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Investigation of translating-double-cone axisymmetric inlets with cowl projected areas 40 and 20 percent of maximum at Mach numbers from 3.0 to 2.0

Description: Report presenting the performance of two translating-double-cone inlets with contrasting rates of turning on the spike shoulder and corresponding cowl projected frontal areas of 40 and 20 percent of maximum compared over a range of Mach numbers. Results regarding internal-flow performance, external-flow performance, inlet airflow patterns, and propulsive-thrust comparison are provided.
Date: May 20, 1957
Creator: Connors, James F.; Wise, George A. & Lovell, J. Calvin
Partner: UNT Libraries Government Documents Department

Investigation of vertical drag and periodic airloads acting on flat panels in a rotor slipstream

Description: Tests have been conducted on the Langley helicopter test tower to determine the vertical drag and pressure distributions on flat panels mounted below a helicopter rotor. Calculations of the vertical drag by use of a strip-analysis procedure outlined in the paper and the assumption of a fully contracted wake agreed well with the experimental results over the range from 0.2 to 0.64 rotor radius beneath the plane of zero flapping. The pressure increase caused by the passage of the blade over the panel is a maximum at about the 0.8 radius spanwise station. At this station, the pressure decreases from 10 times the disk loading per blade at 0.05 radius beneath the rotor plane of zero flapping to one-half of the disk loading per blade at 0.64 radius beneath the plane of zero flapping.
Date: December 1956
Creator: Makofski, Robert A. & Menkick, George F.
Partner: UNT Libraries Government Documents Department

Measurements of the effects of thickness ratio and aspect ratio on the drag of rectangular-plan-form airfoils at transonic speeds

Description: Report presenting testing conducted on two airfoils from a series of rectangular-plan-form airfoils of aspect ratios 7.6 and 5.1 and with NACA 65-006, 65-009, and 65-012 sections using the free-fall method. Results regarding the time histories, ground-velocity data, airfoil drag measurements, and drag coefficients are provided.
Date: June 20, 1947
Creator: Thompson, Jim Rogers & Mathews, Charles W.
Partner: UNT Libraries Government Documents Department

Effect on Drag of Longitudinal Positioning of Half-Submerged and Pylon-Mounted Douglas Aircraft Stores on a Fuselage with and without Cavities between Mach Numbers 0.9 and 1.8

Description: From Summary: "The effect on drag of positioning symmetrically mounted Douglas Aircraft Company, Inc. stores in pairs on a parabolic fuselage of fineness ratio 10.0 has been determined by flight tests of rocket-propelled, zero-lift models through a range of Mach number from 0.9 to 1.8. The stores were mounted in half-submerged positions and on pylons and were tested in three longitudinal locations on the fuselage with the forward position being located at the maximum diameter of the fuselage. The effects on drag of removing the half-submerged stores or extending them outward on pylons also was investigated by tests of models with half-submerged-store cavities on the fuselage. Two pylons differing in airfoil section and thickness were tested at the forward position of the stores on the fuselage with cavities."
Date: July 15, 1954
Creator: Hoffman, Sherwood & Wolff, Austin L.
Partner: UNT Libraries Government Documents Department

Low-lift drag and stability data from rocket models of a modified-delta-wing airplane with and without external stores at Mach numbers from 0.8 to 1.36

Description: Report presenting a flight investigation to determine the drag and stability at low lift coefficients of models of a modified-delta-wing airplane at a range of Mach and Reynolds numbers. A summary of the drag and stability data from the tests is provided.
Date: March 26, 1953
Creator: Mitcham, Grady L. & Blanchard, Willard S., Jr.
Partner: UNT Libraries Government Documents Department

The effect of nacelle combinations and size on the zero-lift drag of a 45 degree sweptback wing and body configuration as determined by free-flight tests at Mach numbers between 0.8 and 1.3

Description: Investigation of the effect on zero-lift drag of varying the size and number of symmetrically mounted nacelles on a 45 degree sweptback wing and body combination as determined by free-flight tests of rocket-propelled models over a range of Mach and Reynolds numbers. The nacelle configuration consisted of a twin-engine nacelle near the fuselage, a combination of single-engine nacelles at the wing tip and fuselage, a large nacelle at the wing tip, and a large nacelle near the fuselage.
Date: June 22, 1953
Creator: Hoffman, Sherwood & Pepper, William B., Jr.
Partner: UNT Libraries Government Documents Department

Drag of conical and circular-arc boattail afterbodies at Mach numbers from 0.6 to 1.3

Description: From Summary: "Drag characteristics of a series of related conical and circular-arc afterbodies are presented for Mach numbers from 0.6 to 1.3. Drag was obtained from pressure measurements on the boattail and solid base. The boattail angles tested ranged from 0 degrees to 45 degrees for ratios of base diameter to maximum body diameter ranging from 0 to 1.0."
Date: January 22, 1957
Creator: Silhan, Frank V. & Cubbage, James M., Jr.
Partner: UNT Libraries Government Documents Department

Comparative drag measurements at transonic speeds of rectangular sweptback NACA 65-009 airfoils mounted on a freely falling body

