National Advisory Committee for Aeronautics (NACA) - 4,170 Matching Results

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Stresses in and general instability of monocoque cylinders with cutouts 8: calculation of the buckling load of cylinders with long symmetric cutout subjected to pure bending

Description: Report presenting a strain-energy theory established for the calculation of the buckling load in pure bending of reinforced monocoque cylinders which have a symmetric cutout on the compression side and buckle according to general-instability patterns. The difference between this theory and other theories is the use of the axial wave length as an additional parameter whose value was determined from a minimum condition.
Date: October 1949
Creator: Hoff, N. J.; Boley, Bruno A. & Mandel, Merven W.
Partner: UNT Libraries Government Documents Department

Summary of the theoretical lift, damping-in-roll, and center-of-pressure characteristics of various wing plan forms at supersonic speeds

Description: Report presenting information for the determination of the theoretical lift, damping-in-roll, and center-of-pressure characteristics for a group of plan forms at supersonic speeds. The information is presented in three forms: equations, figures presenting generalized curves, and figures presenting curves for representative groups of configurations. Several observations are made in regards to the effect of taper ratio, angle of sweep, and aspect ratio on the values of the derivatives.
Date: October 1949
Creator: Piland, Robert O.
Partner: UNT Libraries Government Documents Department

Theoretical spanwise lift distributions of low-aspect-ratio wings at speeds below and above the speed of sound

Description: From Summary: "The spanwise lift distributions of wings of low aspect ratio but of arbitrary plan form and angle-of-attack distribution have been analyzed by two well-established concepts: the virtual-mass concept and the Weissinger method. Both concepts have been found to yield the same simple integral expression for the spanwise lift distribution in terms of the spanwise angle-of-attack distribution. Tables and figures of lit distributions of low-aspect-ratio wings have been presented."
Date: October 1949
Creator: Diederich, Franklin W. & Zlotnick, Martin
Partner: UNT Libraries Government Documents Department

Two-Dimensional Motion of a Gas at Large Supersonic Velocities

Description: "A large number of papers have been devoted to the problem of integration of equations of two-dimensional steady nonvertical adiabatic motion of a gas. Most of these papers are based on the application of the hodograph method of S. A. Chaplygin in which the plane of the hodograph of the velocity is taken as the region of variation of the independent variables in the equations of motion; the equations become linear in this plane. The exact integration of these equations is, however, obtained in the form of infinite series containing hypergeometric functions" (p. 1).
Date: October 1949
Creator: Falkovich, S. V.
Partner: UNT Libraries Government Documents Department

Two matrix methods for calculating forcing functions from known responses

Description: Report presenting an analysis of two matrix methods for calculating responses of linear systems for given forcing functions and indicial responses in order to find a method suitable for solving the inverse problem of calculating forcing functions from known responses. The results of both methods are compared with exact solutions for both the direct and the inverse problems.
Date: October 1949
Creator: Mazelsky, Bernard & Diederich, Franklin W.
Partner: UNT Libraries Government Documents Department

An analysis of supersonic aerodynamic heating with continuous fluid injection

Description: From Introduction: "The aerodynamic heating problem assumes considerable importance at high-supersonic speeds. Sanger and Bredt (reference 1) have calculated the high-speed aerodynamic forces and equilibrium surface temperature at extremely high altitudes where the molecular mean free path is large (free-molecule-flow region) compared with a characteristic body dimension. The theoretical investigation of Lees (reference 2) on the stability of the laminar boundary layer in compressible flow indicates that the laminar boundary layer is completely stable at all Reynolds numbers at supersonic speeds for a sufficiently low ratio of surface temperature to stream temperature."
Date: September 29, 1949
Creator: Klunker, E. G. & Ivey, H. Reese
Partner: UNT Libraries Government Documents Department

Aerodynamic Characteristics of a 0.5-Scale Model of the Fairchild XSAM-N-2 Lark Missile at High Subsonic Speeds

Description: "An investigation was conducted to determine the longitudinal- and lateral-stability characteristics of a 0.5-scale model of the Fairchild Lark missile. The model was tested with 0 deg and with 22.5 deg of roll. Three horizontal wings having NACA 16-009, 16-209, and 64A-209 sections were tested. Pressures were measured on both pointed and blunt noses" (p. 1).
Date: September 28, 1949
Creator: Martin, Andrew & Hunter, Harlo A.
Partner: UNT Libraries Government Documents Department

Hovering and Low-Speed Performance and Control Characteristics of the Kaman Helicopter Rotor System as Determined on the Langley Helicopter Tower. TED No. NACA DE 205

