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Investigation of Effects of Various Camouflage Paints and Painting Procedures on the Drag Characteristics of an NACA 65(Sub 421)-420, a = 1.0 Airfoil Section

Description: Bulletin presenting an investigation of the effects of various camouflage paints and painting procedures on the drag characteristics of a 60-inch-chord low-drag airfoil in the NACA two-dimensional low-turbulence pressure tunnel.
Date: July 1944
Creator: Braslow, Albert L.
Partner: UNT Libraries Government Documents Department

Measurements of the Drag and Pressure Distribution on a Body of Revolution Throughout Transition From Subsonic to Supersonic Speeds

Description: Memorandum presenting an investigation of the drag and pressure distribution on a body of revolution of fineness ratio 12 as measured by the free-fall method. Analysis of the results has provided knowledge of the mechanism of the abrupt drag rise which occurs near the speed of sound, and demonstrates that the theoretical method described in a previous report satisfactorily predicts the shape of the measured pressure distributions at low supersonic speeds.
Date: January 16, 1950
Creator: Thompson, Jim Rogers
Partner: UNT Libraries Government Documents Department

Axially Symmetric Shapes With Minimum Wave Drag

Description: Report presenting external wave drag of bodies of revolution moving at supersonic speeds, which can be expressed either in terms of the geometry of the body or in terms of the body-simulating axial source distribution. The second of the methods is found to be more tractable.
Date: February 1955
Creator: Heaslet, Max A. & Fuller, Franklyn B.
Partner: UNT Libraries Government Documents Department

The Drag of Finite-Length Cylinders Determined From Flight Tests at High Reynolds Numbers for a Mach Number Range From 0.5 to 1.3

Description: "Results of a free-flight investigation to determine the drag of circular, finite-length cylinders are presented for a Mach number range from about 0.5 to 1.3. Also included are drag results of previous experimental tests of infinite-length cylinders. Drag of circular cylinders at supersonic speeds is largely independent of fineness ratio and Reynolds number; whereas, at subsonic speeds, the drag of finite-length cylinders (fineness rations of about 60 and below) increases as their fineness ratios increase" (p. 1).
Date: June 1953
Creator: Welsh, Clement J.
Partner: UNT Libraries Government Documents Department

Drag Measurements on a Junkers Wing Section: Application of the Betz Method to the Results of Comparative Tests Made on a Model and on an Airplane in Flight

Description: The comparison of model tests in flight can be based on the result of such measurements. They are very important from the aerodynamical point of view, as they lead to useful conclusions regarding the behavior of the wing, its best shape and the conformity of theoretical and actual flow. Although there still remains a certain prejudice against such measurements, I have still attempted to make these comparative tests in order to inspire confidence in their reliability.
Date: September 1927
Creator: Weidinger, Hanns
Partner: UNT Libraries Government Documents Department

The Drag of Streamline Wires

Description: "Preliminary results are given of drag tests of streamline wires. Full-size wires were tested over a wide range of speeds in the N.A.C.A. high speed tunnel. The results are thus directly applicable to full-scale problems and include any compressibility effects encountered at the higher speeds. The results show how protuberances may be employed on conventional streamline wires to reduce the drag, and also show how the conventional wires compare with others having sections more like strut or symmetrical airfoil sections" (p. 1).
Date: December 1933
Creator: Jacobs, Eastman N.
Partner: UNT Libraries Government Documents Department

The Drag of Zeppelin Airships

Description: This report is a discussion of the results of tests with Zeppelin airships, in which the propellers were stopped as quickly as possible while the airship was in full flight. In this paper the author refers to the theory involved in these tests and calls attention to one scientifically interesting fact which can be derived from the tests and which has not yet been noted. The most important question concerning the tests is: does the negative acceleration of an airship with stopped propellers supply proper data for determining the drag of the airship when in uniform flight?
Date: 1923
Creator: Munk, Max M.
Partner: UNT Libraries Government Documents Department

