1,284 Matching Results

Search Results

Advanced search parameters have been applied.

NACA conference on Aerodynamic Problems of Transonic Airplane Design

Description: Compilation of the papers presented at a NACA conference on transonic airplane design, including stability and control and configurations with extreme sweep. From Introduction: "The purpose of this conference was to convey to those involved in the study of the aerodynamic problems of transonic aircraft these recent research results and to provide those attending an opportunity for discussion of the results."
Date: 1947-11-05/1947-11-06
Partner: UNT Libraries Government Documents Department

Theoretical additional span loading characteristics of wings with arbitrary sweep, aspect ratio, and taper ratio

Description: From Summary: "The Weissinger method for determining additional span loading has been used to find the lift-curve slope, spanwise center of pressure, aerodynamic center location, and span loading coefficients of untwisted and uncambered wings having a wide range of plan forms characterized by various combinations of sweep, aspect ratio, and taper ratio. The results are presented as variations of the aerodynamic characteristics with sweep angle for various values of aspect ratio and taper ratio. Methods are also included for determining induced drag and the approximate effects of compressibility."
Date: December 1947
Creator: DeYoung, John
Partner: UNT Libraries Government Documents Department

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-curve slope are taken into account by the procedure. The method presented can also be used to calculate the downwash in the vertical center of the wake of a wing which has arbitrary spanwise loading."
Date: September 22, 1950
Creator: DeYoung, John
Partner: UNT Libraries Government Documents Department

Theoretical antisymmetric span loading for wings of arbitrary plan form at subsonic speeds

Description: A simplified lifting-surface theory that includes effects of compressibility and spanwise variation of section lift-curve slope is used to provide charts with which antisymmetric loading due to arbitrary antisymmetric angle of attack can be found for wings having symmetric plan forms with a constant spanwise sweep angle of the quarter-chord line. Consideration is given to the flexible wing in roll. Aerodynamic characteristics due to rolling, deflected ailerons, and sideslip of wings with dihedral are considered. Solutions are presented for straight-tapered wings for a range of swept plan forms.
Date: December 22, 1949
Creator: DeYoung, John
Partner: UNT Libraries Government Documents Department

Spanwise loading for wings and control surfaces of low aspect ratio

Description: Report presenting a theory based on the principle of downwash and boundary conditions, which will predict the spanwise loading due to arbitrary spanwise angle-of-attack distribution, including uniform angle of attack, that induced by rolling, spanwise variation of twist or camber, and that due to deflection of arbitrary control surfaces of low aspect ratio. For plan forms with unswept trailing edges that the spanwise loading distribution, only the slope of the region at the wing trailing edge has an effect.
Date: January 1950
Creator: DeYoung, John
Partner: UNT Libraries Government Documents Department

The wave drag of arbitrary configurations in linearized flow as determined by areas and forces in oblique planes

Description: From Summary: "The wave drag, based on linearized theory, of any lifting or non-lifting planar or nonplanar object in a steady supersonic flow is shown to be identical at a fixed Mach number to the average wave drag of a series of equivalent bodies of revolution. The streamwise gradient of area, measured normal to the free stream, at a section of each of these equivalent bodies of revolution is given by the sum of two quantities: 1. the streamwise gradient of area, measured in parallel oblique planes tangent to the Mach cones, along the given object. 2. A term proportional to the resultant force on the object measured in the same oblique planes."
Date: March 24, 1955
Creator: Lomax, Harvard
Partner: UNT Libraries Government Documents Department

Applications of Modern Hydrodynamics to Aeronautics. Part 1: Fundamental Concepts and the Most Important Theorems. Part 2: Applications

Description: A discussion of the principles of hydrodynamics of nonviscous fluids in the case of motion of solid bodies in a fluid is presented. Formulae are derived to demonstrate the transition from the fluid surface to a corresponding 'control surface'. The external forces are compounded of the fluid pressures on the control surface and the forces which are exercised on the fluid by any solid bodies which may be inside of the control surfaces. Illustrations of these formulae as applied to the acquisition of transformations from a known simple flow to new types of flow for other boundaries are given. Theoretical and experimental investigations of models of airship bodies are presented.
Date: 1979?~
Creator: Prandtl, L.
Partner: UNT Libraries Government Documents Department

