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Investigations Relating to the Extension of Laminar Flow by Means of Boundary-Layer Suction Through Slots

Description: Note presenting experimental investigations of boundary-layer suction through slots as a means of increasing the extent of laminar flow on airfoil sections. The results show that, with the use of suitable slots, substantial increases in the extent of laminar flow can be achieved by boundary-layer control with only a small expenditure of power. Results regarding slot geometry and arrangement, suction slots in an unfavorable pressure gradient, suction slots in a favorable pressure gradient, and d… more
Date: October 1949
Creator: Loftin, Laurence K., Jr. & Burrows, Dale L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Quantitative Study of Variations in Concentration of Glycerol and Aerosol OT on Foaming Volume of Oil at Room Temperature

Description: "The amount of foam that can be formed in the presence of certain pure chemical agents was investigated by a new method. The effect of variations in concentration and proportion of Aerosol OT and glycerol was studied and the effects of various other mixtures have been given for comparison. Both Gulf Agent and Aerosol-OT - glycerol mixtures, when present in comparable amounts, prohibited the formation of the normal volumes of foam to the same extent and in the optimum cases reduced it to only on… more
Date: April 1949
Creator: McBain, J. W. & Ross, Sydney
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Effect of Various Compounds in Use With Airplane Engines Upon Foaming of Aircraft Lubricating Oil

Description: Report presenting an investigation of aircraft lubricating oil that is contaminated with various materials used in connection with airplane engines or contained in the fuel. Over 60 of the materials have been tested to determine their influence on the foaming of an aircraft lubricating oil. All but 13 of the compounds were found to have a small or negligible effect, but the other 13 were found to be strong foaming agents.
Date: April 1949
Creator: McBain, J. W. & Woods, W. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Buckling of Parallel Simply Supported Tension and Compression Members Connected by Elastic Deflectional Springs

Description: Note presenting an investigation of the problem of the buckling of parallel simply supported tension and compression members connected by equally stiff and equally spaced elastic deflection springs as an approximation to the problem of the effect of finite stiffness of ribs and tension surface on the buckling load of the compression surface of a wing. Charts relating compressive buckling load, deflectional spring stiffness, and the ratio of the flexural stiffness of the members are given for te… more
Date: February 1949
Creator: Seide, Paul & Eppler, John F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A Generalized Theoretical Investigation of the Hydrodynamic Pitching Moments Experienced by V-Bottom Seaplanes During Step-Landing Impacts and Comparisons With Experiment

Description: Note presenting a theoretical investigation made of the hydrodynamic pitching moments experienced by V-bottom seaplanes during step-landing impacts. The entire immersion process is analyzed from the instant of initial contact until the seaplane rebounds from the water surface.
Date: June 1948
Creator: Milwitzky, Benjamin
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A flight investigation to increase the safety of a light airplane

Description: Report presenting information about a series of modifications incorporated into light airplanes to increase safety, including decreasing the wing incidence, increasing the wing washout, increasing the area and aspect ratio of the horizontal and vertical tails, moving the elevators out of propeller slipstreams, depressing the thrust axis, and limiting the rudder travel. The new inherent safety characteristics and effects on the airplane's performance are provided.
Date: March 1947
Creator: Hunter, P. A. & Vensel, J. R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Compressive Buckling of Simply Supported Plates With Longitudinal Stiffeners

Description: "Charts are presented for the analysis of the stability under compression of simply supported rectangular plates with one, two, three, and an infinite number of identical equally spaced longitudinal stiffeners that have zero torsional stiffness" (p. 1).
Date: March 1949
Creator: Seide, Paul & Stein, Manuel
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A General Method of Selecting Foam Inhibitors

Description: Note presenting a criterion for selecting foam inhibitors from insoluble liquids that form emulsions with the foaming liquid. By determining the surface tensions of the foaming liquid and of the additive saturated with that liquid and the interfacial tension between them, spreading and entering coefficients may be calculated. A mechanism of foam inhibition is also described.
Date: May 1946
Creator: Robinson, J. V. & Woods, W. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Effect of Centrifugal Force on the Elastic Curve of a Vibrating Cantilever Beam

