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Pressure Pulsations on Rigid Airfoils at Transonic Speeds

Description: Report presenting testing to obtain the effects of changes in Mach number, thickness ratio, and angle of attack on the amplitude of the pressure pulsations on several airfoils at transonic speeds. The tests were performed on NACA 65A-series airfoils with thicknesses ranging from 4 to 12 percent chord at a range of Mach numbers and angles of attack. The relations of pressure pulsations to buffeting are also provided.
Date: December 6, 1951
Creator: Humphreys, Milton D.
Partner: UNT Libraries Government Documents Department

Some Effects of Spanwise Aileron Location and Wing Structural Rigidity on the Rolling Effectiveness of 0.3-Chord Flap-Type Ailerons on a Tapered Wing Having 63 Degrees Sweepback at the Leading Edge and Naca 64A005 Airfoil Sections

Description: Report presenting an investigation of some effects of aileron spanwise location and wing structural rigidity on the rolling power of 0.3-chord plain, flap-type ailerons on a wing with a taper ratio of 0.25, an aspect ratio of 3.5, and swept back 63 degrees at the leading edge. Results regarding the aeroelastic effects and aileron span and spanwise location are provided.
Date: June 22, 1951
Creator: Strass, H. Kurt; Fields, E. M. & Schult, Eugene D.
Partner: UNT Libraries Government Documents Department

The Use of Two-Dimensional Section Data to Estimate the Low-Speed Wing Lift Coefficient at Which Section Stall First Appears on a Swept Wing

Description: Report discusses a procedure for estimating the wing lift coefficient for and spanwise location of the first occurrence of section stall on a swept wing. It has been modified from a method used to calculate the same information for unswept wings. The effects of split flaps, leading-edge modifications, and fences are described.
Date: July 27, 1951
Creator: Maki, Ralph L.
Partner: UNT Libraries Government Documents Department

Dynamic Stability and Control Characteristics of a Delta-Wing Vertically Rising Airplane Model in Take-Offs, Landings, and Hovering Flight

Description: Report presenting an investigation by means of tests of a flying model in still air to determine the dynamic stability and control characteristics of a delta-wing vertically rising airplane in take-off, landing, and hovering phases of flight. The uncontrolled pitching motion consisted of an unstable oscillation which was more unstable with a rearward than with the normal center-of-gravity location.
Date: October 9, 1951
Creator: Lovell, Powell M., Jr.; Bates, William R. & Smith, Charles C., Jr.
Partner: UNT Libraries Government Documents Department

A Wind-Tunnel Investigation of the Static Stability Characteristics of a 1/8-Scale Ejectable Pilot-Seat Combination at a Mach Number of 0.8

Description: Report presenting an investigation of a model of an ejectable pilot seat combination with and without stabilizing fins. The main purpose of the investigation was to determine the static aerodynamic characteristics and effectiveness of various stabilizing fins at a high subsonic Mach number. Results regarding stability and force characteristics for the combinations are provided.
Date: December 7, 1951
Creator: Visconti, Fioravante & Nuber, Robert J.
Partner: UNT Libraries Government Documents Department

Comparison of Measured Efficiencies of Nine Turbine Designs with Efficiencies Predicted by Two Empirical Methods

Description: Empirical methods of Ainley and Kochendorfer and Nettles were used to predict performances of nine turbine designs. Measured and predicted performances were compared. Appropriate values of blade-loss parameter were determined for the method of Kochendorfer and Nettles. The measured design-point efficiencies were lower than predicted by as much as 0.09 (Ainley and 0.07 (Kochendorfer and Nettles).
Date: August 20, 1951
Creator: English, Robert E. & Cavicchi, Richard H.
Partner: UNT Libraries Government Documents Department

Effective Modulus in Plastic Buckling of High-Strength Aluminum-Alloy Sheet

Description: Memorandum presenting results of compressive tests on duplicate longitudinal specimens from sheets of 76S-T6 and R301-T aluminum alloys in three thicknesses as graphs of tangent modulus, secant modulus, and are plotted against stress on a dimensionless basis.
Date: September 20, 1951
Creator: Miller, James A. & Jacobs, Pearl V.
Partner: UNT Libraries Government Documents Department

Arrangement of Bodies of Revolution in Supersonic Flow to Reduce Wave Drag

Description: "The wave drag of a combination of slender bodies of revolution at zero angle of attack is studied with a view to determining the arrangements for which the total drag is a minimum. Linearized theory is used to calculate the pressure distribution in the field surrounding the bodies. The interference drag coefficient is computed for different arrangements" (p. 1).
Date: December 17, 1951
Creator: Friedman, Morris D.
Partner: UNT Libraries Government Documents Department

Properties of Low-Carbon N-155 Alloy Bar Stock From 1200 to 1800 Degrees Fahrenheit

