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Effects of Ice Formations on Airplane Performance in Level Cruising Flight

Description: "A flight investigation in natural icing conditions was conducted by the NACA to determine the effect of ice accretion on airplane performance. The maximum loss in propeller efficiency encountered due to ice formation on the propeller blades was 19 percent. During 87 percent of the propeller icing encounters, losses of 10 percent or less were observed" (p. 1).
Date: May 1948
Creator: Preston, G. Merritt & Blackman, Calvin C.
Partner: UNT Libraries Government Documents Department
open access

Investigation of Effectiveness of Air-Heating a Hollow Steel Propeller for Protection Against Icing 1: Unpartitioned Blades

Description: From Summary: "An investigation to determine the effectiveness of icing protection afforded by air-heating hollow steel unpartitioned propeller blades has been conducted In the NACA Cleveland icing research tunnel. The propeller used was a production model modified with blade shank and tip openings to permit internal passage of heated air. Blade-surface and heated-air temperatures were obtained and photographic observations of Ice formations were made with variations In icing intensity and heat… more
Date: May 1948
Creator: Mulholland, Donald R. & Perkins, Porter J.
Partner: UNT Libraries Government Documents Department
open access

Investigation of Effectiveness of Air-Heating a Hollow Steel Propeller for Protection Against Icing. 2: 50% Impartitioned Blades

Description: From Summary: "The icing protection afforded an internal air-heated propeller blade by radial partitioning at 50-percent chord to confine the heated air to the forward half of the blade was determined in the NACA Cleveland icing research tunnel. A modified production-model hollow steel propeller, was used for the investigation. Temperatures of the blade surfaces for several heating rates were measured under various tunnel icing conditions. Photographic observations of ice formations on blade su… more
Date: May 1948
Creator: Perkins, Porter J. & Mulholland, Donald R.
Partner: UNT Libraries Government Documents Department
open access

Investigation of Effectiveness of Air-Heating a Hollow Steel Propeller for Protection Against Icing. 3: 25% Partitioned Blades

Description: From Summary: "The icing protection obtained from an internally air-heated propeller blade partitioned to confine the heated air forward of 25-percent chord was investigated in the NACA Cleveland icing research tunnel. A production-model hollow steel propeller was modified with an Internal radial partition at 25-percent chord and with shank and tip openings to admit and exhaust the heated air. Temperatures were measured on the blade surfaces and in the heated-air system during tunnel icing cond… more
Date: May 1948
Creator: Mulholland, Donald R. & Perkins, Porter J.
Partner: UNT Libraries Government Documents Department
open access

An Electric Thrust Meter Suitable for Flight Investigation of Propellers

Description: A lightweight instrument that utilizes resistance-wire electric strain gases to measure propeller-shaft thrust has been developed. A wind-tunnel investigation on a propeller installed, on a single-engine pursuit airplane showed that the instrument gave a reliable indication of propeller-shaft thrust to an accuracy of +/-2 percent within its calibrated range. No attempt was made to determine the relation of indicated shaft thrust to net propeller thrust.
Date: May 9, 1949
Creator: Perkins, Porter J., Jr. & Millenson, Morton B.
Partner: UNT Libraries Government Documents Department
open access

Analysis of Circular Shell-Supported Frames

Description: From Summary: "This paper deals with the single problem if circular shell-supported frames subjected to concentrated loadings. A mathematical attack is developed and presented in the form of nondimensional-coefficient curves."
Date: May 1944
Creator: Wignot, J. E.; Combs, Henry & Ensrud, A. F.
Partner: UNT Libraries Government Documents Department
open access

Lightning Discharges to Aircraft and Associated Meteorological Conditions

Description: A summary is given of information on atmospheric electrical discharges to aircraft and associated meteorological conditions. Information is given that is designed to give a fairly comprehensive view of the underlying principles of meteorology and atmospheric electricity. Of special interest to pilots are lists of procedures of flight conduct and aircraft maintenance recommended foe avoiding or minimizing the hazards of disruptive electrical discharges and other severe conditions near thundersto… more
Date: May 1946
Creator: Harrison, L. P.
Partner: UNT Libraries Government Documents Department
open access

Spin Tests of a Low-Wing Monoplane to Investigate Scale Effect in the Model Test Range

Description: "Concurrent tests were performed on a 1/16 and a 1/20 scale model (wing spans of 2.64 and 2.11 ft. respectively) of a modern low wing monoplane in the NACA 15 foot free-spinning wind tunnel. Results are presented in the form of charts that afford a direct comparison between the spins of the two models for a number of different conditions. Qualitatively, the same characteristic effects of control disposition, mass distribution, and dimensional modifications were indicated by both models" (p. 1).
Date: May 1941
Creator: Donlan, Charles J.
Partner: UNT Libraries Government Documents Department
open access

