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Elliptic Cones Alone and with Wings at Supersonic Speed (open access)

Elliptic Cones Alone and with Wings at Supersonic Speed

"To help fill the gap in the knowledge of aerodynamics of shapes intermediate between bodies of revolution and flat triangular wings, force and moment characteristics for elliptic cones have been experimentally determined for Mach numbers of 1.97 and 2.94. Elliptic cones having cross-sectional axis ratios from 1 through 6 and with lengths and base areas equal to circular cones of fineness ratios 3.67 and 5 have been studied for angles of bank of 0 degree and 90 degrees. Elliptic and circular cones in combination with triangular wings of aspect ratios 1 and 1.5 also have been considered" (p. 975).
Date: July 17, 1957
Creator: Jorgensen, Leland H.
System: The UNT Digital Library
Measurement of Static Pressure on Aircraft (open access)

Measurement of Static Pressure on Aircraft

"Existing data on the errors involved in the measurement of static pressure by means of static-pressure tubes and fuselage vents are presented. The errors associated with the various design features of static-pressure tubes are discussed for the condition of zero angle of attack and for the case where the tube is inclined to flow. Errors which result from variations in the configuration of static-pressure vents are also presented" (p. 645).
Date: December 17, 1956
Creator: Gracey, William
System: The UNT Digital Library
Theoretical analysis of total-pressure loss and airflow distribution for tubular turbojet combustors with constant annulus and liner cross-sectional areas (open access)

Theoretical analysis of total-pressure loss and airflow distribution for tubular turbojet combustors with constant annulus and liner cross-sectional areas

"Compressible and incompressible flow calculations were made of the combustor total-pressure-loss coefficient and liner airflow distribution for tubular turbojet combustors having constant annulus and liner cross-sectional areas along the combustor axis. Information on static and total pressure distribution and liner air-jet entrance angles along the length of the combustor was obtained as an intermediate step in the calculations. The calculations include the effects of heat release, annulus wall friction, and variation in discharge coefficients of the liner wall openings along the combustor" (p. 899).
Date: September 17, 1956
Creator: Graves, Charles C. & Grobman, Jack S.
System: The UNT Digital Library
Wind-Tunnel Investigation of a Number of Total-Pressure Tubes at High Angles of Attack -- Subsonic, Transonic, and Supersonic Speeds (open access)

Wind-Tunnel Investigation of a Number of Total-Pressure Tubes at High Angles of Attack -- Subsonic, Transonic, and Supersonic Speeds

"The effect of inclination of the airstream on the measured pressures of 54 total-pressure tubes has been determined for angles of attack up to 60 degrees and over a Mach number range from 0.26 to 1.62. The investigation was conducted in five wind tunnels at the Langley Aeronautical Laboratory" (p. 495).
Date: January 17, 1956
Creator: Gracey, William
System: The UNT Digital Library
Lift Hysteresis at Stall as an Unsteady Boundary-Layer Phenomenon (open access)

Lift Hysteresis at Stall as an Unsteady Boundary-Layer Phenomenon

"Analysis of rotating stall of compressor blade rows requires specification of a dynamic lift curve for the airfoil section at or near stall, presumably including the effect of lift hysteresis. Consideration of the Magnus lift of a rotating cylinder suggests performing an unsteady boundary-layer calculation to find the movement of the separation points of an airfoil fixed in a stream of variable incidence. The consideration of the shedding of vorticity into the wake should yield an estimate of lift increment proportional to time rate of change of angle of attack" (p. 881).
Date: August 17, 1955
Creator: Moore, Franklin K.
System: The UNT Digital Library
Effect of ground interference on the aerodynamic and flow characteristics of a 42 degree sweptback wing at Reynolds numbers up to 6.8 x 10(6) (open access)

Effect of ground interference on the aerodynamic and flow characteristics of a 42 degree sweptback wing at Reynolds numbers up to 6.8 x 10(6)

Report presents the results of an investigation of the effects of ground interference on the aerodynamic characteristics of a 42 degree sweptback wing at distances 0.68 and 0.92 of the mean aerodynamic chord from the simulated ground to the 0.25-chord point of the mean aerodynamic chord. Survey data behind the wing, both with and without the simulated ground, are presented in the form of contour charts of downwash, sidewash, and dynamic-pressure ratio at longitudinal stations of 2.0 and 2.8 mean aerodynamic chords behind the wing.
Date: December 17, 1954
Creator: Furlong, G. Chester & Bollech, Thomas V.
System: The UNT Digital Library
Formation and Combustion of Smoke in Laminar Flames (open access)