Description: Memorandum presenting the results of an investigation to establish rupture and total-deformation strengths at 1200 and 1800 degrees Fahrenheit for typical commercial treatments of low-carbon N-155 alloy. The results show that there were large differences in strength between the heats of bar stock at temperatures above 1200 degrees Fahrenheit except when a 2200 degree Fahrenheit solution treatment was used.
Date: May 3, 1951
Creator: Freeman, J. W. & White, A. E.
Partner: UNT Libraries Government Documents Department

Experimental Investigation of Effect of Jet Exit Configuration on Thrust and Drag

Description: Memorandum presenting an investigation of the problem of performance losses occurring when airplanes equipped with afterburner and cooling-air ejector installations are flown with the afterburner inoperative. Two sources of the performance losses occurring under some operation conditions were identified: an overexpansion of the propulsive jet and an internal shock system and the excessive pumping action resulting from the off-design.
Date: December 20, 1951
Creator: Callaghan, Edmund E. & Coles, Willard D.
Partner: UNT Libraries Government Documents Department

Altitude Wind Tunnel Investigation of the Performance of Compressor, Combustor, and Turbine Components of Prototype J47D (RX1-1) Turbojet Engine

Description: "As a portion of an over-all performance investigation of the prototype J47D (RX-1) turbojet engine, performance of the compressor, combustor, and turbine components has been determined in the Lewis altitude wind tunnel over a range of altitude from 5000 to 55,000 feet and at flight Mach numbers from 0.19 to 0.92. Investigations were conducted with the engine operating on an electronic control schedule and slow with a two-lever control system by which fuel flow and exhaust-nozzle area could be controlled separately. Two combustor configurations were investigated" (p. 1).
Date: December 21, 1951
Creator: Farley, John M.
Partner: UNT Libraries Government Documents Department

Low-Speed Characteristics of a 45 Degree Swept Wing with Leading-Edge Inlets

Description: Memorandum presenting an investigation to determine the low-speed aerodynamic characteristics of a 45 degree swept wing with leading-edge inlets. The wing had a constant chord and completely spanned the wind tunnel. Results regarding surface-pressure characteristics, lift and pitching-moment characteristics, wake-drag characteristics, and internal-flow characteristics are provided.
Date: August 13, 1951
Creator: Dannenberg, Robert E.
Partner: UNT Libraries Government Documents Department

The Effect of Raking the Aileron Tips on the Lateral-Control and Hinge-Moment Characteristics of a 20-Percent-Chord Partial-Span Outboard Aileron on a Wing With Leading-Edge Swept Back 51.3 Degrees

Description: Report presenting an investigation at low speed to determine the lateral-control and hinge-moment characteristics of a 20-percent-chord unsealed partial-span outboard aileron with several plan forms. Results regarding the wing aerodynamic characteristics are also provided.
Date: November 26, 1951
Creator: Hammond, Alexander D.
Partner: UNT Libraries Government Documents Department

Elevated Temperature Properties of Titanium Carbide Base Ceramals Containing Nickel or Iron

Description: Elevated-temperature properties of titanium carbide base ceramals containing nickel or iron were determined in oxidation, modulus of rupture, tensile strength, and thermal-shock resistance. These materials followed the general growth law and exhibited two stages in oxidation. The following tensile strengths were found at 2000 degrees F: 13.3 weight percent nickel, 16, 150 pounds per square inch; 11.8 weight percent iron, 12,500 pounds per square inch; unalloyed titanium carbide, 16,450 pounds per square inch. Nickel or iron additions to titanium carbide improved the thermal-shock resistance, nickel more. The path of fracture in tensile and thermal-shock specimens was found to progress approximately 50 percent intergranularly and 50 percent transgranularly.
Date: December 3, 1951
Creator: Cooper, A. L. & Colteryahn, L. E.
Partner: UNT Libraries Government Documents Department

Effects of Propeller-Shank Geometry and Propeller-Spinner-Juncture Configuration on Characteristics of an NACA 1-Series Cowling-Spinner Combination With an Eight-Blade Dual-Rotation Propeller

Description: Report presenting an investigation at low speed in the low-turbulence tunnel to determine the effects of variations in propeller-shank geometry and propeller-spinner-juncture configuration on the aerodynamic characteristics of an NACA 1-series cowling-spinner combination with an eight-blade dual-rotation propeller. Results regarding internal flow and external flow are provided.
Date: September 25, 1951
Creator: Keith, Arvid L., Jr.; Bingham, Gene J. & Rubin, Arnold J.
Partner: UNT Libraries Government Documents Department

Effect of Section Thickness and Trailing-Edge Radius on the Performance of NACA 65-Series Compressor Blades in Cascade at Low Speeds

