National Advisory Committee for Aeronautics (NACA) - 41 Matching Results

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Investigations on the Incompletely Developed Plane Diagonal-Tension Field

Description: This report presents the results of an investigation on the incompletely developed diagonal-tension field. Actual diagonal-tension beams work in an intermediate stage between pure shear and pure diagonal tension; the theory developed by Wagner for diagonal tension is not directly applicable.
Date: March 28, 1940
Creator: Kuhn, Paul
Partner: UNT Libraries Government Documents Department

Pressure distribution over NACA 23012 airfoil with a slotted and a split flap

Description: A pressure-distribution investigation has been conducted in the NACA 4 by 6-foot vertical wind tunnel to determine the air loads on an NACA 23012 airfoil in combination with a 25.66-percent-chord slotted flap and a 20-percent-chord split flap. Pressures were measured on both the upper and the lower surfaces of the main airfoil and the flaps for several angles of attack and at several flap settings. The data, presented as pressure diagrams and as graphs of the section coefficients for the flap alone and for the airfoil-flap combinations, are applicable to rib and flap design for a combination of a thick airfoil and a slotted or a split flap. The results of previous tests of a NACA 23012 airfoil with a slotted flap are compared with the present results.
Date: May 28, 1940
Creator: Harris, Thomas A. & Lowry, John G.
Partner: UNT Libraries Government Documents Department

Investigation of the Characteristics of a High-Aspect-Ratio Wing in the Langley 8-Foot High-Speed Tunnel

Description: "An investigation of the characteristics of a wing with an aspect ratio of 9.0 and an NACA 65-210 airfoil section has been made at Mach number up to 0.925. The wing tested has a taper ratio of 2.5:1.0, no twist, dihedral, or sweepback, and 20-percent - chord 37.5-percent-semispan plain ailerons. The results showed that serious changes in the normal-force characteristics occurred when the Mach number was increased above 0.74 at angles of attack between 4 deg. and 10 deg. and above 0.80 at 0 deg. angle of attack" (p. 1).
Date: August 28, 1940
Creator: Whitcomb, Richard T.
Partner: UNT Libraries Government Documents Department

An analysis of life expectancy of airplane wings in normal cruising flight

Description: From Summary: "In order to provide a basis for judging the relative importance of wing failure by fatigue and by single intense gusts, an analysis of wing life for normal cruising flight was made based on data on the frequency of atmospheric gusts. The independent variables considered in the analysis included stress-concentration factor, stress-load relation, wing loading, design and cruising speeds, design gust velocity, and airplane size. Several methods for estimating fatigue life from gust frequencies are discussed."
Date: May 28, 1945
Creator: Putnam, Abbott A.
Partner: UNT Libraries Government Documents Department

Investigation of Dive Brakes and a Dive-Recovery Flap on a High-Aspect-Ratio Wing in the Langley 8-Foot High-Speed Tunnel

Description: The results of tests made to determine the aerodynamic characteristics of a solid brake, a slotted brake, and a dive-recovery flap mounted on a high aspect ratio wing at high Mach numbers are presented. The data were obtained in the Langley 8-foot high-speed tunnel for corrected Mach numbers up to 0.940. The results have been analyzed with regard to the suitability of dive-control devices for a proposed high-speed airplane in limiting the airplane terminal Mach number by the use of dive brakes and in achieving favorable dive-recovery characteristics by the use of a dive-recovery flap. The analysis of the results indicated that the slotted brake would limit the proposed airplane terminal Mach number to values below 0.880 for altitudes up to 35,000 feet and a wing loading of 80 pounds per square foot and the dive-recovery flap would produce trim changes required for controlled pull-outs at 25,000 feet for a Mach number range from 0.800 to 0.900. Basic changes in spanwise loading are presented to aid in the evaluation of the wing strength requirements.
Date: August 28, 1946
Creator: Mattson, Axel T.
Partner: UNT Libraries Government Documents Department

Investigations of Effects of Surface Temperature and Single Roughness Elements on Boundary-Layer Transition