Drag Tests of 4/9-Scale Model Engine Nacelles With Various Cowlings

Description: "Results are given of drag tests of 4/9-scale model radial air-cooled engine nacelles made as a part of a general investigation of wing-nacelle-propeller interference. A small nacelle of the type commonly used with exposed engine cylinders was tested with various forms of cowling over the cylinders. The effects of cowling-ring position and of angle of ring chord to the thrust line were investigated. An N.A.C.A. cowled nacelle and a smooth body were also tested. The results are given at 50, 75, and 100 miles per hour for -5 degrees, 0 degrees, 5 degrees, 10 degrees, 15 degrees angle of pitch" (p. 1).
Date: October 1932
Creator: Windler, Ray
Partner: UNT Libraries Government Documents Department

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

Description: 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.
Partner: UNT Libraries Government Documents Department

Free-Flight Investigation to Determine the Inlet External Drag of Four Inlet Models at Mach Numbers From 1.50 to 3.00

Description: Memorandum presenting a free-flight investigation conducted on four supersonic nose inlets. Each inlet used conical-shock and isentropic-compression center bodies; two of the models had internal contraction and two did not. Results regarding drag coefficient, pressure recovery, mass-flow ratio, and Reynolds number range are provided.
Date: April 21, 1958
Creator: Kouyoumjian, Walter L.
Partner: UNT Libraries Government Documents Department

A Flight Investigation of the Effect of Surface Roughness on Wing Profile Drag With Transition Fixed

Description: Report presenting a flight investigation made on a wing section of a P-47D airplane to determine the effect of roughness on wing profile drag with transition fixed far forward. Surveys of the wake were made for two surface conditions with transition fixed by a thread at 5 percent chord back of the leading edge on the upper and lower surfaces. Below the Mach number at which shock occurred, variations in Mach number of as much as 0.16 appeared to have no appreciable effect on the section profile-drag coefficients of either the smooth or roughened surfaces with transition fixed.
Date: September 1944
Creator: Zalovcik, John A. & Wood, Clotaire
Partner: UNT Libraries Government Documents Department

Effect of Camber on the Drag of a Body of Revolution

Description: Memorandum presenting an investigation to determine the effect of camber on the drag of a body of revolution. The drag of a straight body of revolution was measured and compared with that of a body that differed only in that its center line was cambered in the form of a parabola. The addition of a small amount of camber was found to cause very little increase in the minimum foredrag of the model tested.
Date: October 19, 1956
Creator: Dickey, Robert R.
Partner: UNT Libraries Government Documents Department

A Note on the Drag Due to Lift of Rectangular Wings of Low Aspect Ratio

Description: Note presenting some methods of estimating the induced drag of low-aspect-ratio wings, which are discussed and compared with experiments. The profile drag due to lift is also discussed and a method is developed which relates the effect of aspect ratio on the profile drag due to lift to an "effective" two-dimensional lift coefficient.
Date: January 1955
Creator: Polhamus, Edward C.
Partner: UNT Libraries Government Documents Department

Estimation of Inlet Lip Forces at Subsonic and Supersonic Speeds

Description: "The effects of lip thickness on inlet performance are estimated as functions of mass flow for subsonic and supersonic flight speeds. At subsonic speeds, pressure-recovery losses and additive drag are shown to decrease linearly with increasing lip frontal area if the maximum suction force is attained. At supersonic speeds, inlet drag increases linearly with inlet lip frontal area at full mass flow. For reduced mass flow, some reduction in additive drag is possible with lips of moderate thickness, but the magnitude of this reduction becomes negligible as flight speed increases" (p. 1).
Date: June 1955
Creator: Moeckel, W. E.
Partner: UNT Libraries Government Documents Department

Determination of the Lift and Drag Characteristics of an Airplane in Flight

Description: Flight tests to determine lift and drag characteristics are discussed. A review is given of the fundamental principles on which the tests are based and on the forces acting on an airplane in the various conditions of steady flight. Glide with and without propeller thrust and the relation between angle of attack and the indicated airspeed for different conditions of steady flight are discussed. The glide test procedure and the problem of the propeller are discussed.
Date: August 1925
Creator: Green, Maurice W.
Partner: UNT Libraries Government Documents Department

Free-Flight Investigation at Mach Numbers From 0.8 to 1.5 of the Effect of a Fuselage Indentation on the Zero-Lift Drag of a 52.5 Degree Sweptback-Wing-Body Configuration With Symmetrically Mounted Stores on the Fuselage