Biaxial Fatigue Strength of 24S-T Aluminum Alloy

Description: Note presenting an investigation to determine the fatigue-strength values for 24S-T aluminum alloy when subjected to various ratios of biaxial stresses. The stresses considered were both tensile. The results indicated that uniaxial fatigue-strength values in the longitudinal direction cannot be used to predict the fatigue strength, and that biaxial fatigue strength may be as low as 50 percent of the uniaxial fatigue strength.
Date: May 1949
Creator: Marin, Joseph & Shelson, William
Partner: UNT Libraries Government Documents Department
open access

Wing-tunnel investigation of effects of forward movements of transition on section characteristics of a low-drag airfoil with a 0.24-chord sealed plain aileron

Description: Report presenting an investigation to determine the effects of forward movements of transition on the section characteristics of a 12-percent-thick low-drag airfoil section with a 0.24-chord sealed plain aileron. Section lift and aileron section hinge-moment and seal-pressure characteristics were determined at a specific Reynolds number for aerodynamically smooth surfaces and with fixed transition at two different points.
Date: May 1948
Creator: Racisz, Stanley F. & Cahill, Jones F.
Partner: UNT Libraries Government Documents Department
open access

Critical Axial-Compressive Stress of a Curved Rectangular Panel With a Central Longitudinal Stiffener

Description: "A theoretical solution is presented for the critical axial-compressive stress of a simply supported curved rectangular panel having a central longitudinal stiffener offering no torsional restraint. The results are presented in the form of computed curves and tables. Because a panel of moderate or large curvature buckles in compression at a stress lower than the theoretical value, a method is suggested to aid in determining the critical stress for use in design" (p. 1).
Date: May 1949
Creator: Schildcrout, Murry & Stein, Manuel
Partner: UNT Libraries Government Documents Department
open access

Comparison of Pitching Moments Obtained During Seaplane Landings With Values Predicted by Hydrodynamic Impact Theory

Description: Report presenting an investigation of pitching moments and center-of-pressure locations obtained from a landing investigation in smooth water of a conventional flying boat as compared to values predicted by general hydrodynamic impact theory. Landings were generally moderate and covered as wide a range of trim and velocities as practical. Results regarding the center of pressure and pitching moments are provided.
Date: May 1949
Creator: Haines, Gilbert A.
Partner: UNT Libraries Government Documents Department
open access

Oxidation Characteristics of Molybdenum Disulfide and Effect of Such Oxidation on Its Role as a Solid-Film Lubricant

Description: Note presenting an investigation conducted to determine the oxidation characteristics of molybdenum disulfide and to determine the effect of such oxidation on its role as a solid-film lubricant. A coating of molybdenum disulfide serving as a high-temperature solid-film lubricant maintained low coefficient-of-friction values during its oxidation as long as an effective subfilm of the molybdenum disulfide remained.
Date: May 1949
Creator: Godfrey, Douglas & Nelson, Erva C.
Partner: UNT Libraries Government Documents Department
open access

Compressive Buckling of Flat Rectangular Metalite Type Sandwich Plates With Simply Supported Loaded Edges and Clamped Unloaded Edges

Description: Note presenting a theoretical solution for the problem of the compressive buckling of flat rectangular Metalite type sandwich plates with simply supported loaded edges and clamped unloaded edges. The solution is based on the general small-deflection theory for flat sandwich plates developed in a previous report. Results regarding stability orientation and buckling curves, comparison with approximate solution, correction for plasticity, and comparison of theory and experiment are provided.
Date: May 1949
Creator: Seide, Paul
Partner: UNT Libraries Government Documents Department
open access

Design and Performance of Family of Diffusing Scrolls with Mixed-flow Impeller and Vaneless Diffuser

Description: Report presenting a study of a family of diffusing scrolls designed for use with a mixed-flow impeller and a small-diameter vaneless diffuser. Results regarding a comparison of performance of scrolls and comparison of performance of various compressor configurations are provided.
Date: May 1948
Creator: Brown, W. Byron & Bradshaw, Guy R.
Partner: UNT Libraries Government Documents Department
open access

Stability derivatives of triangular wings at supersonic speeds

Description: Report presenting the analysis of the stability derivatives of low-aspect-ratio triangular wings at subsonic and supersonic speeds, which is extended to apply to triangular wings having large vertex angles and traveling at supersonic speeds.
Date: May 1948
Creator: Ribner, Herbert S. & Malvestuto, Frank S., Jr.
Partner: UNT Libraries Government Documents Department
open access