Description: "The laminar boundary layer and the position of the transition point were investigated on a heated flat plate. It was found that the Reynolds number of transition decreased as the temperature of the plate is increased. It is shown from simple qualitative analytical considerations that the effect of variable viscosity in the boundary layer due to the temperature difference produces a velocity profile with an inflection point if the wall temperature is higher than the free-stream temperature" (p. 587).
Date: August 28, 1946
Creator: Liepmann, Hans W. & Fila, Gertrude H.
Partner: UNT Libraries Government Documents Department

Investigation of the performance of a 20-inch ram jet using preheated fuel

Description: Report presenting the performance characteristics of a 20-inch ramjet opeerating with preheated unleaded 62 octane fuel. The results of the investigation indicated an improvement in the combustion efficiency and operating range of the ramjet when using preheated fuel.
Date: October 28, 1946
Creator: Perchonok, Eugene; Wilcox, Fred A. & Sterbentz, William H.
Partner: UNT Libraries Government Documents Department

An Analysis of the Full-Floating Journal Bearing

Description: An analysis of the operating characteristics of a full-floating bearing - a bearing in which a floating sleeve is located between the journal and bearing surfaces - is presented together with charts - from which the performance of such bearings may be predicted. Examples are presented to illustrate the use of these charts and a limited number of experiments conducted upon a glass full-floating bearing to verify some results of the analysis are reported. The floating sleeve can operate over a wide range of speeds for a given shaft speed, the exact value depending principally upon the ratio of clearances and upon the ratio of radii of the bearing. Lower operating temperatures at high rotative speeds are to be expected by using a full-floating bearing. This lower operating temperature would be obtained at the expense of the load-carrying capacity of the bearing if, for comparison, the clearances remain the same in both bearings. A full-floating bearing having the same load capacity as a conventional journal bearing may be designed if decreased clearances are allowable.
Date: January 28, 1947
Creator: Shaw, M. C. & Nussdorfer, T. J.
Partner: UNT Libraries Government Documents Department

Theoretical Analysis and Bench Tests of a Control-Surface Booster Employing a Variable Displacement Hydraulic Pump

Description: From Summary: "The NACA is conducting a general investigation of servo-mechanisms for use in powering aircraft control surfaces. This paper presents a theoretical analysis and the results of bench tests of a control-booster system which employs a variable displacement hydraulic pump. The booster is intended for use in a flight investigation to determine the effects of various booster parameters on the handling qualities of airplanes. Such a flight investigation would aid in formulating specific requirements concerning the design of control boosters in general."
Date: January 28, 1947
Creator: Mathews, Charles W. & Kleckner, Harold F.
Partner: UNT Libraries Government Documents Department

Theoretical investigation of thrust augmentation of turbojet engines by tail-pipe burning

Description: Report presenting a theoretical analysis of thrust augment of turbojet engines by tail-pipe burning and charts from which the thrust augmentation produced may be evaluated from the normal engine data and performance of the tail-pipe burner. Results regarding general curves and illustrative curves are provided.
Date: January 28, 1947
Creator: Bohanon, H. R. & Wilcox, E. C.
Partner: UNT Libraries Government Documents Department

Altitude-Wind-Tunnel Investigation of R-4360-18 Power-Plant Installation for XR60 Airplane, 3, Performance of Induction and Exhaust Systems

Description: From Summary: "A study has been made of the performance of the induction and the exhaust systems on the XR60 power-plant installation as part of an investigation conducted in the Cleveland altitude wind tunnel. Altitude flight conditions from 5000 to 30,000 feet were simulated for a range of engine powers from 750 to 3000 brake horsepower."
Date: March 28, 1947
Creator: Dupree, David T. & Hawkins, W. Kent
Partner: UNT Libraries Government Documents Department

Evaluation of Gust and Draft Velocities from Flights of P-61C Airplanes within Thunderstorms July 24, 1946 to August 6, 1946 at Orlando, Florida

