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Ice Prevention on Aircraft by Means of Engine Exhaust Heat and a Technical Study of Heat Transmission From a Clark Y Airfoil

Description: "This investigation was conducted to study the practicability of employing heat as a means of preventing the formation of ice on airplane wings. The report relates essentially to technical problems regarding the extraction of heat from the exhaust gases and its proper distribution over the exposed surfaces. In this connection a separate study has been made to determine the variation of the coefficient of heat transmission along the chord of a Clark Y airfoil. Experiments on ice prevention both … more
Date: June 12, 1931
Creator: Theodorsen, Theodore & Clay, William C.
Partner: UNT Libraries Government Documents Department
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A flight evaluation of the longitudinal stability characteristics associated with the pitch-up of a swept-wing airplane in maneuvering flight at transonic speeds

Description: This report presents the results of flight measurements of longitudinal stability and control characteristics made on a swept-wing jet aircraft to determine the origin of the pitch-up encountered in maneuvering flight at transonic speeds. For this purpose measurements were made of elevator angle, tail angle of attack, and wing-fuselage pitching moments (obtained from measurements of the balancing tail loads).
Date: September 12, 1951
Creator: Anderson, Seth B. & Bray, Richard S.
Partner: UNT Libraries Government Documents Department
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Extrapolation techniques applied to matrix methods in neutron diffusion problems

Description: "A general matrix method is developed for the solution of characteristic-value problems of the type arising in many physical applications. The scheme employed is essentially that of Gauss and Seidel with appropriate modifications needed to make it applicable to characteristic-value problems. An iterative procedure produces a sequence of estimates to the answer; and extrapolation techniques, based upon previous behavior of iterants, are utilized in speeding convergence. Theoretically sound limit… more
Date: May 12, 1955
Creator: McCready, Robert R.
Partner: UNT Libraries Government Documents Department
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Analysis and Calculation by Integral Methods of Laminar Compressible Boundary-Layer With Heat Transfer and With and Without Pressure Gradient

Description: From Introduction: "The purpose of the present report is to present a comprehensive summary of theoretical investigations of comprehensible laminar boundary layers which have been carried out since 1949 at the Polytechnic Institute of Brooklyn under the sponsorship and with the financial assistance of the National Advisory Committee for Aeronautics. The results of these investigations are contained primarily in references 1 to 7."
Date: April 12, 1955
Creator: Morduchow, Morris
Partner: UNT Libraries Government Documents Department
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The Theory of Propellers 4: Thrust, Energy, and Efficiency Formulas for Single and Dual Rotating Propellers With Ideal Circulation Distribution

Description: "Simple and exact expressions are given for the efficiency of single and dual rotating propellers with ideal circulation distribution as given by the Goldstein functions for single-rotating propellers and by the new functions for dual-rotating propellers from part I of the present series. The efficiency is shown to depend primarily on a defined load factor and, to a very small extent, on an axial loss factor. Tables and charts are included for practical use of the results. The present paper is … more
Date: October 12, 1944
Creator: Theodorsen, Theodore
Partner: UNT Libraries Government Documents Department
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Effect of hinge-moment parameters on elevator stick forces in rapid maneuvers

Description: "The importance of the stick force per unit normal acceleration as a criterion of longitudinal stability and the critical dependence of this gradient on elevator hinge-moment parameters have been shown in previous reports. The present report continues the investigation with special reference to transient effects for maneuvers of short duration" (p. 449).
Date: October 12, 1944
Creator: Jones, Robert T. & Greenberg, Harry
Partner: UNT Libraries Government Documents Department
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On the flow of a compressible fluid by the hodograph method 1: unification and extension of present-day results

Description: From Summary: "Elementary basic solutions of the equations of motion of a compressible fluid in the hodograph variables are developed and used to provide a basis for comparison, in the form of velocity correction formulas, of corresponding compressible and incompressible flows. The known approximate results of Chaplygin, Von Karman and Tsien, Temple and Yarwood, and Prandtl and Glauert are unified by means of the analysis of the present paper. Two new types of approximations, obtained from the … more
Date: January 12, 1944
Creator: Garrick, I. E. & Kaplan, Carl
Partner: UNT Libraries Government Documents Department
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A graphical method of determining pressure distribution in two-dimensional flow

Description: By a generalization of the Joukowski method, a procedure is developed for effecting localized modifications of airfoil shapes and for determining graphically the resultant changes in the pressure distribution. The application of the procedure to the determination of the pressure distribution over airfoils of original design is demonstrated. Formulas for the lift, the moment, and the aerodynamic center are also given.
Date: November 12, 1940
Creator: Jones, Robert T. & Cohen, Doris
Partner: UNT Libraries Government Documents Department
open access