Description: Report presenting the results of a study to determine the effect of rotation on the dynamic-stress distribution in vibrating cantilever beams. Both theoretical and experimental results are obtained by means of stroboscopic photographs and strain gauges. Both types of results indicated that the introduction of centrifugal force had no effect on the maximum dynamic-stress locations in a vibrating cantilever beam fixed at the center of rotation within the investigated speed range.
Date: February 1947
Creator: Simpkinson, Scott H.; Eatherton, Laurel J. & Millenson, Morton B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Linear theory of boundary effects in open wind tunnels with finite jet lengths

Description: Report in two parts: one examines the boundary conditions for an open wind tunnel with special references to the effects of the closed entrance and exit sections, while the other derives solutions of four types of two-dimensional open tunnels, including one in which the pressures on the two free surfaces are not equal.
Date: March 1949
Creator: Katzoff, Samuel; Gardner, Clifford S.; Diesendruck, Leo & Eisenstadt, Bertram J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Boundary-Induced Upwash for Yawed and Swept-Back Wings in Closed Circular Wind Tunnels

Description: Report presenting a determination of the tunnel-induced velocities for yawed and swept-back airfoils in a closed circular wind tunnel. Calculations were performed for elemental horseshoe vortices with one tip of the bound vortex on the tunnel axis for a range of yaw angles and bound-vortex lengths.
Date: May 1947
Creator: Eisenstadt, Bertram J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Matrix Methods for Calculating Cantilever-Beam Deflections

Description: Note presenting the method of numerical integration for calculation of beam deflection in matrix form to give it the advantages which are inherent in an influence-coefficient method. Examples are presented to show that the use of weighted matrices reduces the calculation time required to obtain a desired degree of accuracy.
Date: March 1949
Creator: Benscoter, Stanley U. & Gossard, Myron L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Data on Optimum Length, Shear Strength, and Tensile Strength of Age-Hardened 17S-T Machine-Countersunk Rivets in 75S-T Sheet

Description: Report presenting a series of tensile-strength and shear-strength tests made on age-hardened 17S-T rivets machine-countersunk in 75S-T sheets. The results of the tests indicated that the joints can be made satisfactorily with regard to both flushness and strength if the ratio of buck to diameter is kept to a certain value.
Date: March 1947
Creator: Schuette, Evan H. & Niles, Donald E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Flight Measurements of Helicopter Blade Motion With a Comparison Between Theoretical and Experimental Results

Description: Note presenting photographic records of the behavior of a blade in flight as obtained with a conventional single-rotor helicopter. The results of the measurements of flapping motion, in-plane motion, and blade distortions are presented for selected conditions of flight at tip-speed ratios ranging from 0.12 to 0.25. Plots of blade twisting and blade bending in the plane of flapping are presented for a sample case.
Date: April 1947
Creator: Myers, Garry C., Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The streamline pattern in the vicinity of an oblique airfoil

Description: "A method for determining the streamwise flow pattern of a nonviscous incompressible fluid about an oblique airfoil from the corresponding flow pattern about the airfoil in normal position is presented and illustrated in two examples. The method can be extended to account approximately for compressibility effects by applying the Prandtl-Glauert correction factor to the flow pattern that is normal to the leading edge of the airfoil. The method is expected to be useful in determining the shape of… more
Date: March 1947
Creator: Watkins, Charles E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Effect of forebody warp on the hydrodynamic qualities of a hypothetical flying boat having a hull length-beam ratio of 15

Description: Report of an investigation of the effect of forebody warp on the hydrodynamic qualities of a hypothetical flying boat with a hull length-beam ratio of 15 in smooth water and in waves. Warping the forebody planing bottom was found to appreciably increase the range of stable trim between the lower and upper trim limits of stability, although the center-of-gravity limits of stability were reduced.
Date: March 1949
Creator: Carter, Arthur W. & Weinstein, Irving
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Flight Tests of a Helicopter in Autorotation, Including a Comparison With Theory