Description: The results obtained from gust and draft velocity measurements within thunderstorms for the period July 24, 1946 to August 6, 1946 at Orlando, Florida are presented herein. These data are summarized in tables I and II and are of the type presented in reference 1 for previous flights. In two thunderstorm traverses, indications of ambient-air temperature were obtained from photo-observer records. These data are summarized in table III.
Date: March 28, 1947
Creator: Tolefson, Harold B.
Partner: UNT Libraries Government Documents Department

Longitudinal stability and control characteristics of a semispan airplane model with a swept-back tail from tests at transonic speeds by the NACA wing-flow method

Description: Report presenting an investigation using the NACA wing-flow method to determine the longitudinal stability and control characteristics of a semispan airplane model with a wing of conventional plan form and a horizontal tail swept back 45 degrees at transonic speeds. Measurements were made of lift and angle of attack for trim at several stabilizer and elevator settings.
Date: March 28, 1947
Creator: Zalovcik, John A. & Sawyer, Richard H.
Partner: UNT Libraries Government Documents Department

An Investigation of Convergent-Divergent Diffusers at Mach Number 1.85

Description: An investigation has been conducted in the Cleveland 18- by 18-inch supersonic tunnel at a Mach number of 1.85 and angles of attack from 0 deg to 5 deg to determine optimum design configurations for a convergent-divergent type of supersonic diffuser with a subsonic diffuser of 5 deg included divergence angle. Total pressure recoveries in excess of theoretical recovery across a normal shock at a free-stream Mach number of 1.85 wore obtained with several configurations.
Date: April 28, 1947
Creator: Wyatt, DeMarquis D. & Hunczak, Henry R.
Partner: UNT Libraries Government Documents Department

Wind-tunnel development of optimum double-slotted-flap configurations for seven thin NACA airfoil sections

Description: Report presenting an investigation in the two-dimensional low-turbulence tunnels to develop optimum double-slotted-flap configurations for seven thin NACA airfoil sections. Each was equipped with the same flaps and measured at the same Reynolds numbers. Results regarding the lift characteristics and pitching moment are provided.
Date: April 28, 1947
Creator: Cahill, Jones F. & Racisz, Stanley F.
Partner: UNT Libraries Government Documents Department

Effects of Variations in Forebody and Afterbody Dead Rise on the Resistance and Spray Characteristics of the 22ADR Class VPB Airplane: Langley Tank Model 207, TED No. NACA 2361

Description: From Summary: "An investigation was made to determine the effects of changes in the amount and distribution of forebody and afterbody dead rise on the hydrodynamic resistance and spray characteristics of a 1/11-size model of the Bureau of Aeronautics design No. 22ADR class VPB airplane. The variations in dead rise within the range investigated had no significant effects on resistance or trim, free to trim, or on resistance or trimming moment, fixed in trim. The coordinates of the peaks of the bow-spray blisters, with reference to the model, were measured at low speeds, and it was found that the model with the low dead rise at the bow had the lowest blisters."
Date: August 28, 1947
Creator: Clement, Eugene P. & Daniels, Charles J.
Partner: UNT Libraries Government Documents Department

A torsional stiffness criterion for preventing flutter of wings of supersonic missiles

Description: From Summary: "A formula, based on a semirational analysis, is presented for estimating the torsional stiffness necessary to prevent flutter of a sweptback or unswept uniform wing that attains supersonic speeds. Results of missile flights at speeds up to Mach number 1.4 demonstrate the usefulness of the formula."
Date: August 28, 1947
Creator: Budiansky, Bernard; Kotanchik, Joseph N. & Chiarito, Patrick T.
Partner: UNT Libraries Government Documents Department

Free-Spinning-Tunnel Tests of a 1/24-Scale Model of the McDonnell XP-88 Airplane with a VEE Tail