Description: From Summary: "Directly comparable drag measurements have been made of an airfoil with a conventional rectangular plan form and an airfoil with a sweptback plan form mounted on freely falling bodies. Both airfoils had NACA 65-009 sections and were identical in span, frontal area, and chord perpendicular to the leading edge. The sweptback plan form incorporated a sweepback angle of 45 degrees. The data obtained have been used to establish the relation between the airfoil drag coefficients and the free-stream Mach number over a range of Mach numbers from 0.90 to 1.27. The results of the measurements indicate that the drag of the sweptback plan form is less than 0.3 that of the rectangular plan form at a Mach number of 1.00 and is less than 0.4 that at a Mach number of 1.20."
Date: August 9, 1945
Creator: Mathews, Charles W. & Thompson, Jim Rogers
Partner: UNT Libraries Government Documents Department

Effect of wing sweep, taper, and thickness ratio on the transonic drag characteristics of wing-body combinations

Description: Report presenting the transonic drag characteristics of a series of wing-body combinations and their component parts using the free-fall method. The configurations examined had wings of various sweeps and thickness ratios mounted on identical bodies of fineness ratio 12.
Date: December 31, 1948
Creator: Thompson, Jim Rogers & Mathews, Charles W.
Partner: UNT Libraries Government Documents Department

Drag Measurements at Transonic Speeds of NACA 65-009 Airfoils Mounted on a Freely Falling Body to Determine the Effects of Sweepback and Aspect Ratio

Description: From Summary: "Drag measurements at transonic speeds on rectangular airfoils and on airfoils swept back 450 are reported. These airfoils, which were mounted on cylindrical test bodies, are part of a series being tested in free drops from high altitude to determine the effect of variation of basic airfoil parameters on airfoil drag characteristics at transonic speeds. These rectangular and swept-back airfoils had the same span, airfoil section (NACA 65-009), and chord perpendicular to the leading edge. The tests were made to compare the drag of rectangular and sweptback airfoils at a higher aspect ratio than had been used in a similar comparison reported previously."
Date: January 22, 1947
Creator: Mathews, Charles W. & Thompson, Jim Rogers
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

Investigation of symmetric body indentations designed to reduce the transonic zero-lift wave drag of a 45 degree swept wing with an NACA 64A006 section and with a thickened leading-edge section

Description: Report presenting a wind-tunnel investigation at Reynolds numbers of about 7,000,000 based on the mean aerodynamic chord of the wing and over a range of Mach numbers. Two airfoils were tested to evaluate the effect of a large leading-edge radius with increased thickness over the forward 40 percent of the chord on the reliability of the predictions of the supersonic area rule. Results regarding the comparison of basic- and modified-wing models, comparison of experimental and computed drag coefficients, and a comparison of indentations are provided.
Date: March 19, 1957
Creator: Holdaway, George H. & Hatfield, Elaine W.
Partner: UNT Libraries Government Documents Department

A summary of drag results from recent Langley full scale tunnel tests of Army and Navy airplanes

Description: Report presenting the results of a drag investigation of twelve military airplanes in order to increase their speed. The main purpose of the report is to point out undesirable aerodynamic features as a guide to airplane designers. Results regarding the power-plant installation, installations in wings, empennages, armament, canopies, and radio antenna are provided.
Date: February 1945
Creator: Lange, Roy H.
Partner: UNT Libraries Government Documents Department

Correlation of the drag characteristics of a typical pursuit airplane obtained from high-speed wind-tunnel and flight tests

Description: In order to obtain a correlation of drag data from wind-tunnel and flight tests at high Mach numbers, a typical pursuit airplane, with the propeller removed, was tested in flight at Mach numbers up to 0.755, and the results were compared with wind-tunnel tests of a 1/3-scale model of the airplane. The tests results show that the drag characteristics of the test airplane can be predicted with satisfactory accuracy from tests in the Ames 16-foot high-speed wind tunnel of the Ames Aeronautical Laboratory at both high and low Mach numbers. It is considered that this result is not unique with the airplane.
Date: November 2, 1944
Creator: Nissen, James M.; Gadeberg, Burnett L. & Hamilton, William T.
Partner: UNT Libraries Government Documents Department

Interference effects and drag of struts on a monoplane wing

Description: "Tests were conducted in the Variable Density Wind Tunnel of the NACA to determine the importance of the interference effects and drag of struts on a monoplane. Inclined struts were placed upon a Gottingen 387 airfoil in the lower surface positions and in two upper surface positions. Tests were made at values of Reynolds Number comparable with those obtained in flight. It was found that the interference drag of struts may be as great as the drag of the struts alone" (p. 1).
Date: February 1931
Creator: Ward, Kenneth E.
Partner: UNT Libraries Government Documents Department

Investigation of an Underslung Normal-Wedge Inlet at Free-Stream Mach Numbers From 1.50 to 1.99

Description: Two normal -wedge-inlet configurations (straight and sweptback splitter plates) were investigated in the Lewis 8- by 6-foot supersonic wind tunnel at Mach numbers of 1.50 to 1.99. Negligible differences occurred in the performances of the two normal-wedge inlets. In comparison with a previously tested scoop inlet, the normal-wedge configuration showed superior thrust-minus-drag characteristics at Mach 1.99. However the scoop inlet was better at Mach numbers of 1.80 and 1.50.
Date: March 19, 1957
Creator: Vargo, Donald J. & Weinstein, Maynard I.
Partner: UNT Libraries Government Documents Department