National Advisory Committee for Aeronautics (NACA) - 2,226 Matching Results

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The aerodynamic design of supersonic propellers from structural considerations

Description: From Summary: "The aerodynamic design of propellers from considerations of centrifugal force is presented. By applying a constant minimum value of thickness ratio from root to tip and allowing the distribution of required area to appear in the blade plan form, propellers with good efficiency are realized at high Mach numbers by the method of this paper."
Date: December 1952
Creator: Hammack, Jerome B
Partner: UNT Libraries Government Documents Department

Aerodynamic Effects Caused by Icing of an Unswept NACA 65A004 Airfoil

Description: The effects of ice formations on the section lift, drag, and pitching-moment coefficients of an unswept NACA 65A004 airfoil section of 6-foot chord were studied.. The magnitude of the aerodynamic penalties was primarily a function of the shape and size of the ice formation near the leading edge of the airfoil. The exact size and shape of the ice formations were determined photographically and found to be complex functions of the operating and icing conditions. In general, icing of the airfoil at angles of attack less than 40 caused large increases in section drag coefficients (as much as 350 percent in 8 minutes of heavy glaze icing), reductions in section lift coefficients (up to 13 percent), and changes in the pitching-moment coefficient from diving toward climbing moments. At angles of attack greater than 40 the aerodynamic characteristics depended mainly on the ice type. The section drag coefficients generally were reduced by the addition of rime ice (by as much as 45 percent in 8 minutes of icing). In glaze icing, however, the drag increased at these angles of attack. The section lift coefficients were variably affected by rime-ice formations; however, in glaze icing, lift increases at high angles of attack amounted to as much as 9 percent for an icing time of 8 minutes. Pitching-moment-coefficient changes in icing conditions were somewhat erratic and depended on the icing condition. Rotation of the iced airfoil to angles of attack other than that at which icing occurred caused sufficiently large changes in the pitching-moment coefficient that, in flight, rapid corrections in trim might be required in order to avoid a hazardous situation.
Date: February 1958
Creator: Gray, Vernon H. & vonGlahn, Uwe H.
Partner: UNT Libraries Government Documents Department

The aerodynamic forces and moments on a 1/10-scale model of a fighter airplane in spinning attitudes as measured on a rotary balance in the Langley 20-foot free-spinning tunnel

Description: From Introduction: "This investigation provides general information on the magnitudes and directions of the aerodynamic forces and moments acting on a fighter airplane in fully developed spins. The investigation includes the determination of the effects on the aerodynamic forces and moments of varied rudder setting with and against the spin, of tail modifications, and of deflected flaps and lowered landing gear."
Date: September 1950
Creator: Stone, Ralph W , Jr; Burk, Sanger M , Jr & Bihrle, William, Jr
Partner: UNT Libraries Government Documents Department

Aerodynamic forces, moments, and stability derivatives for slender bodies of general cross section

Description: From Introduction: "The present paper employs an approach believed to be novel in slender-body theory and is concerned with developing formulas for the forces and moments as well as the stability derivatives for slender wing-body combinations."
Date: November 1954
Creator: Sacks, Alvin H
Partner: UNT Libraries Government Documents Department

Aerodynamic forces, moments, and stability derivatives for slender bodies of general cross section

Description: From Introduction: "The present paper employs an approach believed to be novel in slender-body theory and is concerned with developing formulas for the forces and moments as well as the stability derivatives for general slender wing-body combinations."
Date: November 1954
Creator: Sacks, Alvin H.
Partner: UNT Libraries Government Documents Department

Aerodynamic interference of slender wing-tail combinations

Description: From Introduction: "In the present paper, the emphasis is placed on calculating the variations of total forces and moments with angles of attack and sideslip for a number of slender plane and cruciform wing-tail combinations and for some airplane-type arrangements of a plane wing and a horizontal and vertical tail."
Date: January 1957
Creator: Sacks, Alvin H
Partner: UNT Libraries Government Documents Department

Aerodynamic investigation of a parabolic body of revolution at mach number of 1.92 and some effects of an annular supersonic jet exhausting from the base

Description: Report discussing an aerodynamic investigation of a slender pointed parabolic body of revolution was conducted at Mach number of 1.92 with and without the effects of an annular supersonic jet exhausting from the base.
Date: September 1956
Creator: Love, Eugene S
Partner: UNT Libraries Government Documents Department

Aerodynamics of a rectangular wing of infinite aspect ratio at high angles of attack and supersonic speeds

Description: From Introduction: "The present paper contains a first-order evaluation of a number of aerodynamic derivatives for a rectangular wing of infinite aspect ratio at finite angles of attack, based upon the linear perturbation theory for rotational flow."
Date: July 1955
Creator: Martin, John C & Malvestuto, Frank S , Jr
Partner: UNT Libraries Government Documents Department

Aerodynamics of slender wings and wing-body combinations having swept trailing edges