Formation and Combustion of Smoke in Laminar Flames

"The nature and formation of smoke and its combustion were investigated. Smoke, which consist of tiny mesomorphous crystals tightly packed into popcorn-ball-like particles that agglomerate to give filaments, was found to contain about 5 percent of the hydrogen originally present in the fuel. Factors affecting smoke formation were studied in both diffusion flames and premixed Bunsen flames. It is suggested that smoking tendency increases with increasing stability of the carbon skeleton of the molecule, as determined by relative bond strength" (p. 657).
Date: August 17, 1954
Creator: Schalla, Rose L.; Clark, Thomas P. & McDonald, Glen E.
System: The UNT Digital Library
Analysis of Turbulent Heat Transfer, Mass Transfer, and Friction in Smooth Tubes at High Prandtl and Schmidt Numbers (open access)

Analysis of Turbulent Heat Transfer, Mass Transfer, and Friction in Smooth Tubes at High Prandtl and Schmidt Numbers

From Introduction: "In the analysis given herein, which was made at the NACA Lewis laboratory, the expression for eddy diffusivity given in reference 1 is modified in order to account for the effect of kinematic viscosity in reducing the turbulence in the region close to the wall. The effects of variable viscosity and of length-to-diameter ratio are also investigated."
Date: February 17, 1954
Creator: Deissler, Robert G.
System: The UNT Digital Library
The dynamic-response characteristics of a 35 degree swept-wing airplane as determined from flight measurements (open access)

The dynamic-response characteristics of a 35 degree swept-wing airplane as determined from flight measurements

From Summary: "The longitudinal and lateral-directional dynamic-response characteristics of a 35 degree swept-wing fighter-type airplane determined from flight measurements are presented and compared with predictions based on theoretical studies and wind-tunnel data. Flights were made at an altitude of 35,000 feet covering the Mach number range of 0.50 to 1.04. A limited amount of lateral-directional data were also obtained at 10,000 feet. The flight consisted essentially of recording transient responses to pilot-applied pulsed motions of each of the three primary control surfaces. These transient data were converted into frequency-response form by means of the Fourier transformation and compared with predicted responses calculated from the basic equations. Experimentally determined transfer functions were used for the evaluation of the stability derivatives that have the greatest effect on the dynamic response of the airplane. The values of these derivatives, in most cases, agreed favorably with predictions over the Mach number range of the test."
Date: September 17, 1952
Creator: Triplett, William C.; Brown, Stuart C. & Smith, G. Allan
System: The UNT Digital Library
A correlation by means of transonic similarity rules of experimentally determined characteristics of a series of symmetrical and cambered wings of rectangular plan form (open access)

A correlation by means of transonic similarity rules of experimentally determined characteristics of a series of symmetrical and cambered wings of rectangular plan form

Transonic similarity rules are applied to the correlation of experimental data for a series of related rectangular wings of varying aspect ratio, thickness, and camber. The data correlation is presented in two parts: the first part presents the correlation for a series of 22 wings having symmetrical NACA 63a-series sections; the second part is concerned with a study of one type of camber by correlation of the data for a series of 18 cambered wings having NACA 63a2xx and 63a4xx sections.
Date: December 17, 1951
Creator: McDevitt, John B.
System: The UNT Digital Library
An investigation of four wings of square plan form at a Mach number of 6.9 in the Langley 11-inch hypersonic tunnel (open access)

An investigation of four wings of square plan form at a Mach number of 6.9 in the Langley 11-inch hypersonic tunnel

The results of pressure-distribution and force tests of four wings at a Mach number of about 6.9 and a Reynolds number of 0.98 x 10(6) in the Langley 11-inch hypersonic tunnel are presented. The wings had a square plan form, a 5-percent-chord maximum thickness, and diamond, half-diamond, wedge, and half-circular sections.
Date: April 17, 1951
Creator: McLellan, Charles H.; Bertram, Mitchel H. & Moore, John A.
System: The UNT Digital Library
Spectra and diffusion in a round turbulent jet (open access)

Spectra and diffusion in a round turbulent jet

"In a round turbulent jet at room temperature, measurement of the shear correlation coefficient as a function of frequency (through band-pass filters) has given a rather direct verification of Kolmogoroff's local-isotropy hypothesis. One-dimensional power spectra of velocity and temperature fluctuations, measured in unheated and heated jets, respectively, have been contrasted. Under the same conditions, the two corresponding transverse correlation functions have been measured and compared" (p. 1).
Date: August 17, 1949
Creator: Corrsin, Stanley & Uberoi, Mahinder S.
System: The UNT Digital Library
Use of source distributions for evaluating theoretical aerodynamics of thin finite wings at supersonic speeds (open access)