An analysis of the errors in curve-fitting problems with an application to the calculation of stability parameters from flight data

Description: From Introduction: "It is shown in the body of this report that the solution to the error problem depends upon a more or less arbitrary definition, the only criterion as to the choice of the definition being the usefulness of the solution to which it leads. In this respect, it may be said of the method derived herein that it is not difficult to apply and appears to lead reasonable values of the errors."
Date: November 1952
Creator: Shinbrot, Marvin
Partner: UNT Libraries Government Documents Department

On the Use of a Damped Sine-Wave Elevator Motion for Computing the Design Maneuvering Horizontal-Tail Load

Description: Note presenting a damped sine-wave elevator motion used as a basis for computing the design maneuvering load on the horizontal tail. The results indicated that the maneuvering tail-load variation computed by operational methods with the assumed damped sine-wave elevator motion agreed closely with the loads computed by a method currently used by the US Air Force.
Date: January 1953
Creator: Sadoff, Melvin
Partner: UNT Libraries Government Documents Department

Preliminary Investigation of a Submerged Inlet and a Nose Inlet in the Transonic Flight Range With Free-Fall Models

Description: Memorandum presenting an NACA submerged inlet and an NACA series I nose inlet installed in bodies of 12.4 fineness ratio to determine the drag and pressure-recovery characteristics of each body-inlet configuration. The tests were conducted with large-scale free-fall models released at an altitude of 40,000 feet, for mass-flow ratios of about 0.4 and 0.7 over a Mach number range of about 0.70 to 1.10. Results regarding drag and ram-recovery ratios are provided.
Date: June 18, 1951
Creator: Selna, James
Partner: UNT Libraries Government Documents Department

Flight Measurements of the Horizontal-Tail Loads on a Swept-Wing Fighter Airplane at Transonic Speeds

Description: Memorandum presenting flight tests on a swept-wing fighter airplane at a range of Mach numbers, which indicate the critical flight regions for balancing, maneuvering, and buffeting horizontal-tail loads. The critical balancing tail loads were found to occur at the highest test Mach number of about 1.03 at the highest airplane load factor. Results regarding balancing tail loads, maneuvering tail loads in elevator-pulse maneuvers, maneuvering tail loads in pitch-up maneuvers, buffet tail loads, and tail-load distributions are provided.
Date: November 6, 1953
Creator: Sadoff, Melvin
Partner: UNT Libraries Government Documents Department

An Investigation of a Thermal Ice-Prevention System for a C-46 Cargo Airplane 5: Effect of Thermal System on Airplane Cruise Performance

Description: Report presenting flight tests conducted to evaluate the effect of a thermal ice prevention system on the aerodynamic performance of a C-46 cargo airplane. The installation of the thermal ice-prevention system was found to reduce the indicated airspeed by about 6 miles per hour. Results regarding the overall performance change resulting from the installation of the thermal system, reduction of power attributed to heat-exchanger exhaust-gas back pressure, reduction of power attributed to the internal and external drag of the thermal system, and the additional airplane gross weight attributed to the thermal system are provided.
Date: May 1945
Creator: Selna, James
Partner: UNT Libraries Government Documents Department

An Investigation of a Thermal Ice-Prevention System for a C-46 Cargo Airplane 2: The Design, Construction, and Preliminary Tests of the Exhaust-Air Heat Exchanger

Description: Report presenting an investigation of an exhaust-air heat exchanger, which has been designed, constructed, and flight-tested for a C-46 cargo airplane. The primary purpose of the investigation was to provide the C-46 airplane with a satisfactory source of heated air and to continue the development of the heat exchanger as a part of thermal ice-prevention equipment. Results indicated that the required thermal output and desired air-temperature rise have been achieved and that the exchanger is suitable for use in the C-46 airplane.
Date: February 1945
Creator: Jackson, Richard
Partner: UNT Libraries Government Documents Department

Sideslip Angles and Vertical-Tail Loads Developed by Periodic Control Deflections

Description: Note presenting a consideration of dynamic maneuvers consisting of periodic rudder and aileron control deflections with respect to the maximum sideslip angles developed and the position of the rudder at the time of maximum sideslip. A method is also given for computing the maximum sideslip angles when the forces and moments are nonlinear functions of the sideslip.
Date: January 1948
Creator: Lomax, Harvard
Partner: UNT Libraries Government Documents Department