Sound-Level Measurements of a Light Airplane Modified to Reduce Noise Reaching the Ground

Description: "An Army liaison-type airplane, representative of personal airplanes in the 150 to 200 horsepower class, has been modified to reduce propeller and engine noise according to known principles of airplane-noise reduction. Noise-level measurements demonstrate that, with reference to an observer on the ground, a noisy airplane of this class can be made quiet -- perhaps more quiet than necessary. In order to avoid extreme and unnecessary modifications, acceptable noise levels must be determined" (p. … more
Date: February 12, 1948
Creator: Vogeley, A. W.
Partner: UNT Libraries Government Documents Department
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Appreciation and Prediction of Flying Qualities

Description: "The material given in this report summarizes some of the results of recent research that will aid the designers of an airplane in selecting or modifying a configuration to provide satisfactory stability and control characteristics. The requirements of the NACA for satisfactory flying qualities, which specify the important stability and control characteristics of an airplane from the pilot's standpoint, are used as the main topics of the report. A discussion is given of the reasons for the requ… more
Date: April 12, 1948
Creator: Phillips, William H.
Partner: UNT Libraries Government Documents Department
open access

Dislocation Theory of the Fatigue of Metals

Description: "A dislocation theory of fatigue failure for annealed solid solutions is presented. On the basis of this theory, an equation giving the dependence of the number of cycles for failure on the stress, the temperature, the material parameters, and the frequency is derived for uniformly stressed specimens. The equation is in quantitative agreement with the data" (p. 183).
Date: September 12, 1947
Creator: Machlin, E. S.
Partner: UNT Libraries Government Documents Department
open access

Damping in pitch and roll of triangular wings at supersonic speeds

Description: A method is derived for calculating the damping coefficients in pitch and roll for a series of triangular wings and a restricted series of sweptback wings at supersonic speeds. The elementary "supersonic source" solution of the linearized equation of motion is used to find the potential function of a line of doublets, and the flows are obtained by surface distributions of these doublet lines. The damping derivatives for triangular wings are found to be a function of the ratio of the tangent of … more
Date: December 12, 1947
Creator: Brown, Clinton E. & Adams, Mac C.
Partner: UNT Libraries Government Documents Department
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Relative importance of various sources of defect-producing hydrogen introduced into steel during application of vitreous coatings

Description: "When porcelain enamels or vitreous-type ceramic coatings are applied to ferrous metals, there is believed to be an evolution of hydrogen gas both during and after the firing operation. At elevated temperatures rapid evolution may result in blistering while if hydrogen becomes trapped in the steel during the rapid cooling following the firing operation gas pressures may be generated at the coating-metal interface and flakes of the coating literally blown off the metal. To determine experimental… more
Date: July 12, 1951
Creator: Moore, Dwight G.; Mason, Mary A. & Harrison, William N.
Partner: UNT Libraries Government Documents Department
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Effect on longitudinal stability and control characteristics of a Boeing B-29 airplane of variations in stick-force and control-rate characteristics obtained through use of a booster in the elevator-control system

Description: A longitudinal stability and control characteristics of a Boeing B-29 airplane have been measured with a booster incorporated in the elevator-control system. Tests were made to determine the effects on the handling qualities of the test airplane of variations in the pilot's control-force gradients as well as the effects of variations in the maximum rate of control motion supplied by the booster. The results of the control-rate investigation indicate that large airplanes may have satisfactory ha… more
Date: April 12, 1950
Creator: Mathews, Charles W.; Talmage, Donald B. & Whitten, James B.
Partner: UNT Libraries Government Documents Department
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Two-and Three-Dimensional Unsteady Lift Problems in High-Speed Flight

Description: "The problem of transient lift on two- and three-dimensional wings flying at high speeds is discussed as a boundary-value problem for the classical wave equation. Kirchoff's formula is applied so that the analysis is reduced, just as in the steady state, to an investigation of sources and doublets. The applications include the evaluation of indicial lift and pitching-moment curves for two-dimensional sinking and pitching wings flying at Mach numbers equal to 0, 0.8, 1.0, 1.2 and 2.0" (p. 393).
Date: October 12, 1950
Creator: Lomax, Harvard; Heaslet, Max A.; Fuller, Franklyn B. & Sluder, Loma
Partner: UNT Libraries Government Documents Department
open access

Analysis of Turbulent Free-Convection Boundary Layer on Flat Plate

Description: "With the use of Karman's integrated momentum equation for the boundary layer and data on the wall-shearing stress and heat transfer in forced-convection flow, a calculation was carried out for the flow and heat transfer in the turbulent free-convection boundary layer on a vertical flat plate. The calculation is for a fluid with a Prandtl number that is close to 1. A formula was derived for the heat-transfer coefficient that was in good agreement with experimental data in the range of Grashof n… more
Date: July 12, 1950
Creator: Eckert, E. R. G. & Jackson, Thomas W.
Partner: UNT Libraries Government Documents Department
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Analytical Derivation and Experimental Evaluation of Short-Bearing Approximation for Full Journal Bearing