Description: From Introduction: "In the present paper, a general method is developed for solving low-aspect-ratio problems involving shed vortex sheets. Both direct and inverse problems are considered. The method is applicable for all planar problems where the velocity boundary conditions can be made homogeneous by differentiation in either the streamwise or the spanwise directions."
Date: March 1954
Creator: Mirels, Harold
Partner: UNT Libraries Government Documents Department

An air-flow-direction pickup suitable for telemetering use on pilotless aircraft

Description: From Summary: "A free-swiveling vane-type pickup for measuring air flow direction in both the angle-of-attack and angle-of-sideslip directions is described. Test results are presented which indicate that the pickup is aerodynamically stable and has an accuracy, obtained from a bench calibration, of better than 0.3^o under conditions including acceleration up to 20g in any direction, Mach numbers from 0.5 to 2.8, dynamic pressures up to at least 65 psi. Equations and curves which can be used to obtain flow direction at the center of gravity of a maneuvering model are presented."
Date: October 1956
Creator: Ikard, Wallace L.
Partner: UNT Libraries Government Documents Department

An airborne indicator for measuring vertical velocity of airplanes at wheel contact

Description: From Introduction: "The purpose of this paper is to describe one of the means developed for measuring this quantity on a given airplane type- a trailing arm with wheel. A prototype velocity indicator was tested in the Langley impact basin to determine its accuracy. A description of the operation of this type of vertical-velocity indicator, the results of the impact-basin and flight tests, and general evaluation of the indicator are presented herein."
Date: February 1, 1953
Creator: Dreher, Robert C
Partner: UNT Libraries Government Documents Department

Airfoil profiles for minimum pressure drag at supersonic velocities : application of shock-expansion theory, including consideration of hypersonic range

Description: From Summary: "A comparison of optimum profiles determined by the shock-expansion method of this report with corresponding profiles determined by the linearized-theory method of a previous report shows only small differences in shape at Mach numbers up to infinity even though the linearized theory at high supersonic Mach numbers breaks down completely insofar as the drag of the profile is concerned. Curves are presented which show that for thin airfoils the use of a trailing-edge thickness considerably greater than the theoretical optimum can result in an excessive drag penalty at moderate supersonic Mach numbers, though not at hypersonic Mach numbers."
Date: September 17, 1952
Creator: Chapman, Dean R
Partner: UNT Libraries Government Documents Department

The Ames 10- by 14-inch supersonic wind tunnel

Description: From Introduction: "The purpose of the present report is to describe the 10- by 14-inch supersonic wind tunnel and its operational characteristics over the nominal Mach number range from 2.7 to 6.3. Rather complete calibration data on characteristics of flow in the test section are presented and briefly discussed."
Date: January 1, 1954
Creator: Eggers, A J & Nothwang, George J
Partner: UNT Libraries Government Documents Department

Analogue-computer simulation of an autopilot servo system having nonlinear response characteristics

Description: From Introduction: "The servo system considered in this report is in the latter category, due mainly to the fact its amplifier tends to saturate. An investigation of the longitudinal dynamic response of the stabilized airplane was made and the results were reported in reference 1. In this investigation it was found that when restricted to linear methods of analysis the performance of the autopilot-aircraft combination could be predicted for only the small range of operation where the elements of the autopilot operated within their linear range."
Date: June 1, 1952
Creator: Jones, Arthur L & White, John S
Partner: UNT Libraries Government Documents Department

Analysis and comparison with theory of flow-field measurements near a lifting rotor in the Langley full-scale tunnel

Description: From Introduction: "The time-averaged flows are considerably simpler to deal with theoretically than are the instantaneous flows, and the results of several theoretical analyses are available (refs. 2 to 6, for example). Several previous experimental investigations (see ref. 7 for a bibliography) have provided some qualitative information on the subject by the use of smoke in flight and in wind tunnels. However, quantitative measurements (refs. 8 to 10) are extremely scarce and, in general, are inadequate either to define the nature of the flow or to check the accuracy of the theoretical calculations."
Date: April 1, 1956
Creator: Heyson, Harry H
Partner: UNT Libraries Government Documents Department

Analysis for control application of dynamic characteristics of turbojet engine with tail-pipe burning

Description: From Introduction: "The first basic problem that must be solved before control synthesis can proceed is that of determining the dynamic characteristics of the engine. Accordingly, an analysis of the dynamic behavior of the turbojet engine with tail-pipe burning was made at the NACA Lewis laboratory and is presented herein."
Date: September 1, 1950
Creator: Feder, Melvin S. & Hood, Richard
Partner: UNT Libraries Government Documents Department

Analysis of a spin and recovery from time histories of attitudes and velocities as determined for a dynamic model of a contemporary fighter airplane in the free-spinning tunnel

Description: From Introduction: "In this paper are presented descriptions of the camera setups and associated equipment, the equations and methods used in determining the model attitudes and motions from the film, and time-history curves of the variables of the spin and recovery investigated. Discussions of the nature of the spin and recovery obtained and of factors ostensibly affecting these motions are included."
Date: April 1, 1956
Creator: Scher, Stanley H
Partner: UNT Libraries Government Documents Department