Flight Measurements of the Flying Qualities of Five Light Airplanes

Description: Note presenting results of an investigation made to determine measurements of stability, controllability, and stalling characteristics of five light airplanes. Results regarding the longitudinal stability and control characteristics, lateral stability and control characteristics, stalling characteristics, spinning characteristics, and effect of slots on flying qualities are provided.
Date: May 1948
Creator: Hunter, Paul A.
Partner: UNT Libraries Government Documents Department
open access

Notes on the Lagrangian Multiplier Method in Elastic-Stability Analysis

Description: "New application of the Lagrangian multiplier method to stability analysis are described by means of elementary examples. The use of the method in analyzing the stability of (a) clamped plates in shear and (b) plate-stiffener combinations is demonstrated. A detailed analysis for finding upper and lower limits to critical stresses of clamped rectangular plates is presented in the appendix" (p. 1).
Date: May 1948
Creator: Budiansky, Bernard; Hu, Pai C. & Connor, Robert W.
Partner: UNT Libraries Government Documents Department
open access

Buckling Stresses of Clamped Rectangular Flat Plates in Shear

Description: "By consideration of antisymmetrical, as well as symmetrical, buckling configurations, the theoretical shear buckling stresses of clamped rectangular flat plates are evaluated more correctly than in previous work. The results given, which represent the average of upper- and lower-limit solutions obtained b the Lagrangian multiplier method, are within 1 1/4 percen of true buckling stresses" (p. 1).
Date: May 1948
Creator: Budiansky, Bernard & Connor, Robert W.
Partner: UNT Libraries Government Documents Department
open access

Approximate Relations and Charts for Low-Speed Stability Derivatives of Swept Wings

Description: Contains derivations, based on a simplified theory, of approximate relations for low-speed stability derivatives of swept wings. Method accounts for the effects and, in most cases, taper ratio. Charts, based on the derived relations, are presented for the stability derivatives of untapered swept wings. Calculated values of the derivatives are compared with experimental results.
Date: May 1948
Creator: Toll, Thomas A. & Queijo, M. J.
Partner: UNT Libraries Government Documents Department
open access

Effect of Shear Lag on Bending Vibration of Box Beams

Description: "An analytical investigation is made of the effect of shear lag on the bending vibration of wings that are designed essentially as shallow box beams, and a procedure is outlined for incorporating this effect in the determination of bending modes and frequencies. Numerical examples show that shear-lag action in a box beam can have a large influence on its vibration characteristics. The calculations indicate that even though only a small shear-lag action may be observed in a simple static deflect… more
Date: May 1948
Creator: Anderson, Roger A. & Houbolt, John C.
Partner: UNT Libraries Government Documents Department
open access

An evaluation of some approximate methods of computing landing stresses in aircraft

Description: Report presenting an investigation to obtain some information concerning the nature and magnitude of the errors involved in computing the landing stresses for large and relatively flexible aircraft when several simplifying assumptions are made. Results regarding the exact solution and approximate solutions are provided. The results suggest that a satisfactory treatment of the landing problem may possibly be obtained from an analysis which assumes that, in landing, the aircraft is an elastic str… more
Date: May 1948
Creator: Stowell, Elbridge Z.; Houbolt, John C. & Batdorf, S. B.
Partner: UNT Libraries Government Documents Department
open access

Theoretical distribution of lift on thin wings at supersonic speeds (An extension)

Description: Report presenting a derivation of a point-source method based on the linearized theory for obtaining the pressure coefficient on thin wings at supersonic speeds. The analysis is continued to formulate the velocity potential for regions influenced by so-called subsonic trailing edges.
Date: May 1948
Creator: Evvard, John C.
Partner: UNT Libraries Government Documents Department
open access

Investigation of an Approximately 0.178-Chord-Thick NACA 6-Series-Type Airfoil Section Equipped With Sealed Internally Balanced 0.20-Chord Ailerons and With a 0.05-Chord Tab

Description: Note presenting hinge-moment, lift, and drag measurements made on an approximately 0.178-chord-thick NACA 6-series-type airfoil section equipped with sealed internally balanced 0.20-chord ailerons and with a 0.05-chord tab. The purpose of the investigation was to obtain the effects of aileron contour and internal-balance chord on the aileron section hinge-moment characteristics and to determine the tab effectiveness in reducing the aileron section hinge moments.
Date: May 1948
Creator: Visconti, Fioravante
Partner: UNT Libraries Government Documents Department
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