Description: Note presenting the results of glide performance tests conducted on a test helicopter with its original production blades in the autorotation condition. The data was reduced to coefficient form, and performance at standard sea-level conditions were calculated.
Date: April 1947
Creator: Gessow, Alfred & Myers, Garry C., Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Data on the Compressive Strength of 75S-T6 Aluminum-Alloy Flat Panels with Longitudinal Extruded Z-Section Stiffeners

Description: "The experimental results are presented for a part of an investigation of the compressive strength of 75S-T6 aluminum-alloy flat panels with longitudinal extruded Z-section stiffeners. This part of the investigation is concerned with panels in which the ratio of the thickness of the stiffener material to the skin material varies from 0.4 to 1.0 and the ratio of stiffener spacing to skin thickness varies from 15 to 40" (p. 1).
Date: March 1949
Creator: Hickman, William A. & Dow, Norris F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Experimental and calculated characteristics of several NACA 44-series wings with aspect ratios of 8, 10, and 12 and taper ratios of 2.5 and 3.5

Description: The aerodynamic characteristics of seven unswept tapered wings were determined by calculation from two-dimensional data and by wind-tunnel tests in order to demonstrate the accuracy of the calculations and to show some of the effects of aspect ratio, taper ratio, and root thickness-chord ratio. The characteristics were calculated by the usual application of the lifting-line theory which assumes linear section lift curves and also by an application of the theory which allows the use of nonlinear… more
Date: May 1947
Creator: Neely, Robert H.; Bollech, Thomas V.; Westrick, Gertrude C. & Graham, Robert R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

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

Description: Note presenting an investigation of the laminar boundary layer and the position of the transition point on a heated flat plate. The Reynolds number of transition was found to decrease as the temperature of the plate is increased. Results regarding the effect of surface temperature, effect of roughness elements, mean-velocity profile near a heated wall, instability of inflection-point profiles, and laminar separation and transition are provided.
Date: April 1947
Creator: Liepmann, Hans W. & Fila, Gertrude H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A Discussion of the Application of the Prandtl-Glauert Method to Subsonic Compressible Flow Over a Slender Body of Revolution

Description: Note presenting an analysis of the use of the Prandtl-Glauert method for subsonic potential flow of a compressible fluid. This paper specifically focuses on the difference between the two- and three-dimensional flow when using this method.
Date: September 1946
Creator: Lees, Lester
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A preliminary study of a propeller powered by gas jets issuing from the blade tips

Description: From Summary: "Computations are made of the performance of a propeller designed to develop 56 thrust horsepower at 100 miles per hour. The fuel consumption of the jet-operated propeller would be considerably higher than that of a reciprocating engine and a propeller. The lighter weight of the jet-operated propeller will result in a lighter weight of engine plus fuel for short-range flights. A theoretical analysis is made of a propeller powered by gas jets issuing from the blade tips."
Date: November 1946
Creator: Sanders, J. C. & Sanders, N. D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Comparison of relative sensitivities of the knock limits of two fuels to six engine variables

Description: Report presenting knock testing of a sensitive fuel and a relatively insensitive fuel in a full-scale air-cooled cylinder. Six engine variables were investigated: fuel-air ratio, compression ratio, inlet-air temperature, spark advance, exhaust pressure, and cylinder temperature.
Date: August 1946
Creator: Cook, Harvey A.; Held, Louis F. & Pritchard, Ernest I.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Flow Tests of an NACA-Designed Supercharger Inlet Elbow and the Effects of Various Components on the Flow Characteristics at the Elbow Outlet

Description: Note presenting an investigation on a supercharger inlet elbow designed to have a uniform velocity distribution at the outlet with a minimum pressure loss through the bend. The effects of a vane, an impeller-shaft housing, and the combination of the two on the outlet-velocity distribution and total pressure drop through the elbow were determined.
Date: October 1946
Creator: Guentert, D. C.; Todd, D. J. & Simmons, W. P., Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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