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open access

The drag of two streamline bodies as affected by protuberances and appendages

Description: This report presents the results of wind tunnel tests of two airship models conducted to determine the drag coefficients at zero pitch, and the effect of fins and cars and of flat and streamlined protuberances located at various positions along the hull. During the investigation the stern of one model was rounded off to produce a blunter shape. The extreme range of the Reynolds number based on the over-all length of the models was from 1,300,000 to 33,000,000. At large values of the Reynolds nu… more
Date: September 26, 1932
Creator: Abbott, Ira H.
open access

Investigation of Downwash, Sidewash, and Mach Number Distribution Behind a Rectangular Wing at a Mach Number of 2.41

Description: "An investigation of the nature of the flow field behind a rectangular wing of circular arc cross section has been conducted in the Langley 9-inch supersonic tunnel. Pitot- and static-pressure surveys covering a region of flow behind the wing have been made together with detailed pitot surveys throughout the region of the wake. In addition, the flow direction has been measured by means of a weathercocking vane. Theoretical calculations have been made to obtain the variation of both downwash and… more
Date: September 14, 1950
Creator: Adamson, David & Boatright, William B.
open access

A flight evaluation of the longitudinal stability characteristics associated with the pitch-up of a swept-wing airplane in maneuvering flight at transonic speeds

Description: This report presents the results of flight measurements of longitudinal stability and control characteristics made on a swept-wing jet aircraft to determine the origin of the pitch-up encountered in maneuvering flight at transonic speeds. For this purpose measurements were made of elevator angle, tail angle of attack, and wing-fuselage pitching moments (obtained from measurements of the balancing tail loads).
Date: September 12, 1951
Creator: Anderson, Seth B. & Bray, Richard S.
open access

Study of effects of sweep on the flutter of cantilever wings

Description: An experimental and analytical investigation of the flutter of sweptback cantilever wings is reported. The experiments employed groups of wings swept back by rotating and by shearing. The angle of sweep range from 0 degree to 60 degrees and Mach numbers extended to approximately 0.85. A theoretical analysis of the air forces on an oscillating swept wing of high length-chord ratio is developed, and the approximations inherent in the assumptions are discussed. Comparison with experiment indicates… more
Date: September 9, 1948
Creator: Barmby, J. G.; Cunningham, H. J. & Garrick, I. E.
open access

A wind-tunnel test technique for measuring the dynamic rotary stability derivatives at subsonic and supersonic speeds

Description: "A method is described for measuring the dynamic stability derivatives of a model airplane in a wind tunnel. The characteristic features of this system are that single-degree-of-freedom oscillations were used to obtain combinations of rolling, yawing and pitching motions; that the oscillations were excited and controlled by velocity feedback which permitted operation under conditions unfavorable for more conventional types of oscillatory testing; and that data processing was greatly simplified … more
Date: September 20, 1954
Creator: Beam, Benjamin H.
open access

Wind-tunnel investigation of air inlet and outlet openings on a streamline body

Description: In connection with the general problem of providing air flow to an aircraft power plant located within a fuselage, an investigation was conducted in the Langley 8-foot high-speed tunnel to determine the effect on external drag and pressure distribution of air inlet openings located at the nose of a streamline body. Air outlet openings located at the tail and at the 21-percent and 63-percent stations of the body were also investigated. Boundary layer transition measurements were made and correla… more
Date: September 11, 1940
Creator: Becker, John V.
open access

Test of single-stage axial-flow fan

Description: "A single-stage axial fan was built and tested in the shop of the propeller-research tunnel of the NACA. The fan comprised a simple 24-blade rotor having a diameter of 21 inches and a solidity of 0.86 and a set of 37 contravanes having a solidity of 1.33. The rotor was driven by a 25-horsepower motor capable of rotating at a speed of 3600 r.p.m. The fan was tested for volume, pressure, and efficiency over a range of delivery pressures and volumes for a wide range of contravane and blade-angle s… more
Date: September 22, 1941
Creator: Bell, E. Barton
open access

Impingement of Cloud Droplets on a Cylinder and Procedure for Measuring Liquid-Water Content and Droplet Sizes in Supercooled Clouds by Rotating Multicylinder Method

