Analysis of a Form of Peak Holding Control (open access)

Analysis of a Form of Peak Holding Control

From Introduction: "The general objective of this report is a study of the characteristics of the described form of peak holding control. The control has not yet been used in experimental turbojet-engine study.This study is concerned with only one method of extracting the maximum amount of information from a peak output for the purpose of maintaining that peak. The criteria sought in this control process are: maintenance of peak average output, minimum duration of time in undesirable operation, quickness in response to command to reach peak condition, least amount of excursion in the undesirable region, and type of stability."
Date: March 30, 1956
Creator: Delio, G. J.
System: The UNT Digital Library
Evaluation of three methods for determining dynamic characteristics of a turbojet engine (open access)

Evaluation of three methods for determining dynamic characteristics of a turbojet engine

Report presenting transient data from approximate step and sinusoidal disturbances of fuel flow on a turbojet engine operated at one constant simulated altitude and flight condition. Results regarding coefficients of differential equations, Fourier representation, frequency response, transient analysis, and a comparison of the various analytical methods are provided.
Date: February 1952
Creator: Delio, Gene J.
System: The UNT Digital Library
Theoretical and analog studies of the effects of nonlinear stability derivatives on the longitudinal motions of an aircraft in response to step control deflections and to the influence of proportional automatic control (open access)

Theoretical and analog studies of the effects of nonlinear stability derivatives on the longitudinal motions of an aircraft in response to step control deflections and to the influence of proportional automatic control

Through theoretical and analog results the effects of two nonlinear stability derivatives on the longitudinal motions of an aircraft have been investigated. Nonlinear functions of pitching-moment and lift coefficients with angle of attack were considered. Analog results of aircraft motions in response to step elevator deflections and to the action of the proportional control systems are presented. The occurrence of continuous hunting oscillations was predicted and demonstrated for the attitude stabilization system with proportional control for certain nonlinear pitching-moment variations and autopilot adjustments.
Date: December 29, 1950
Creator: Curfman, Howard J., Jr.
System: The UNT Digital Library
Lift and Pitching Moment at Supersonic Speeds Due to Constant Vertical Acceleration for Thin Sweptback Tapered Wings With Streamwise Tips: Supersonic Leading and Trailing Edges (open access)

Lift and Pitching Moment at Supersonic Speeds Due to Constant Vertical Acceleration for Thin Sweptback Tapered Wings With Streamwise Tips: Supersonic Leading and Trailing Edges

Note presenting the nondimensional lift derivative and the corresponding pitching-moment derivative resulting from constant vertical acceleration as evaluated for a family of thin sweptback tapered wings with streamwise tips traveling at supersonic speeds. The analysis is applicable at those speeds for which the wing leading and trailing edges are both supersonic, provided that the Mach lines from the wing apex intersect the trailing edge and that the Mach line from the leading edge of one tip does not intersect the remote half-wing.
Date: July 1954
Creator: Cole, Isabella J. & Margolis, Kenneth
System: The UNT Digital Library
Propeller Flight Investigation to Determine the Effects of Blade Loading (open access)

Propeller Flight Investigation to Determine the Effects of Blade Loading

Note presenting a flight investigation of a three-blade propeller in climb and at high speed to determine the effects of blade power loading. Increasing the blade power coefficient from 0.06 to 0.09 was found to increase the efficiency approximately 8 percent at an airplane Mach number of 0.7 and a propeller-tip Mach number of 1.13. In climb, an increase in power loading over the range of blade power coefficients investigated was shown to reduce efficiency, as a consequence of increased induced drag losses.
Date: January 1950
Creator: Hammack, Jerome B. & Vogeley, A. W.
System: The UNT Digital Library
The effects of compressibility on the pressures on a body of revolution and on the aerodynamic characteristics of a wing-nacelle combination consisting of the body of revolution mounted on a swept-back wing (open access)

The effects of compressibility on the pressures on a body of revolution and on the aerodynamic characteristics of a wing-nacelle combination consisting of the body of revolution mounted on a swept-back wing

Memorandum presenting an investigation of the effects of compressibility on the forces, pitching moments, and surface pressures on a wing-nacelle combination. The leading edge of the wing was swept back 37.25 degrees and the nacelle was a body of revolution with a fineness ratio of 6.5. The effects of compressibility on the surface pressures and on the drag of a body of revolution similar to the nacelle were also determined.
Date: July 26, 1950
Creator: Boltz, Frederick W. & Beam, Benjamin H.
System: The UNT Digital Library
Glues Used in Airplane Parts (open access)

Glues Used in Airplane Parts

This report was prepared for the National Advisory Committee for Aeronautics and presents the results of investigations conducted by the Forest Products Laboratory of the United States Forest Service on the manufacture, preparation, application, testing and physical properties of the different types of glues used in wood airplane parts.
Date: 1920
Creator: Allen, S. W. & Truax, T. R.
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