Description: An investigation of the spin and recovery characteristics of a 1/24-scale model of the McDonnell XP-88 airplane has been conducted in the Langley 20-ft free-spinning tunnel. Results of tests with a conventional tail have been previously reported; the results presented herein are for the model with a vee tail installed. The effects of control settings and movements on the erect and inverted spin and recovery characteristics of the model. In the normal loading were determined. Tests of the model in the long-range loading also were made. The investigation included leading-edge-flap, spin-recovery-parachute, and rudder-pedal-force tests. The recovery characteristics of the model were satisfactory for the normal loading. Deflecting the leading-edge flaps improved recoveries. The results indicated that with the external wing tanks installed (long-range loading) recoveries may be poor and, therefore, if a spin is inadvertently entered in this condition the tanks should be jettisoned if recovery does not appear imminent immediately after it is attempted. A 10-foot spin-recovery tail parachute with a towline 40 feet long and a drag coefficient of 0.63 was found to be effective for spin recovery. The rudder pedal force required for spin recovery was indicated to be within the capabilities of the pilot.
Date: November 28, 1947
Creator: Berman, Theodore
Partner: UNT Libraries Government Documents Department

Ground Tests of a Radial Air-Cooled Engine to Correct a Poor Circumferential Pressure-Recovery Distribution

Description: "This report presents the results of the tests of a power-plant installation to improve the circumferential pressure-recovery distribution at the face of the engine. An underslung "C" cowling was tested with two propellers with full cuffs and with a modification to one set of cuffs. Little improvement was obtained because the base sections of the cuffs were stalled. A set of guide vanes boosted the over-all pressures and helped the pressure recoveries for a few of the cylinders" (p. 1).
Date: January 28, 1948
Creator: Gallagher, James J.
Partner: UNT Libraries Government Documents Department

Performance of J-33-A-21 and J-33-A-23 Compressors With and Without Water Injection

Description: "In an investigation of the J-33-A-21 and the J-33-A-23 compressors with and without water injection, it was discovered that the compressors reacted differently to water injection although they were physically similar. An analysis of the effect of water injection on compressor performance and the consequent effect on matching of the compressor and turbine components in the turbojet engine was made. The analysis of component matching is based on a turbine flow function defined as the product of the equivalent weight flow and the reciprocal of the compressor pressure ratio" (p. 1).
Date: January 28, 1948
Creator: Beede, William L.
Partner: UNT Libraries Government Documents Department

Vibration survey of blades in 19XB axial-flow compressor: 3 - preliminary engine investigation

Description: Strain gages were used to measure blade vibrations possibly causing failure in the 10-stage compressor of the 19XB jet-propulsion engine. The seventh and tenth stages were of great concern as a result of failures experienced by the manufacturer. Strain-gage records were obtained from all stages during acceleration, deceleration, and constant speed runs. Curves are presented herein showing the maximum allowable vibratory stress for a given speed, the change of the damping coefficient with the mounting of a strain gage at the base of the blade, the effect of rotor speed, on blade natural frequency, and the effect of the order of first bending-mode vibration on stress. It was found that for all stages the lower the order of vibration the higher the stress but no destructive vibrations were detected.
Date: January 28, 1948
Creator: Meyer, André J., Jr. & Calvert, Howard F.
Partner: UNT Libraries Government Documents Department

Ditching Tests of a 1/24-Scale Model of the Lockheed XR60-1 Airplane, TED No. NACA 235

Description: "The ditching characteristics of the Lockheed XR60-1 airplane were determined by tests of a 1/24-scale dynamic model in calm water at the Langley tank no. 2 monorail. Various landing attitudes, flap settings, speeds, and conditions of damager were investigated. The ditching behavior was evaluated from recordings of decelerations, length of runs, and motions of the model" (p. 1).
Date: May 28, 1948
Creator: Fisher, Lloyd J. & Cederborg, Gibson A.
Partner: UNT Libraries Government Documents Department

Free-flight investigation of 16-inch diameter supersonic ram-jet unit

Description: Report presenting an investigation of a series of 16-inch-diameter ramjet engine in free flight in order to determine the performance of ramjet units in flight at supersonic speeds and to study methods for improving the performance. Results regarding the telemeter data recorded by ground stations, static pressures, variation of altitude with time after release, variation of flight velocities, and fuel-air ratio are provided. Partial failure of the measuring equipment prevented a complete evaluation of engine performance.
Date: May 28, 1948
Creator: Kinghorn, George F. & Disher, John H.
Partner: UNT Libraries Government Documents Department