An Application of the Rocket-Propelled-Model Technique to the Investigation of Low-Lift Buffeting and the Results of Preliminary Tests (open access)

An Application of the Rocket-Propelled-Model Technique to the Investigation of Low-Lift Buffeting and the Results of Preliminary Tests

"The rocket-propelled-model technique has been applied to the investigation of low-lift buffeting. Results of preliminary tests show that severe buffeting, wing dropping, and normal-force changes occur almost simultaneously near zero lift over a Mach number range near 0.9 on unswept wings 12 percent thick. On unswept wings 7 percent thick, buffeting did not occur; however, mild wing dropping and normal-force changes were experienced" (p. 1).
Date: September 2, 1952
Creator: Mason, Homer P. & Gardner, William N.
System: The UNT Digital Library
A comparison of the experimental subsonic pressure distributions about several bodies of revolution with pressure distributions computed by means of the linearized theory (open access)

A comparison of the experimental subsonic pressure distributions about several bodies of revolution with pressure distributions computed by means of the linearized theory

Report presenting an analysis of the effects of compressibility on the pressure coefficients of several bodies of revolution by comparing experimentally determined pressure coefficients with corresponding pressure coefficients calculated by the use of linearized equations of compressible flow. The results indicated that the theoretical methods predict the subsonic pressure-coefficient changes over the central portion of the body but do not predict the pressure-coefficient changes near the nose.
Date: September 12, 1949
Creator: Matthews, Clarence W.
System: The UNT Digital Library
Flight Measurements of Lift and Drag for the Bell X-1 Research Airplane Having a 10-Percent-Thick Wing (open access)

Flight Measurements of Lift and Drag for the Bell X-1 Research Airplane Having a 10-Percent-Thick Wing

Report presenting drag coefficients during power-off transonic flight for the Bell X-1 airplane with a 10-percent-thick wing over a range of Mach numbers and pressure altitudes. The data was compared to an X-1 with an 8-percent-thick wing and a wind tunnel test with a 10-percent-thick wing. Information about necessary angle of attack, drag-rise Mach number, maximum lift-drag ratio, and drag coefficient at zero lift is provided.
Date: September 3, 1953
Creator: Saltzman, Edwin J.
System: The UNT Digital Library
Investigation of Flow Conditions and the Nature of the Wall-Constriction Effect Near and at Choking by Means of the Hydraulic Analogy (open access)

Investigation of Flow Conditions and the Nature of the Wall-Constriction Effect Near and at Choking by Means of the Hydraulic Analogy

Report presenting an investigation of the closed wind-tunnel phenomenon of choking and the wall-constriction effects in the subsonic Mach number range where supersonic Mach numbers appear using the hydraulic analogy. Application of the results to wind tunnel testing, the subsonic choking phenomena, and effects of the walls are described.
Date: September 1, 1948
Creator: Matthews, Clarence W. & Wright, Ray H.
System: The UNT Digital Library
Application of several methods for determining transfer functions and frequency response of aircraft from flight data (open access)

Application of several methods for determining transfer functions and frequency response of aircraft from flight data

Report presenting an investigation of the methods of analyzing longitudinal frequency-response characteristics of aircraft. The methods considered are analysis of sinusoidal response, analysis of transient response to harmonic content through determination of the Fourier integral, and analysis of the transient through the use of least-squares solutions of the coefficients of an assume equation for the transient time or frequency response.
Date: September 1953
Creator: Eggleston, John M. & Mathews, Charles W.
System: The UNT Digital Library
Tests of Lifting Surfaces on Conical and Cylindrical Portions of a Body at Subsonic Mach Numbers and at a Mach Number of 1.2 (open access)

Tests of Lifting Surfaces on Conical and Cylindrical Portions of a Body at Subsonic Mach Numbers and at a Mach Number of 1.2

Report presenting testing of low-aspect-ratio triangular-plan-form lifting surfaces located on conical and cylindrical portions of a body have been determined at Mach number 1.2 and several subsonic speeds to determine if the aerodynamic characteristics of these surfaces at supersonic speeds could be improved by locating them in the subsonic conical-flow field. Results regarding lift and drag coefficients and lift-curve slopes are provided.
Date: September 2, 1949
Creator: Osborne, Robert S. & Wright, John B.
System: The UNT Digital Library
Transonic Aerodynamic Characteristics of an NACA 64A006 Airfoil Section With a 15-Percent-Chord Leading-Edge Flap (open access)