In the process of analyzing the longitudinal frequency-response characteristics of aircraft, information on some of the methods of analysis has been obtained by the Langley Aeronautical Laboratory of the National Advisory Committee for Aeronautics. In the investigation of these methods, the practical applications and limitations were stressed. In general, the methods considered may be classed as: (1) analysis of sinusoidal response, (2) analysis of transient response as to harmonic content through determination of the Fourier integral by manual or machine methods, and (3) analysis of the transient through the use of least-squares solutions of the coefficients of an assumed equation for either the transient time response or frequency response (sometimes referred to as curve-fitting methods). (author).
Date: 1954
Creator: Eggleston, John M. & Mathews, Charles W.
System: The UNT Digital Library
Aerodynamic Characteristics in Pitch and Sideslip at High Subsonic Speeds of a 1/14-Scale Model of the Grumman XF104 Airplane with Wing Sweepback of 42.5 Degrees (open access)

Aerodynamic Characteristics in Pitch and Sideslip at High Subsonic Speeds of a 1/14-Scale Model of the Grumman XF104 Airplane with Wing Sweepback of 42.5 Degrees

"An investigation has been made at high subsonic speeds of the aerodynamic characteristics in pitch and sideslip of a 1/l4-scale model of the Grumman XF10F airplane with a wing sweepback angle of 42.5. The longitudinal stability characteristics (with the horizontal tail fixed) indicate a pitch-up near the stall; however, this was somewhat alleviated by the addition of fins to the side of the fuselage below the horizontal tail. The original model configuration became directionally unstable for small sideslip angles at Mach numbers above 0.8; however, the instability was eliminated by several different modifications" (p. 1).
Date: August 18, 1953
Creator: Kuhn, Richard E. & Draper, John W.
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
Altitude-Wind-Tunnel Investigation of Performance of Several Propellers on YP-47M Airplane at High Blade Loading, 1, Aeroproducts H20C-162-X11M2 Four-Blade Propeller (open access)

Altitude-Wind-Tunnel Investigation of Performance of Several Propellers on YP-47M Airplane at High Blade Loading, 1, Aeroproducts H20C-162-X11M2 Four-Blade Propeller

"An investigation was made in the Cleveland Altitude wind tunnel to determine the performance of an Aeroproducts H20C-162-X11M2 four-blade propeller on a YP-47M airplane at high blade loadings and high engine powers. The propeller characteristics were obtained for a range of power coefficients from 0.30 to 1.00 at free-stream Mach numbers of 0.40 and 0.50. The results of the force measurements are indicative only of trends in propeller efficiency with changes in power coefficient and advance-diameter ratio because unknown interference effects existed during the investigation" (p. 1).
Date: October 11, 1946
Creator: Saari, Martin J. & Wallner, Lewis E.
System: The UNT Digital Library
Pressure distribution over a sharp-nose body of revolution at transonic speeds by the NACA wing-flow method (open access)

Pressure distribution over a sharp-nose body of revolution at transonic speeds by the NACA wing-flow method

Report presenting an investigation to obtain the pressure distribution over a sharp-nose body of revolution with a circular-arc profile and fineness ratio 6 at transonic speeds using the NACA wing-flow method. Results regarding the variation of pressure coefficient with Mach number, pressure distributions along the body axis, pressure drag, and effects of interference and horizontal gradient are provided.
Date: March 5, 1948
Creator: Danforth, Edward C. B. & Johnston, J. Ford
System: The UNT Digital Library
Fairing Compositions for Aircraft Surfaces (open access)

Fairing Compositions for Aircraft Surfaces

Note presenting fairing compositions applied to aircraft surfaces, welds and junctions of metal plates, and rivet depressions to improve the aerodynamic efficiency of the airplane at high speeds. A method is described for formulating fairing compositions which have, within limits, desired coefficients of thermal expansion. Results regarding water-immersion tests, thermal expansion and softening temperature, temperature-cycle tests, and density are provided.
Date: November 1944
Creator: Turner, Philip S.; Doran, Jewel & Reinhart, Frank W.
System: The UNT Digital Library
Annual Report for the National Advisory Committee for Aeronautics (10th) Administrative Report Including Technical Reports Nos. 186 to 209 (open access)

Annual Report for the National Advisory Committee for Aeronautics (10th) Administrative Report Including Technical Reports Nos. 186 to 209

Report includes the National Advisory Committee for Aeronautics letter of submittal to the president, congressional report, summaries of the committee's activities and research accomplished, bibliographies, and financial report.
Date: 1925
Creator: United States. National Advisory Committee for Aeronautics.
System: The UNT Digital Library
Compressibility Factor, Density, Specific Heat, Enthalpy, Entropy, Free-Energy Function, Viscosity, and Thermal Conductivity of Steam (open access)

Compressibility Factor, Density, Specific Heat, Enthalpy, Entropy, Free-Energy Function, Viscosity, and Thermal Conductivity of Steam

Note presenting tables of thermal properties of stream that have been prepared in an NBS-NACA series. They include, for real gas, the compressibility factor, the density, the specific heat at constant pressure, the enthalpy, the entropy, the free-energy function, the viscosity, and the thermal conductivity.
Date: August 1956
Creator: Fano, Lilla; Hubbell, John H. & Beckett, Charles W.
System: The UNT Digital Library
Results of preliminary flight investigation of aerodynamic characteristics of the NACA two-stage supersonic research model RM-1 stabilized in roll at transonic and supersonic velocities (open access)