Description: "Evaluation of the rotating multicylinder method for the measurement of droplet-size distribution, volume-median droplet size, and liquid-water content in clouds showed that small uncertainties in the basic data eliminate the distinction between different cloud droplet-size distributions and are a source of large errors in the determination of the droplet size. Calculations of the trajectories of cloud droplets in incompressible and compressible flow fields around a cylinder were performed on a… more
Date: September 5, 1952
Creator: Brun, R. J.; Lewis, W.; Perkins, P. J. & Serafini, J. S.
open access

Theoretical symmetric span loading due to flap deflection for wings of arbitrary plan form at subsonic speeds

Description: From Summary: "A simplified lifting-surface theory is applied to the problem of evaluating span loading due to flap deflection for arbitrary wing plan forms. With the resulting procedure, the effects of flap deflection on the span loading and associated aerodynamic characteristics can be easily computed for any wing which is symmetrical about the root chord and which has a straight quarter-chord line over the wing semispan. The effects of compressibility and spanwise variation of section lift-c… more
Date: September 22, 1950
Creator: DeYoung, John
open access

Some approximate equations for the standard atmosphere

Description: This report contains the derivation of a series of simple approximate equations for density ratios and for the pressure ratio in the standard atmosphere. The accuracy of the various equations is discussed and the limits of applications are given. Several of these equations are in excellent agreement with the standard values.
Date: September 19, 1930
Creator: Diehl, Walter S.
open access

Static thrust of airplane propellers

Description: Static thrust data from more than 100 airplane propeller tests are collected from various sources and combined in working charts, from which the static thrust coefficient may be readily determined. The available data cover practically all types of propellers and are in good agreement.
Date: September 1932
Creator: Diehl, Walter S.
open access

A method for simulating the atmospheric entry of long-range ballistic missiles

Description: From Summary: "It is demonstrated with the aid of similitude arguments that a model launched from a hypervelocity gun upstream through a special supersonic nozzle should experience aerodynamic heating and resulting thermal stresses like those encountered by a long-range ballistic missile entering the earth's atmosphere. This demonstration hinges on the requirements that model and missile be geometrically similar and made of the same material, and that they have the same flight speed and Reynold… more
Date: September 15, 1955
Creator: Eggers, A. J., Jr.
open access

Theoretical calculation of the power spectra of the rolling and yawing moments on a wing in random turbulence

Description: The correlation functions and power spectra of the rolling and yawing moments on an airplane wing due to the three components of continuous random turbulence are calculated. The rolling moments to the longitudinal (horizontal) and normal (vertical) components depend on the spanwise distributions of instantaneous gust intensity, which are taken into account by using the inherent properties of symmetry of isotropic turbulence. The results consist of expressions for correlation functions or spectr… more
Date: September 6, 1956
Creator: Eggleston, John M. & Diederich, Franklin W.
open access

NACA Investigation of a Jet-Propulsion System Applicable to Flight

Description: "Following a brief history of the NACA investigation of jet propulsion, a discussion is given of the general investigation and analysis leading to the construction of the jet-propulsion ground-test mock-up. The results of burning experiments and of test measurements designed to allow quantitative flight performance predictions of the system are presented and correlated with calculations. These calculations are then used to determine the performance of the system on the ground and in the air at … more
Date: September 17, 1943
Creator: Ellis, Macon C., Jr. & Brown, Clinton E.
open access

Flame Speeds and Energy Considerations for Explosions in a Spherical Bomb

Description: "Simultaneous measurements were made of the speed of flame and the rise in pressure during explosions of mixtures of carbon monoxide, normal heptane, iso-octane, and benzene in a 10-inch spherical bomb with central ignition. From these records, fundamental properties of the explosive mixtures, which are independent of the apparatus, were computed. The transformation velocity, or speed at which flame advances into and transforms the explosive mixture, increases with both the temperature and the … more
Date: September 28, 1939
Creator: Fiock, Ernest F.; Marvin, Charles F., Jr.; Caldwell, Frank R. & Roeder, Carl H.
open access

Some Effects of Argon and Helium Upon Explosions of Carbon Monoxide and Oxygen

Description: Report presents the results of an investigation conducted to study the effects of the inert gases, argon and helium, upon flame speed and expansion ratio in exploding mixtures of carbon monoxide, oxygen and water. For the particular gas mixtures investigated the results show that: (1) With the possible exception of helium in small amounts the addition of inert gas always produces decreased flame speed and expansion ratio; (2) like volumes of argon and helium have very different effects upon fla… more
Date: September 25, 1935
Creator: Fiock, Ernst F. & Roeder, Carl H.
open access

