high aspect ratio. Lastly, several solutions and methods for solving these integral equations are give" (p. 1).
Date: June 1941
Creator: K├╝ssner, H. G.
Partner: UNT Libraries Government Documents Department

Power-off wind-tunnel tests of the 1/8-scale model of the Brewster F2A airplane

Description: "At the request of the Bureau of Aeronautics, Navy Department, tests were made in the 7- by 10-foot wind tunnel of the 1/8-scale model of the Brewster F2A airplane. The object of the tests was to determine the power-off static lateral and longitudinal stability and control of the complete model" (p. 1).
Date: June 1941
Creator: Lowry, John G.
Partner: UNT Libraries Government Documents Department

Preliminary Stability and Control Tests in the NACA Free-Flight Wind Tunnel and Correlation With Full-Scale Flight Tests

Description: Note presenting a study of stability and control of airplanes by means of dynamic scale models in the 12-foot free-flight wind tunnel. Tests of a scale model of the F-36A airplane were used to develop the testing technique and to afford a comparison of tests of a model in the tunnel with flight tests of the corresponding airplane. Results regarding longitudinal stability and control and lateral stability and control are provided.
Date: June 1941
Creator: Shortal, Joseph A. & Osterhout, Clayton J.
Partner: UNT Libraries Government Documents Department

The Reaction Jet as a Means of Propulsion at High Speeds

Description: Report presenting a simple equation that can be used to facilitate the appraisal of the conventional jet as a means of propulsion. The equation can be used to estimate the performance of a large variety of aeropropulsive devices. The results using this equation indicate that attainable propulsive efficiencies at high speeds below sonic velocity are certain to be lower than is common at low speeds with the conventional propeller.
Date: June 1941
Creator: Williams, David T.
Partner: UNT Libraries Government Documents Department

The theoretical lateral motions of an automatically controlled airplane subjected to a yawing moment disturbance

Description: Report presenting an investigation of the lateral motion resulting from a disturbance of the type produced by asymmetric loss of thrust for a hypothetical average airplane equipped with an automatic pilot. Plots of the resultant motion and various modes that constitute the motion are presented for fixed controls and for various amounts of autopilot.
Date: June 1941
Creator: Imlay, Frederick H.
Partner: UNT Libraries Government Documents Department

Wind-Tunnel Investigation of a Plain and a Slot-Lip Aileron on a Wing With a Full-Span Flap Consisting of an Inboard Fowler and an Outboard Slotted Flap

Description: Report presenting an investigation of a slot-lip aileron and a plain aileron, singly and in combination, on an NACA 23012 wing with a full-span flap. The characteristics of these lateral-control devices were essentially the same as those of similar devices on the wing with full-span NACA slotted flaps as tested in a previous investigation.
Date: June 1941
Creator: Rogallo, F. M. & Schuldenfrei, Marvin
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of an NACA 23012 airfoil with a 30 percent chord Maxwell slate and with trailing-edge flaps

Description: Report presenting an investigation in the 7- by 10-foot wind tunnel of an NACA 23012 airfoil with a 30 percent-chord Maxwell leading-edge slat and a slotted and a split flap. The main purpose was to determine the optimum slot cap of the Maxwell slat for, and the aerodynamic section characteristics of, the airfoil with several deflections for both types of flaps. Curves of lift, drag, and pitching-moment characteristics for optimum arrangements are provided.
Date: June 1941
Creator: Lowry, John G. & McKee, John W.
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of control-surface characteristics 1: effect of gap on the aerodynamic characteristics of an NACA 0009 airfoil with a 30-percent-chord plain flap

Description: From Summary: "Tests have been made to determine the effect of a gap at the flap nose upon the aerodynamic section characteristics of an NACA 0009 airfoil with a plain flap and tab. The results are presented in the form of airfoil and flap section characteristics for several flap deflections, tab deflections, and for four sizes of gap."
Date: June 1941
Creator: Sears, Richard I.
Partner: UNT Libraries Government Documents Department

Wind-tunnel tests of several model tractor-propeller and pusher-propeller wing extension-shaft arrangements, special report

Description: From Summary: "Tests were made in the 20-foot propeller-research tunnel to investigate the possibility of obtaining increased net efficiencies of propeller-nacelle units by enclosing the engines in the wings and by using extension shafts. A wing of 5-foot chord was fitted with a propeller drive assembly providing for several axial locations of tractor propellers and pusher propellers. A three-blade 4-foot propeller and a three-blade 3 1/2-foot propeller of special design were tested in this wing with spinners and fairings ranging in diameter from 6 to 16 inches."
Date: June 1941
Creator: Harmon, Hubert N.
Partner: UNT Libraries Government Documents Department

Flutter calculations in three degrees of freedom

Description: From Summary: "The present paper is a continuation of the general study of flutter published in NACA reports nos. 496 and 685. The paper is mainly devoted to flutter in three degrees of freedom (bending, torsion, and aileron) for which a number of selected cases have been calculated and presented in graphical form. The results are analyzed and discussed with regard to the effects of structural damping, of fractional-span ailerons, and of mass-balancing. The analysis shows that more emphasis should be put on the effect of structural damping and less on mass-balancing."
Date: June 7, 1941
Creator: Theodorsen, Theodore & Garrick, I. E.
Partner: UNT Libraries Government Documents Department

Application of Balancing Tabs to Ailerons

Description: Analysis was made to determine characteristics required of a balancing-tab system for ailerons in order to reduce aileron stick forces to any desired magnitude. Series of calculations based on section data were made to determine balancing-tab systems of various chord tabs and ailerons that will give, for a particular airplane, zero rate of aileron hinge moment with aileron deflection and yet will produce same maximum rate of roll as a plain unbalanced 15-percent chord aileron of same span. Effects of rolling velocity and of forces in tab link on aileron hinge moments have been included.
Date: June 1942
Creator: Sears, Richard I.
Partner: UNT Libraries Government Documents Department

The Characteristics of Two Model Six-Blade Counterrotating Pusher Propellers of Conventional and Improved Aerodynamic Design

Description: Two airfoil plans were used for propeller blades. One is modified Clark Y section designed for structural reliability and the second an NACA 16 airfoil section designed to produce minimum aerodynamic losses. At low air speeds, the propeller designed for aerodynamic effects showed a gain of from 1.5 to 4.0 percent in propulsive efficiency over the conventional type depending on the pitch. Because of the numerous variables involved, the effect of each one on the aerodynamic characteristics of the propellers could not be isolated.
Date: June 1942
Creator: McHugh, James G. & Pepper, Edward
Partner: UNT Libraries Government Documents Department

Cooling in cruising flight with low fuel-air ratios

Description: Report presenting testing of a Pratt & Whitney R-1830-43 engine mounted in a B-24D nacelle in the full-scale wind tunnel in order to investigation the potential improvements of fuel economy. Suggestions for improving the cruising power and cruising range by operating at specified fuel-air ratios are provided.
Date: June 1942
Creator: Silverstein, Abe & Wilson, Herbert A., Jr.
Partner: UNT Libraries Government Documents Department

Effect of an aromatic mixture added to two 100-octane fuels on engine temperatures and fuel consumption

Description: Report presenting tests conducted with an air-cooled cylinder on two fuels rated at approximately 100-octane number by the C.F.R. aviation method with and without a 40-percent addition of an aromatic mixture. The aromatic mixture consisted of 50 percent toluene, 37.5 percent xylene, and 12.5 percent benzene. Results regarding engine performance and engine temperature are provided.
Date: June 1942
Creator: Krsek, Alois, Jr. & Jones, Anthony W.
Partner: UNT Libraries Government Documents Department