Use of source distributions for evaluating theoretical aerodynamics of thin finite wings at supersonic speeds

From Summary: "A series of publications on the source-distribution methods for evaluating the aerodynamics of thin wings at supersonic speeds is summarized, extended, and unified. Included in the first part are the deviations of: (a) the linearized partial-differential equation for unsteady flow at a substantially constant Mach number. b) The source-distribution solution for the perturbation-velocity potential that satisfies the boundary conditions of tangential flow at the surface and in the plane of the wing; and (c) the integral equation for determining the strength and the location of sources to describe the interaction effects (as represented by upwash) of the bottom and top wing surfaces through the region between the finite wing boundary and the foremost Mach wave. The second part deals with steady-state thin-wing problems. The third part of the report approximates the integral equation for unsteady upwash and includes a solution of approximate equation. Expressions are then derived to evaluate the load distributions for time-dependent finite-wing motions."
Date: June 17, 1949
Creator: Evvard, John C.
System: The UNT Digital Library
Comparison of Theoretical and Experimental Heat-Transfer Characteristics of Bodies of Revolution at Supersonic Speeds (open access)

Comparison of Theoretical and Experimental Heat-Transfer Characteristics of Bodies of Revolution at Supersonic Speeds

"An investigation of the three important factors that determine convective heat-transfer characteristics at supersonic speeds, location boundary-layer transition, recovery factor, and heat-transfer parameter has been performed at Mach numbers from 1.49 to 1.18. The bodies of revolution that were tested had, in most cases, laminar boundary layers, and the test results have been compared with available theory. Boundary-layer transition was found to be affected by heat transfer" (p. 1301).
Date: December 17, 1948
Creator: Scherrer, Richard
System: The UNT Digital Library
Hydrodynamic impact of a system with a single elastic mode I : theory and generalized solution with an application to an elastic airframe (open access)

Hydrodynamic impact of a system with a single elastic mode I : theory and generalized solution with an application to an elastic airframe

Solutions of impact of a rigid prismatic float connected by a massless spring to a rigid upper mass are presented. The solutions are based on hydrodynamic theory which has been experimentally confirmed for a rigid structure. Equations are given for defining the spring constant and the ratio of the sprung mass to the lower mass so that the two-mass system provides representation of the fundamental mode of an airplane wing. The forces calculated are more accurate than the forces which would be predicted for a rigid airframe since the effect of the fundamental mode on the hydrodynamic force is taken into account. In a comparison of the theoretical data with data for a severe flight-test landing impact, the effect of the fundamental mode on the hydrodynamic force is considered and response data are compared with experimental data.
Date: March 17, 1947
Creator: Mayo, Wilbur L.
System: The UNT Digital Library
Standard nomenclature for airspeeds with tables and charts for use in calculation of airspeed (open access)

Standard nomenclature for airspeeds with tables and charts for use in calculation of airspeed

Symbols and definition of various airspeed terms that have been adopted as standard by the NACA subcommittee on aircraft structural design are presented. The equations, charts, and tables required in the evaluation of true airspeed, calibrated airspeed, equivalent airspeed, impact and dynamic pressures, and Mach and Reynolds numbers have been compiled. Tables of the standard atmosphere to an altitude of 65,000 feet and a tentative extension to an altitude of 100,000 feet are given along with the basic equations and constants on which both the standard atmosphere and the tentative extension are based.
Date: July 17, 1946
Creator: Aiken, William S., Jr.
System: The UNT Digital Library
NACA Investigation of a Jet-Propulsion System Applicable to Flight (open access)

NACA Investigation of a Jet-Propulsion System Applicable to Flight

"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 various speeds and altitudes under various burning conditions. The application of the system to an experimental airplane is described and some performance predictions for this airplane are made" (p. 1).
Date: September 17, 1943
Creator: Ellis, Macon C., Jr. & Brown, Clinton E.
System: The UNT Digital Library
Wind-Tunnel Investigation of an NACA 23012 Airfoil With 30 Percent-Chord Venetian-Blind Flaps (open access)

Wind-Tunnel Investigation of an NACA 23012 Airfoil With 30 Percent-Chord Venetian-Blind Flaps