Theoretical Investigation of the Performance of Proportional Navigation Guidance Systems: Effect of Missile Configuration on the Speed of Response

Description: Memorandum presenting a comparison of the maximum speed of response that can be attained by three missile configurations, a variable-incidence-wing, a canard, and a tail-control, in combination with a particular proportional navigation guidance system. The configuration that allows the most rapid overall guidance-system response depends on the control-system characteristics. Results regarding the rate-only feedback and rate and normal acceleration feedback are provided.
Date: January 19, 1953
Creator: Abramovitz, Marvin
Partner: UNT Libraries Government Documents Department

Theoretical Investigation of the Performance of Proportional Navigation Guidance Systems: Effect of Method of Positioning the Radar Antenna on the Speed of Response

Description: Memorandum presenting a linear theoretical analysis made of the performance of three proportional navigation guidance systems installed in a given supersonic, variable-incidence, boost-glide, antiaircraft missile at Mach numbers of 2.7 and 1.3. Three guidance systems are compared on the basis of the maximum obtainable speed of response of the missile and guidance-system combination consistent with adequate stability. Results regarding the effect of method of positioning the radar antenna on the speed of response, effect of Mach number on response, and effect of networks are provided.
Date: August 13, 1952
Creator: Abramovitz, Marvin
Partner: UNT Libraries Government Documents Department

The Theoretical Lift of Flat Swept-Back Wings at Supersonic Speeds

Description: Note presenting an application of the method of superposition of linearized conical flows to the calculatin of the aerodynamic properties of thin, flat, swept-back wings at an angle of attack. Various cases are distinguished, depending on the sweep of the leading and trailing edges relative to their respective Mach lines. The results of the calculations emphasize the indications of the theory that the determining factor in the aerodynamic performance of wings is the disposition of area relative to the Mach lines.
Date: March 1948
Creator: Cohen, Doris
Partner: UNT Libraries Government Documents Department

Icing Properties of Noncyclonic Winter Stratus Clouds

Description: Note presenting measurements of the vertical distribution of liquid water concentration and drop size in winter stratus clouds in the absence of significant cyclonic or frontal activity. The observations indicate that the clouds are formed by turbulent mixing of the lower layers of the atmosphere, resulting in a region of constant specific humidity and adiabatic lapse rates. Calculations based on the observations were used to construct a graph that gives the liquid water concentration in terms of the temperature at the cloud base and the height above the base.
Date: September 1947
Creator: Lewis, William
Partner: UNT Libraries Government Documents Department

Nonlifting Wing-Body Combinations With Certain Geometric Restraints Having Minimum Wave Drag at Low Supersonic Speeds

Description: "Several variational problems involving optimum wing and body combinations having minimum wave drag for different kinds of geometrical restraints are analyzed. Particular attention is paid to the effect on the wave drag of shortening the fuselage and, for slender axially symmetric bodies, the effect of fixing the fuselage diameter at several points or even of fixing whole portions of its shape" (p. 113).
Date: August 4, 1955
Creator: Lomax, Harvard
Partner: UNT Libraries Government Documents Department

On the Use of the Indicial-Function Concept in the Analysis of Unsteady Motions of Wings and Wing-Tail Combinations

Description: "The concept of indicial aerodynamic functions is applied to the analysis of the short-period pitching mode of aircraft. By the use of simple physical relationships associated with the indicial-function relationships concept, quantitative studies are made of the separate effects on the damping in pitch of changes in Mach number, aspect ratio, plan-form shape, and frequency. The concept is further shown to be of value in depicting physically the induced effects on a tail surface which follows in the wake of a starting forward surface" (p. 1).
Date: 1954
Creator: Tobak, Murray
Partner: UNT Libraries Government Documents Department

The Prospects for Laminar Flow on Hypersonic Airplanes

Description: The factors which affect the extent of laminar flow on airplanes for hypersonic flight are discussed on the basis of the available data. Factors considered include flight Reynolds number, surface roughness, angle of attack, angle of leading-edge sweepback, and aerodynamic interference. Test data are presented for one complete configuration.
Date: June 27, 1958
Creator: Seiff, Alvin
Partner: UNT Libraries Government Documents Department