Description: From Introduction: "This report extends the short-bearing pressure-distribution function of Michell and Cardullo to give equations for the various bearing characteristics. This short-bearing approximation makes available formulas relating eccentricity ratio to applied load, attitude angle, angular position of peak film pressure to unit pressure on projected area."
Date: June 12, 1953
Creator: DuBois, George B. & Ocvirk, Fred W.
Partner: UNT Libraries Government Documents Department
open access

Analysis and Prediction of Longitudinal Stability of Airplanes

Description: From Introduction: "The present report presents the results of such an analysis as regards the longitudinal-stability and control characteristics of the various airplanes tested."
Date: December 12, 1940
Creator: Gilruth, R. R. & White, M. D.
Partner: UNT Libraries Government Documents Department
open access

Wind-Tunnel Investigation of an NACA 23012 Airfoil with Various Arrangements of Slotted Flaps

Description: "An investigation was made in the 7 by 10-foot wind tunnel and in the variable-density wind tunnel of the NACA 23012 airfoil with various slotted-flap arrangements. The purpose of the investigation in the 7 by 10-foot wind tunnel was to determine the airfoil section aerodynamic characteristics as affected by flap shape, slot shape, and flap location. The flap position for maximum lift; polars for arrangements favorable for take-off and climb; and complete lift, drag, and pitching-moment charact… more
Date: February 12, 1938
Creator: Wenzinger, Carl J. & Harris, Thomas A.
Partner: UNT Libraries Government Documents Department
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Strength of Welded Aircraft Joints

Description: "This investigation is a continuation of work started in 1928 and described in NACA-TR-348 which shows that the insertion of gusset plates was the most satisfactory way of strengthening a joint. Additional tests of the present series show that joints of this type could be improved by cutting out the portion of the plate between the intersecting tubes. T and lattice joints in thin-walled tubing 1 1/2 by 0.020 inch have somewhat lower strengths than joints in tubing of greater wall thickness beca… more
Date: August 12, 1936
Creator: Brueggeman, W. C.
Partner: UNT Libraries Government Documents Department
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Wind-tunnel investigation of wings with ordinary ailerons and full-span external-airfoil flaps

Description: Report presents an investigation carried out in the NACA 7- by 10-foot wind tunnel of an NACA 23012 airfoil equipped, first, with a full-span NACA 23012 external-airfoil flap having a chord 0.20 of the main airfoil chord and with a full-span aileron with a chord 0.12 of the main airfoil chord on the trailing edge of the main airfoil and equipped second, with a 0.30-chord full-span NACA 23012 external-airfoil flap and a 0.13-chord full-span aileron. The results are arranged in three groups, the … more
Date: March 12, 1937
Creator: Platt, Robert C. & Shortal, Joseph A.
Partner: UNT Libraries Government Documents Department
open access

Tests of a Wing-Nacelle-Propeller Combination at Several Pitch Settings Up to 42 Degrees

Description: This report presents the results of tests of a 4-foot model of Navy propeller No. 4412 in conjunction with an NACA cowled nacelle mounted ahead of a thick wing in the 20-foot propeller-research tunnel. A range of propeller pitches from 17 degrees to 42 degrees at 0.75r was covered, and for this propeller the efficiency reached a maximum at a pitch setting of 27 degrees; at high pitches the efficiencies were slightly lower. The corrected propulsive efficiency is shown to be independent of the an… more
Date: November 12, 1935
Creator: Windler, Ray
Partner: UNT Libraries Government Documents Department
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Interference of Wing and Fuselage From Tests of 28 Combinations in the N.A.C.A. Variable-Density Tunnel

Description: Report presents the results of tests conducted on 28 wing-fuselage combinations made in the variable-density wind tunnel as a part of the wing-fuselage interference program being conducted therein and in addition to the 209 combinations previously reported in NACA-TR-540. These tests practically complete the study of combinations with a rectangular fuselage and continue the study of combinations with a round fuselage and a tapered wing.
Date: March 12, 1936
Creator: Sherman, Albert
Partner: UNT Libraries Government Documents Department
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A study of the two-control operation of an airplane

Description: The two-control operation of a conventional airplane is treated by means of the theory of disturbed motions. The consequences of this method of control are studied with regard to the stability of the airplane in its unconstrained components of motion and the movements set up during turn maneuvers.
Date: August 12, 1936
Creator: Jones, Robert T.
Partner: UNT Libraries Government Documents Department
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