Report presents the results of an investigation made in the NACA 7 by 10-foot wind tunnel of a NACA 23012 airfoil with 30-percent-chord venetian-blind flaps having one, two, three, and four slats of Clark y section. The three-slat arrangements was aerodynamically the best of those tested but showed practically no improvement over the comparable arrangement used in the preliminary tests published in NACA Technical Report No. 689. The multiple-slat flaps gave slightly higher lift coefficients than the one-slat (Fowler) flap but gave considerably greater pitching-moment coefficients.
Date: September 17, 1941
Creator: Rogallo, F. M. & Spano, Bartholomew S.
System: The UNT Digital Library
A simplified theoretical method of determining the characteristics of a lifting rotor in forward flight (open access)

A simplified theoretical method of determining the characteristics of a lifting rotor in forward flight

Theoretical derived expressions for the flapping, the thrust, the torque, and the profile drag-lift ratio of nonfeathering rotor with hinged, rectangular, linearly twisted blades are given as simple functions of the inflow velocity and the blade pitch. Representative values of the coefficients of each of the terms in these expressions are tabulated for a series of specified values of the tip-speed ratio. Analysis indicates that the tabulated values can be used to calculate, with reasonable accuracy, the characteristics of any rotor of conventional design.
Date: March 17, 1941
Creator: Bailey, F. J., Jr.
System: The UNT Digital Library
The effect of nacelle-propeller diameter ratio on body interference and on propeller and cooling characteristics (open access)

The effect of nacelle-propeller diameter ratio on body interference and on propeller and cooling characteristics

Report presents the results of an investigation conducted in the NACA 20-foot tunnel to determine the slipstream drag, the body interference, and the cooling characteristics of nacelle-propeller diameter. Four combinations of geometrically similar propellers and nacelles, mounted on standard wing supports, were tested with values of the ratio of nacelle diameter to propeller diameter of 0.25, 0.33, and 0.44.
Date: April 17, 1939
Creator: McHugh, James G. & Derring, Eldridge H.
System: The UNT Digital Library
Pressure distribution over an NACA 23012 airfoil with a slotted and a plain flap (open access)

Pressure distribution over an NACA 23012 airfoil with a slotted and a plain flap

Report presents the results of pressure-distribution of an NACA 23012 airfoil equipped with a slotted flap and with a plain flap conducted in the 7 by 10-foot wind tunnel. A test installation was used in which the 7-foot-span airfoil was mounted vertically between the upper and lower sides of the closed test section so that two-dimensional flow was approximated. The pressures were measured on the upper and lower surfaces at one chord section both on the main airfoil and on the flaps for several different flap deflections and at several angles of attack. The data are presented in the form of pressure-distribution diagrams and as graphs of calculated section coefficients for the airfoil-and-flap combinations and also for the flaps alone. The results are useful for application to rib and flap structural design; in addition, the plain-flap data furnish considerable information applicable to the structural design of plain ailerons.
Date: March 17, 1938
Creator: Wenzinger, Carl J. & Delano, James B.
System: The UNT Digital Library
The experimental and calculated characteristics of 22 tapered wings (open access)

The experimental and calculated characteristics of 22 tapered wings

From Summary: "The experimental and calculated aerodynamic characteristics of 22 tapered wings are compared, using tests made in the variable-density wind tunnel. The wings had aspect ratios from 6 to 12 and taper ratios from 1:6:1 and 5:1. The compared characteristics are the pitching moment, the aerodynamic-center position, the lift-curve slope, the maximum lift coefficient, and the curves of drag. The method of obtaining the calculated values is based on the use of wing theory and experimentally determined airfoil section data. In general, the experimental and calculated characteristics are in sufficiently good agreement that the method may be applied to many problems of airplane design."
Date: November 17, 1937
Creator: Anderson, Raymond F.
System: The UNT Digital Library
An Analysis of Lateral Stability in Power-Off Flight With Charts for Use in Design (open access)

An Analysis of Lateral Stability in Power-Off Flight With Charts for Use in Design

"The aerodynamic and mass factors governing lateral stability are discussed and formulas are given for their estimation. Relatively simple relationships between the governing factors and the resulting stability characteristics are presented. A series of charts is included with which approximate stability characteristics may be rapidly estimated" (p. 1).
Date: November 17, 1936
Creator: Zimmerman, Charles H.
System: The UNT Digital Library
A Theory for Primary Failure of Straight Centrally Loaded Columns (open access)

A Theory for Primary Failure of Straight Centrally Loaded Columns

"A theory of primary failure of straight centrally loaded columns is presented. It is assumed that the column cross section and the load are constant throughout the length. Primary failure is defined as any type of failure in which the cross sections are translated, rotated, or translated and rotated but not distorted in their own planes" (p. 141).
Date: August 17, 1936
Creator: Lundquist, Eugene E. & Fligg, Claude M.
System: The UNT Digital Library