On the flow of a compressible fluid by the hodograph method 2: fundamental set of particular flow solutions of the Chaplygin differential equation

Description: From Summary: "The differential equation of Chaplygin's jet problem is utilized to give a systematic development of particular solutions of the hodograph flow equations, which extends the treatment of Chaplygin into the supersonic range and completes the set of particular solutions. The particular solutions serve to place on a reasonable basis the use of velocity correction formulas for the comparison of incompressible and compressible flows. It is shown that the geometric-mean type of velocity… more
Date: September 29, 1944
Creator: Garrick, I. E. & Kaplan, Carl
open access

On the Flow of a Compressible Fluid by the Hodograph Method. II - Fundamental Set of Particular Flow Solutions of the Chaplygin Differential Equation

Description: From Summary: "The differential equation of Chaplygin's jet problem is utilized to give a systematic development of particular solutions of the hodograph flow equations, which extends the treatment of Chaplygin into the supersonic range and completes the set of particular solutions. The particular solutions serve to place on a reasonable basis the use of velocity correction formulas for the comparison of incompressible and compressible flows. It is shown that the geometric-mean type of velocity… more
Date: September 29, 1944
Creator: Garrick, I. E. & Kaplan, Carl
open access

Coefficients of discharge of fuel-injection nozzles for compression-ignition engines

Description: "This report presents the results of an investigation to determine the coefficients of discharge of nozzles with small, round orifices of the size used with high-speed compression-ignition engines. The injection pressures and chamber back pressures employed were comparable to those existing in compression-ignition engines during injection. The construction of the nozzles was varied to determine the effect of the nozzle design on the coefficient. Tests were also made with nozzles assembled in an… more
Date: September 11, 1930
Creator: Gelalles, A. G.
open access

Interrelation of Exhaust-Gas Constituents

Description: This report presents the results of an investigation conducted to determine the interrelation of the constituents of the exhaust gases of internal-combustion engines and the effect of engine performance on these relations. Six single-cylinder, liquid-cooled tests engines and one 9-cylinder radial air-cooled engine were tested. Various types of combustion chambers were used and the engines were operated at compression ratios from 5.1 to 7.0 using spark ignition and from 13.5 to 15.6 using compre… more
Date: September 7, 1937
Creator: Gerrish, Harold C. & Voss, Fred
open access

An introduction to the physical aspects of helicopter stability

Description: In order to provide engineers interested in rotating-wing aircraft, but with no specialized training in stability theory, some understanding of the factors that influence the flying qualities of the helicopter, an explanation is made of both the static stability and the stick-fixed oscillation in hovering and forward flight in terms of fundamental physical quantities. Three significant stability factors -- static stability with angle of attack, static stability with speed, and damping due to a … more
Date: September 19, 1949
Creator: Gessow, Alfred & Amer, Kenneth B.
open access

Equations and Charts for the Rapid Estimation of Hinge-Moment and Effectiveness Parameters for Trailing-Edge Controls Having Leading and Trailing Edges Swept Ahead of the Mach Lines

Description: "Existing conical-flow solutions have been used to calculate the hinge-moments and effectiveness parameters of trailing-edge controls having leading and trailing edges swept ahead of the Mach lines and having streamwise root and tip chords. Equations and detailed charts are presented for the rapid estimation of these parameters. Also included is an approximate method by which these parameters may be corrected for airfoil-section thickness" (p. 937).
Date: September 8, 1950
Creator: Goin, Kennith L.
open access

Attainable Circulation About Airfoils in Cascade

Description: "From consideration of available information on boundary-layer behavior, a relation among profile thickness, maximum surface velocity, Reynolds number, velocity diagram, and solidity is established for a cascade of airfoils immersed in a two-dimensional incompressible fluid flow. Several cascades are computed to show the effect of various cascade design parameters on minimum required cascade solidity. Comparisons with experimentally determined blade performance show that the derived blade loadi… more
Date: September 1949
Creator: Goldstein, Arthur W. & Mager, Artur
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