Results of preliminary flight investigation of aerodynamic characteristics of the NACA two-stage supersonic research model RM-1 stabilized in roll at transonic and supersonic velocities

Report presenting the design of a two-stage, solid-fuel, rocket-propelled, general research pilotless aircraft suitable for investigating stability and control at supersonic velocities. The flight test investigation is described and information is provided for zero-length launchers and operational flight-test techniques of two-stage rockets. Results regarding launching characteristics and lateral stabilization and control flight tests are provided.
Date: March 19, 1947
Creator: Pitkin, Marvin; Garner, William N. & Curfman, Howard J., Jr.
System: The UNT Digital Library
A theoretical investigation of the aerodynamics of wing-tail combinations performing time-dependent motions at supersonic speeds (open access)

A theoretical investigation of the aerodynamics of wing-tail combinations performing time-dependent motions at supersonic speeds

Report presenting a theoretical investigation of the contribution of horizontal tails to the lift and pitching moment due to angle of attack, a constant rate of pitch, and a constant vertical acceleration. Methods for calculating the flow fields behind wings with constant vertical acceleration are developed.
Date: May 1954
Creator: Martin, John C.; Diederich, Margaret S. & Bobbitt, Percy J.
System: The UNT Digital Library
Method of Estimating the Stick-Fixed Longitudinal Stability of Wing-Fuselage Configurations Having Unswept or Swept Wings (open access)

Method of Estimating the Stick-Fixed Longitudinal Stability of Wing-Fuselage Configurations Having Unswept or Swept Wings

Memorandum presenting a method for calculating the stick-fixed longitudinal stability of a wing-fuselage configuration at subcritical Mach numbers. The method applies to unswept- and swept-wing configurations. The stability parameters estimated by the method show reasonable agreement with the experimental values for the 23 configurations used in the comparison.
Date: January 22, 1952
Creator: McLaughlin, Milton D.
System: The UNT Digital Library
NACA Transonic Wing-Tunnel Test Sections (open access)

NACA Transonic Wing-Tunnel Test Sections

Memorandum presenting an approximate subsonic theory developed for the solid blockage interference in circular wind tunnels with walls slotted in the direction of flow. The theory indicated the possibility of obtaining zero blockage interference. Tests in a circular slotted tunnel based on the theory confirmed the theoretical predictions.
Date: October 25, 1948
Creator: Wright, Ray H. & Ward, Vernon G.
System: The UNT Digital Library
Effects of External Store Mounting on the Buffet, Trim, and Drag Characteristics of Rocket-Powered Fuselage and Store Combinations Between Mach Numbers of 0.7 and 1.4 (open access)

Effects of External Store Mounting on the Buffet, Trim, and Drag Characteristics of Rocket-Powered Fuselage and Store Combinations Between Mach Numbers of 0.7 and 1.4

Memorandum presenting an investigation made of the effects of store mounting on the buffet, trim, and drag characteristics of fuselage-mounted external stores between Mach numbers of 0.7 and 1.4 by the use of the rocket-propelled-model technique. Results of the tests are presented in the incremental accelerations in the stores due to buffeting, trim normal- and side-force coefficients, tail helix angles, and drag coefficients plotted against Mach number.
Date: December 10, 1953
Creator: Mason, Homer P.
System: The UNT Digital Library
Free-flight transonic model investigation of jet effects on a fighter-type configuration employing a tail boom and three horizontal-tail positions (open access)

Free-flight transonic model investigation of jet effects on a fighter-type configuration employing a tail boom and three horizontal-tail positions

Report presenting the results of a limited research program initiated to study the effects of a hot propulsive jet on the longitudinal stability characteristics of a fighter-type airplane configuration. The data was obtained from a rocket-boosted free-flight model investigation over a range of Mach numbers using four models that differed only in the position and size of the horizontal tail. Results regarding the time histories, trim, normal force, pitching moment, aerodynamic-center location, dynamic stability, trim drag, and pressure data are provided.
Date: February 20, 1958
Creator: Jackson, Bruce G.
System: The UNT Digital Library
Dynamic Loads on Airplane Structures During Landing (open access)

Dynamic Loads on Airplane Structures During Landing

Report presenting the application of transient theory to the rational determination of dynamic loads on airplane structures during initial landing impact. Simplified procedures are described by which the distribution of the maximum attainable value of the dynamic stresses in the structure may be obtained.
Date: October 1944
Creator: Biot, M. A. & Bisplinghoff, R. L.
System: The UNT Digital Library
Time-dependent downwash at the tail and the pitching moment due to normal acceleration at supersonic speeds (open access)

Time-dependent downwash at the tail and the pitching moment due to normal acceleration at supersonic speeds

Report presenting an analysis of the time-dependent downwash behind a wing in a supersonic stream when the angle of attack varies linearly with time. The result is applied to the calculation of the contribution of the horizontal tail to the pitching moment and lift due to normal acceleration of the airplane. Results regarding downwash charts and some limitations on the results are provided.
Date: February 1950
Creator: Ribner, Herbert S.
System: The UNT Digital Library