Description: Memorandum presenting two rocket-propelled models flight tested at Mach numbers from 0.8 to 1.5 to determine the effect of a fuselage indentation on the drag of a 52.5 degree sweptback-wing-body configuration with two large strut-mounted store symmetrically located above and below the fuselage. The fuselage had a symmetrical, Mach number 1.0 indentation designed to cancel the wing area normal to the plane of symmetry. Results regarding total drag and pressure drag are provided.
Date: February 20, 1958
Creator: Hoffman, Sherwood
Partner: UNT Libraries Government Documents Department

Altitude-Wind-Tunnel Investigation of a 3000-Pound-Thrust Axial-Flow Turbojet Engine, Part 5, Performance and Windmilling Drag Characteristics

Description: "An investigation has been conducted in the NACA Cleveland altitude wind tunnel to evaluate the performance and windmilling drag characteristics of an original and a modified turbojet engine of the same type. Data have been obtained at simulated altitudes from 5000 to 45,000 feet, simulated flight Mach numbers from 0.09 to 1.08, and engine speeds from 4000 to 12,500 rpm. Engine performance data are presented for both engines to show the effects of altitude at a flight Mach number of 0.25 and of flight Mach number at an altitude of 25,000 feet" (p. 1).
Date: August 23, 1948
Creator: Meyer, Carl L. & Bloomer, Harry E.
Partner: UNT Libraries Government Documents Department

Performance of air inlets at transonic and low supersonic speeds

Description: A general discussion of the air-inlet problem is presented. Recently obtained drag and pressure-recovery data for transonic-type nose, scoop, and wing-root inlets are summarized. Preliminary results concerning the performance of the sharp-edged supersonic-type inlets at transonic and subsonic speeds also are given.
Date: February 16, 1952
Creator: Nichols, Mark R. & Pendley, Robert E.
Partner: UNT Libraries Government Documents Department

Theory of wing-body drag at supersonic speeds

Description: "The relation of Whitcomb's "area rule" to the linear formulas for wave drag at lightly supersonic speeds is discussed. By adopting an approximate relation between the source strength and the geometry of a wing-body combination, the wave-drag theory is expressed in terms involving the areas intercepted by oblique planes or Mach planes. The resulting formulas are checked by comparison with the drag measurements obtained in wind-tunnel experiments and in experiments with falling models in free air. Finally, a theory for determining wing-body shapes of minimum drag at supersonic Mach numbers is discussed and some preliminary experiments are reported" (p. 757).
Date: July 8, 1953
Creator: Jones, Robert T.
Partner: UNT Libraries Government Documents Department

Point drag and total drag of navy struts no. 1 modified

Description: This report deals with the results of tests on struts conducted at Washington Navy Yard. Two models of the modified Navy strut, no. 1, were tested in the 8 by 8 foot wind tunnel. The tests were made to determine the total resistance end effect and the pressure distribution at various wind-tunnel speeds with the length of the strut transverse to the current. Only the measurements made at zero pitch and yaw are given in this report.
Date: 1923
Creator: Zahm, A. F.; Smith, R. H. & Hill, G. C.
Partner: UNT Libraries Government Documents Department

An experimental study of the zero-angle-of attack transonic drag associated with the vertical position of a horizontal tail at zero incidence

Description: Report presenting a study of the transonic drag associated with varying the vertical location of the horizontal tail of a representative tail-body combination. Factors which significantly influenced the results were flow separation in the horizontal tail-body juncture, afterbody-tail-interference pressure drag, and a downwash over the horizontal tail which resulted from the boundary conditions of the converging afterbody.
Date: October 25, 1956
Creator: Howell, Robert R.
Partner: UNT Libraries Government Documents Department

Method for the determination of the spanwise lift distribution

Description: The method for determination of the spanwise lift distribution is based on the Fourier series for the representation of the lift distribution. The lift distribution, as well as the angle of attack, is split up in four elementary distributions. The insertion of the angle-of-attack distribution in the Fourier series for the lift distribution gives a compound third series which is of particular advantage for the determination of the lift distribution. The method is illustrated in an example and supplemented by a graphical method. Lastly, the results of several comparative calculations with other methods are reported.
Date: October 1935
Creator: Lippisch, A.
Partner: UNT Libraries Government Documents Department