Description: Report presenting tests of NACA 65-series compressor blades cambered to an isolated airfoil lift coefficient of 1.2 at several maximum section thicknesses to obtain the effect of maximum section thickness on section operating characteristics. Information about surface pressure trends, design angle-of-attack selection, drag, operating range, and critical Mach number is also provided. Changing the section thickness was not found to significantly affect the design angle of attack selected.
Date: December 13, 1951
Creator: Herrig, L. Joseph; Emery, James C. & Erwin, John R.
Partner: UNT Libraries Government Documents Department

Effect of the Proximity of the Ground on the Stability and Control Characteristics of a Vertically Rising Airplane Model in the Hovering Condition

Description: Report discussing the effect of the proximity of the ground on the stability and control characteristics of a vertically rising airplane model in the hovering condition. The dynamic behavior of the model in take-offs and landings and when it was hovering near the ground was also investigated. Force tests to determine the change in the vertical-tail yawing moments with control deflection and with angle of yaw for various heights were also conducted.
Date: September 19, 1951
Creator: Smith, Charles C., Jr.; Lovell, Powell M., Jr. & Bates, William R.
Partner: UNT Libraries Government Documents Department

Effect of Formation Position on Load Factors Obtained on F2H Airplanes

Description: Report presenting results of a four-plane formation flight with twelve pull-up maneuvers in the form of plots of maximum load factor attained versus airplane position for three combinations of four F2H airplanes. The load factor was generally found to increase toward the end of the formation, and movements of the lead plane that are too sharp might cause excessive loads on the last plane in the formation.
Date: December 7, 1951
Creator: Huss, Carl R. & Hamer, Harold A.
Partner: UNT Libraries Government Documents Department

Determination and Use of the Local Recovery Factor for Calculating the Effectiveness Gas Temperature for Turbine Blades

Description: In an experimental investigation of local recovery factors for a blade having a pressure distribution similar to that of a typical reaction-type turbine blade, it a was found that the recovery factors were essentially independent of Mach number, Reynolds number, pressure gradient, and position on the blade surface except for regions where the boundary layer was probably in the transition range from laminar to turbulent. The recommended value of local subsonic recovery factor for use in calculating the effective gas temperature for gas turbine blades was 0.89.
Date: September 24, 1951
Creator: Esgar, Jack B. & Lea, Alfred L.
Partner: UNT Libraries Government Documents Department

Comparison of High-Speed Operating Characteristics of Size 215 Cylindrical-Roller Bearings as Determined in Turbojet Engine and in Laboratory Test Rig

Description: "A comparison of the operating characteristics of 75-millimeter-bore (size 215) cylindrical-roller one-piece inner-race-riding cage-type bearings was made using a laboratory test rig and a turbojet engine. Cooling correlation parameters were determined by means of dimensional analysis, and the generalized results for both the inner- and outer-race bearing operating temperatures are compared for the laboratory test rig and the turbojet engine. Inner- and outer-race cooling-correlation curves were obtained for the turbojet-engine turbine-roller bearing with the same inner- and outer-race correlation parameters and exponents as those determined for the laboratory test-rig bearing" (p. 1).
Date: November 28, 1951
Creator: Macks, E. Fred & Nemeth, Zolton N.
Partner: UNT Libraries Government Documents Department

Comparison of Semispan and Full-Span Tests of a 47.5 Degrees Sweptback Wing With Symmetrical Circular-Arc Sections and Having Drooped-Nose Flaps, Trailing-Edge Flaps, and Ailerons

Description: Report presenting an investigation to compare the characteristics of a full-span and a semispan highly swept wing in order to evaluate the general validity of the semispan wing testing technique. Results regarding the lift, drag, and pitching-moment characteristics are provided.
Date: December 5, 1951
Creator: Lipson, Stanley & Barnett, U. Reed, Jr.
Partner: UNT Libraries Government Documents Department

Derivation of the Equations of Motion of a Symmetrical Wing-Tip-Coupled Airplane Configuration With Rotational Freedom at the Junctures

Description: "The method of Lagrange multipliers is used to take account of the dynamic effects of the constraints at the wing tips when two identical airplanes are coupled to the wing tips of a "mother" airplane. The resulting equations of motion of this symmetrical configuration are derived for one, two, or three degrees of rotational freedom at each joint" (p. 1).
Date: October 8, 1951
Creator: Schy, Albert A.
Partner: UNT Libraries Government Documents Department

Characteristics of a Wedge With Various Holder Configurations for Static-Pressure Measurements in Subsonic Gas Streams

Description: The characteristics of a wedge static-pressure sensing element with various holder configurations were determined and compared with the characteristics of the conventional tube. The probes were tested over a range of Mach number from 0.3 to 0.95 and at various pitch and yaw angles. The investigation showed that the spike-mounted wedge sensing element has a pressure coefficient comparable with the conventional subsonic static-pressure probe and the pressure coefficient of the wedge varied less than that of the conventional probe for corresponding change of yaw angle.
Date: September 5, 1951
Creator: Gettelman, Clarence C. & Krause, Lloyd N.
Partner: UNT Libraries Government Documents Department