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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

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

Flight Tests of Thermal Ice-Prevention Equipment on a Lockheed 12A Airplane

Description: Report presenting a description of the development of thermal ice-prevention equipment by the application of a heated-air ice-prevention system to a Lockheed 12A airplane. Test data indicated that thermal ice-prevention equipment is practical and that the method of utilizing the exhaust gases as a source of heat is satisfactory.
Date: November 1943
Creator: Scherrer, Richard
Partner: UNT Libraries Government Documents Department

On the Minimization of Airplane Responses to Random Gusts

Description: Note presenting a theoretical study of the motions experienced by aircraft in response to sharp-edge, harmonic, and random gusts. These are compared with approximate solutions based on commonly used assumptions, and the validity of each of the assumptions is assessed.
Date: October 1957
Creator: Tobak, Murray
Partner: UNT Libraries Government Documents Department

An Analysis of Supersonic Flow in the Region of the Leading Edge of Curved Airfoils, Including Charts for Determining Surface-Pressure Gradient and Shock-Wave Curvature

Description: Note presenting an investigation of the inviscid flow in the region of the leading edge of curved airfoils with attached shock waves. Tables and charts are presented for determining the surface-pressure gradient and the shock-wave curvature in supersonic flow of an ideal diatomic gas. An approximate procedure for determining the flow field a short distance downstream of the leading edge is also presented.
Date: June 1952
Creator: Kraus, Samuel
Partner: UNT Libraries Government Documents Department

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

Description: "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
Partner: UNT Libraries Government Documents Department

A Survey of Methods for Determining Stability Parameters of an Airplane From Dynamic Flight Measurements

Description: Note presenting a discussion of various methods of reducing to stability parameter form the response to sinusoidal and transient disturbances, using the simplified longitudinal motion of an idealized airplane as an illustrative example. Most of this report is concerned with methods of determining transfer-function coefficients rather than stability derivatives. Examples are provided for a simplified case of longitudinal motion, but the methods presented are applicable to other, more complicated types of motion.
Date: April 1951
Creator: Greenberg, Harry
Partner: UNT Libraries Government Documents Department

The Low-Speed Lift and Drag Characteristics of a Series of Airplane Models Having Triangular or Modified Triangular Wings

Description: Memorandum summarizing the lift and drag characteristics of a series of five low-aspect-ratio triangular-wing or modified triangular-wing airplane models. The series consists of three triangular wings of aspect ratios 2, 3, and 4 and two modified triangular wings of aspect ratio 2 with taper ratios of 0.20 and 0.33. The experimental lift and drag characteristics of the five models are compared with existing theory.
Date: June 15, 1953
Creator: Graham, David
Partner: UNT Libraries Government Documents Department

Damping in Pitch of Low-Aspect-Ratio Wings at Subsonic and Supersonic Speeds

Description: Memorandum presenting the application of the concept of indicial functions to the analysis of the aerodynamic phenomena associated with the short-period pitching mode of wings in subsonic and supersonic flight. Simple physical relationships are pointed out and are used to study the effect on the rotary-damping-moment coefficient of changes in center-of-gravity position, Mach number, aspect ratio, plan form, frequency, and thickness.
Date: April 8, 1953
Creator: Tobak, Murray
Partner: UNT Libraries Government Documents Department

A Flight Investigation of the Meteorological Conditions Conducive to the Formation of Ice on Airplanes

Description: Note presenting data from flight measurements of the meteorological factors related to the intensity of icing conditions. The physical factors that establish the distribution of liquid water in clouds of various types are discussed and the results of the analysis are used to formulate certain rules for the forecasting of icing intensity. Discussion of the results includes the problem of forecasting icing conditions and the problem of defining the physical characteristics of icing conditions for the purpose of the design of ice-protection equipment.
Date: August 1947
Creator: Lewis, William
Partner: UNT Libraries Government Documents Department

An Investigation at Subsonic Speeds of the Rolling Effectiveness of a Small Perforated Spoiler on a Wing Having 45 Degrees of Sweepback

Description: Memorandum presenting an investigation of the rolling effectiveness of a partial-span, perforated spoiler on a wing with 45 degrees of sweepback at Mach numbers from 0.25 to 0.96. The effects of the spoiler on the lift, drag, and pitching moment were also determined. Results regarding Reynolds number, Mach number, and predicted rate of roll are provided.
Date: September 15, 1952
Creator: Bandettini, Angelo
Partner: UNT Libraries Government Documents Department