Transonic Aerodynamic Characteristics of an NACA 64A006 Airfoil Section With a 15-Percent-Chord Leading-Edge Flap

Report presenting information about airfoil section normal-force, drag, pitching-moment, flap-normal-force, and hinge-moment characteristics at Mach numbers from 0.5 to 1.0 on an NACA 64A006 airfoil with 15-percent-chord leading-edge flap. Differing results were noted in the Mach ranges of 0.5 to 0.8 and over 0.8.
Date: September 1, 1953
Creator: Humphreys, Milton D.
System: The UNT Digital Library
Analysis of effect of variations in primary variables on time constant and turbine-inlet-temperature overshoot of turbojet engine (open access)

Analysis of effect of variations in primary variables on time constant and turbine-inlet-temperature overshoot of turbojet engine

From Introduction: "The design of turbojet-engine control systems is intimately related to the dynamic characteristics of the engine and has advanced to the stage where theoretically correct control constants can be determined for fixed dynamic properties (references 1 and 2). The use of the thermodynamic equations presupposes that the engine processes are quansi-static. Such an assumption is shown to be valid for a turbojet engine in references 3 and 4.
Date: September 1950
Creator: Heidmann, Marcus F.
System: The UNT Digital Library
Longitudinal frequency-response characteristics of a 35 degree swept-wing airplane as determined from flight measurements, including a method for the evaluation of transfer functions (open access)

Longitudinal frequency-response characteristics of a 35 degree swept-wing airplane as determined from flight measurements, including a method for the evaluation of transfer functions

Report presenting longitudinal frequency-response characteristics of a 35 degree swept-wing airplane computed from flight measurements. Also presented are pitching-velocity frequency responses to displacements of the adjustable stabilizer. Results regarding frequency-response curves, transfer functions, elevator effectiveness, altitude variations, and potential errors in data are provided.
Date: September 19, 1951
Creator: Triplett, William C. & Smith, G. Allan
System: The UNT Digital Library
Stability Derivatives of Cones at Supersonic Speeds (open access)

Stability Derivatives of Cones at Supersonic Speeds

"The aerodynamic stability derivatives due to pitching velocity and vertical acceleration are derived for circular cones traveling at supersonic speeds. Both first-order and a combination of first and second order potential solutions are obtained, and in calculations for the forces, no approximations are made to the tangency condition or the isentropic pressure relation. In addition, expressions for the forces, moments, and stability derivatives of arbitrary bodies of revolution are derived from Newtonian impact theory" (p. 1).
Date: September 1956
Creator: Tobak, Murray & Wehrend, William R.
System: The UNT Digital Library
On Laminar and Turbulent Friction (open access)

On Laminar and Turbulent Friction

Report deals, first with the theory of the laminar friction flow, where the basic concepts of Prandtl's boundary layer theory are represented from mathematical and physical points of view, and a method is indicated by means of which even more complicated cases can be treated with simple mathematical means, at least approximately. An attempt is also made to secure a basis for the computation of the turbulent friction by means of formulas through which the empirical laws of the turbulent pipe resistance can be applied to other problems on friction drag.
Date: September 1946
Creator: von Karman, T.
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
Longitudinal Stability and Control Characteristics at High Subsonic Speeds of Two Models of a Transonic Research Airplane With Wings and Horizontal Tails of Aspect Ratios 4.2 and 2 (open access)

Longitudinal Stability and Control Characteristics at High Subsonic Speeds of Two Models of a Transonic Research Airplane With Wings and Horizontal Tails of Aspect Ratios 4.2 and 2

Report discussing an investigation of two transonic research airplane models at a range of Mach numbers and Reynolds numbers. The main difference between the models was the aspect ratio of the horizontal tail. Results regarding the stability, control, incremental horizontal-tail characteristics, downwash, horizontal-tail load, stability factors, and a tailless configuration are provided.
Date: September 29, 1950
Creator: Luoma, Arvo A. & Wright, John B.
System: The UNT Digital Library
Collection of zero-lift drag data on bodies of revolution from free-flight investigations (open access)

Collection of zero-lift drag data on bodies of revolution from free-flight investigations

Report presenting a compilation of most of the zero-lift drag obtained from free-flight measurements on fin-stabilized bodies of revolution. Results regarding friction drag, base pressure and base drag, pressures on a forward facing step, and fin pressure drag are provided.
Date: September 3, 1957
Creator: Stoney, William E., Jr.
System: The UNT Digital Library