Description: From Summary: "An investigation has been conducted with the Langley helicopter tower to obtain basic performance and control characteristics of the Raman rotor system. Blade-pitch control is obtained in this configuration by utilizing an auxiliary flap to twist the blades. Rotor thrust and power required were measured for the hovering condition and over a range of wind velocities from 0 to 30 miles per hour. The control characteristics and the transient response of the rotor to various control movements were also measured."
Date: September 27, 1949
Creator: Carpenter, Paul J. & Paulnock, Russell S.
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of horizontal tails. 5: 45 degree swept-back plan form of aspect ratio 2

Description: Report presenting the results of a wind-tunnel investigation of the low-speed aerodynamic characteristics of a 45 degree sweptback horizontal-tail model of aspect ratio 2 and a comparison of these results with results for a model of the same aspect ratio with an unswept hinge line. Results regarding the lift and hinge-moment parameters, static longitudinal stability, effect of Reynolds number, effect of standard roughness, effect of removing elevator nose seal, and visualization of the air flow are provided.
Date: September 27, 1949
Creator: Dods, Jules B., Jr.
Partner: UNT Libraries Government Documents Department

Effects of systematic changes of trailing-edge angle and leading-edge radius on the variation with Mach number of the aerodynamic characteristics of a 10-percent-chord-thick NACA airfoil section

Description: Report presenting the results of a wind-tunnel investigation of the effects of variation of trailing-edge angle and leading-edge radius on the aerodynamic characteristics of a 10-percent-chord-thick airfoil section at a range of Mach numbers.
Date: September 26, 1949
Creator: Summers, James L. & Graham, Donald J.
Partner: UNT Libraries Government Documents Department

Altitude-chamber performance of British Rolls-Royce Nene II engine 1: standard 18.75-inch-diameter jet nozzle

Description: Report presenting an altitude-chamber investigation to determine the altitude performance characteristics of the British Rolls-Royce Nene II turbojet engine with a standard 18.75-inch-diameter jet nozzle. Results regarding the simulated flight performance and generalized performance across other altitude and pressure characteristics are provided.
Date: September 23, 1949
Creator: Barson, Zelmar & Wilsted, H. D.
Partner: UNT Libraries Government Documents Department

The Static-Pressure Error of a Wing Airspeed Installation of the McDonnell XF-88 Airplane in Dives to Transonic Speeds

Description: "Measurements were made, in dives to transonic speeds, of the static-pressure position error at a distance of one chord ahead of the McDonnell XF-88 airplane. The airplane incorporates a wing which is swept back 35 deg along the 0.22 chord line and utilizes a 65-series airfoil with a 9-percent-thick section perpendicular to the 0.25-chord line. The section in the stream direction is approximately 8-percent thick. Data up to a Mach number of about 0.97 were obtained within an airplane normal-force-coefficient range from about 0.05 to about 0.68" (p. 1).
Date: September 23, 1949
Creator: Goodman, Harold R.
Partner: UNT Libraries Government Documents Department

Free-flight performance of 16-inch-diameter supersonic ram-jet units 1: four units designed for combustion-chamber-inlet Mach number of 0.12 at free-stream Mach number of 1.6 (units A-2, A-3, A-4, and A-5)

Description: Report presenting free-flight investigations conducted on four 16-inch-diameter ramjet units to determine the performance at high subsonic and supersonic velocities. Data for evaluating the performance were obtained from radio-telemetering and radar-tracking equipment. Results regarding combustion performance, diffuser total-pressure recovery, thrust coefficient, and external drag coefficient are provided.
Date: September 22, 1949
Creator: Carlton, William W. & Messing, Wesley E.
Partner: UNT Libraries Government Documents Department

Flight Investigation of the Effect of Boundary-Layer Suction on Profile-Drag Coefficient at Supercritical Mach Numbers

Description: Memorandum presenting flight tests with a fighter airplane to study the effect of boundary-layer suction aft of the shock wave on airfoil drag at supercritical Mach numbers and high Reynolds numbers. Airfoil chord force was determined from pressure-distribution measurements obtained at a range of Mach numbers at steady dives. Results of the tests showed no measurable effect of suction for the suction coefficient available.
Date: September 20, 1949
Creator: Skoog, Richard B.
Partner: UNT Libraries Government Documents Department

Investigation of Extensible Wing-Tip Ailerons on an Untapered Semispan Wing at 0 Degree and 45 Degrees Sweepback

Description: Report presenting a low-speed wind-tunnel investigation to determine the lateral control characteristics of extensible wing-tip ailerons on an untapered semispan wing with two configurations; one was unswept and had an aspect ratio of 3.13 and the other was swept back 45 degrees and had an aspect ratio of 1.59. Results regarding the plain-wing aerodynamic characteristics and lateral control characteristics are provided.
Date: September 20, 1949
Creator: Hagerman, John R. & O'Hare, William M.
Partner: UNT Libraries Government Documents Department

Analysis of measured pressures on airfoils at Mach numbers near 1

Description: Report presenting measured pressure over airfoils at Mach number 1, with subsonic velocities at the nose and supersonic velocities throughout the rear portion, are analyzed by comparison with calculations for similar cases. Results regarding the theoretical basis of approximation, comparison of Prandtl-Meyer flow with measurements, comparison of linear-velocity extrapolation with measurements, and effect of boundary layer upon airfoil pressures are provided.
Date: September 19, 1949
Creator: Habel, Louis W. & Miller, Mason F.
Partner: UNT Libraries Government Documents Department

Cyclic engine operation of cast vitallium turbine blades at an exhaust-cone gas temperature of 1440 plus or minus 20 F

Description: Report presenting an investigation conducted to determine the effects of increased gas temperatures on the performance of cast Vitallium blades in a turbojet engine. Results regarding the experimental investigation and metallurgical investigation are provided.
Date: September 19, 1949
Creator: Yaker, Charles & Garrett, Floyd B.
Partner: UNT Libraries Government Documents Department

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 pitching or rolling velocity -- are explained in detail.
Date: September 19, 1949
Creator: Gessow, Alfred & Amer, Kenneth B.
Partner: UNT Libraries Government Documents Department

Report on Investigation of Developed Turbulence

Description: "The recent experiments by Jakob and Erk, on the resistance of flowing water in smooth pipes, which are in good agreement with earlier measurements by Stenton and Pannell, have caused me to change my opinion that the empirical Blasius law (resistance proportional to the 7/4 power of the mean velocity) was applicable up to arbitrarily high Reynolds numbers. According to the new tests the exponent approaches 2 with increasing Reynolds number, where it remains an open question whether or not a specific finite limiting value of the resistance factor lambda is obtained at R = infinity. With the collapse of Blasius' law the requirements which produced the relation that the velocity in the proximity of the wall varied in proportion to the 7th root of the wall distance must also become void" (p. 1).
Date: September 19, 1949
Creator: Prandtl, L.
Partner: UNT Libraries Government Documents Department

A comparison of two submerged inlets at subsonic and transonic speeds

Description: Report presenting an investigation of the operation of two submerged-type inlets in a wind tunnel at subsonic and transonic speeds. The pressure recovery was relatively constant throughout the lower subsonic speed range. The ability of the divergent-walled inlet to operate with satisfactory pressure recovery at higher free-stream Mach numbers than was possible with the parallel-walled inlet is attributed to the difference in the boundary-layer characteristics of the two types of inlets.
Date: September 15, 1949
Creator: Mossman, Emmet A.
Partner: UNT Libraries Government Documents Department

Flow studies in the asymmetric adjustable nozzle of the Ames 6-by 6-foot supersonic wind tunnel

Description: Report presenting surveys of the flow of the asymmetric adjustable nozzle of the 6- by 6-foot supersonic wind tunnel, which were made to determine the uniformity of the air stream. Test techniques for minimizing the effects of stream irregularities and the results of force and pressure-distribution tests of a swept-wing model are presented to illustrate the effectiveness of these techniques.
Date: September 15, 1949
Creator: Frick, Charles W. & Olson, Robert N.
Partner: UNT Libraries Government Documents Department

Reynolds number effect on axial-flow compressor performance

Description: Investigation conducted in the altitude wind tunnel to study the effect of Reynolds number on the performance of an axial-flow compressor. The compressor was operated as a part of a turbojet engine over a range of pressure altitudes and compressor-inlet Reynolds numbers. Results regarding compressor efficiency, air flow, and a comparison with axial-flow compressors of different design are provided.
Date: September 15, 1949
Creator: Wallner, Lewis E. & Fleming, William A.
Partner: UNT Libraries Government Documents Department

A comparison of theoretical and experimental loading on a 63 degrees swept-back wing at supersonic speeds

Description: Report presenting the pressure distribution over a highly swept wing at supersonic speeds to provide data for a comparison of measured and predicted loadings. The wing for this investigation had 63 degrees of sweepback of the leading edge, an aspect ratio of 3.5, and a taper ratio of 0.25. Over the regions influenced by the wing tip and trailing edge, the effects of viscosity apparently are responsible for the poorer agreement between theory and experiment.
Date: September 14, 1949
Creator: Stevens, Victor I. & Boyd, John W.
Partner: UNT Libraries Government Documents Department

Analytical and Experimental Investigation of 90 Degrees Supersonic Turning Passages Suitable for Supersonic Compressors or Turbines

Description: "Four 90 degree two-dimensional turning passages designed by the method of characteristics were tested at an inlet Mach number of 1.71. The measured losses varied from 5 to 15 percent of the inlet stagnation pressure. The smallest loss was obtained for a passage in which separation on the convex surface was minimized through the introduction of a favorable pressure gradient" (p. 1).
Date: September 12, 1949
Creator: Liccini, Luke L.
Partner: UNT Libraries Government Documents Department