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Axial Fatigue Tests at Zero Mean Stress of 24S-T Aluminum-Alloy Sheet With and Without a Circular Hole
"Axial fatigue tests were made on 189 coupon specimens of 0.032-inch 24S-T aluminum-alloy sheet and a few supplementary specimens of 0.004-inch sheet. The mean load was zero. The specimens were restrained against lateral buckling by lubricated solid guides described in a previous report on this project. About two-thirds of the 0.032-inch specimens were plain coupons nominally free from stress raisers. The remainder contained a 0.1285-inch drilled hole at the center where the reduced section was 0.5 inch wide" (p. 1).
Date:
November 1944
Creator:
Brueggeman, W. C.; Mayer, M., Jr. & Smith, W. H.
System:
The UNT Digital Library
The "Limiting Line" in Mixed Subsonic and Supersonic Flow of Compressible Fluids
"It is well known that the vorticity for any fluid element is constant if the fluid is non-viscous and the change of state of the fluid is isentropic. When a solid body is placed in a uniform stream, the flow far ahead of the body is irrotational. Then if the flow is further assumed to be isentropic, the vorticity will be zero over the whole filed of flow. In other words, the flow is irrotational. For such flow over a solid body, it is shown by Theodorsen that the solid body experiences no resistance" (p. 1).
Date:
November 1944
Creator:
Tsien, Hsue-Shen
System:
The UNT Digital Library
The Chemical Action of Oils on Single Crystals of Metals
Note presenting a study of the chemical action of oils on large single crystals of metals in the presence of various gases, with special emphasis placed on the influence of crystal plane. The studies primarily have been concerned with four metals: silver, copper, lead, and iron and four types of oil: pure hydrocarbons with mineral oil as representative, oiliness agents with stearic acid as representative, chemical polishing agents with tricresyl phosphate as representative, and commercial oils with new and used aviation oils as representatives. The methods used in preparing large single crystals of various metals are briefly discussed.
Date:
November 1945
Creator:
Gwathmey, A. T.; Leidheiser, H. & Smith, G. P.
System:
The UNT Digital Library
A velocity-correction formula for the calculation of transonic Mach number distributions over diamond-shaped airfoils
Report presenting a velocity-correction formula for the purpose of calculating, from the known Mach number distribution for a diamond-shaped airfoil at a stream Mach number of 1.0, Mach number distributions on the same airfoil at speeds from a Mach number of about 0.8 to shock-attachment Mach number. An expression for the rate of change of local Mach number with stream Mach number is derived and an explicit equation for the drag coefficient as a function of stream Mach number and thickness ratio is given.
Date:
November 1951
Creator:
Ivey, H. Reese & Harder, Keith C.
System:
The UNT Digital Library
Heat Capacity Lag in Gases
Note presenting a review of the literature on the sonic studies of the problem of the excitation of molecular vibrations by collision. The theory on which the interpretation of almost all the sonic work has been based is discussed rather qualitatively in some detail. Results concerning techniques, principal experimental programs, and an interpretation of the results are provided.
Date:
November 1951
Creator:
Walker, Richard
System:
The UNT Digital Library
Langley full-scale-tunnel investigations of the maximum-lift and stalling characteristics of a trapezoidal wing of aspect ratio 4 with circular-arc airfoil sections
Report presenting an investigation of the results at high Reynolds numbers and low Mach numbers to determine the maximum-lift and stalling characteristics of an aspect-ratio-4 trapezoidal wing with 10-percent-thick, circular-arc airfoil sections. Testing occurred measurements of lift, drag, and pitching-moment coefficients of the basic wing and of the wing with 0.20-chord droop-nose and rear flaps deflected alone and in combination with one another.
Date:
November 1952
Creator:
Lange, Roy H.
System:
The UNT Digital Library
Effects of independent variations of mach number and reynolds number on the maximum lift coefficients of four NACA 6-series airfoil sections
Report presenting an investigation in the low-turbulence pressure tunnel to determine the effects of Mach and Reynolds number on the maximum lift characteristics of the NACA 65-006, 64-009, 64-210, and 64(sub 2)-215 airfoil sections in smooth and leading-edge roughness conditions. A range of Mach and Reynolds numbers were explored.
Date:
November 1952
Creator:
Racisz, Stanley F.
System:
The UNT Digital Library
Studies on Von Kármán's Similarity Theory and Its Extension to Compressible Flows: A Critical Examination of Similarity Theory for Incompressible Flows
Note presenting an investigation of three theories: the momentum transfer theory of Prandtl, the vorticity transfer theory of Taylor, and the similarity theory of Von Kármán. The primary focus is to examine Von Kármán's theory using modern concepts.
Date:
November 1951
Creator:
Lin, C. C. & Shen, S. F.
System:
The UNT Digital Library
Studies of Von Kármán's Similarity Theory and Its Extension to Compressible Flows: A Similarity Theory for Turbulent Boundary Layer Over a Flat Plate in Compressible Flow
Note presenting a treatment of the problem of turbulent boundary layer over a flat plate in compressible flow. The dissipation term in the energy equation, often neglected, is first carefully studied and found to be of importance. The four main approximations include the turbulence pattern, the boundary-layer growth, the two choices of the length scale, and the effect of pressure gradient.
Date:
November 1951
Creator:
Lin, C. C. & Shen, S. F.
System:
The UNT Digital Library
Studies of Von Kármán's Similarity Theory and Its Extension to Compressible Flow: Investigation of Turbulent Boundary Layer Over a Flat Plate in Compressible Flow by the Similarity Theory
Note presenting an investigation of the turbulent-boundary-layer flow over a flat plate in compressible flow. The report shows how the influence of the Mach number can be predicted from the theory after the constant coefficients in the theory are determined by one set of experimental measurements. By averaging the Navier-Stokes equations, differential equations for the mean flow are obtained.
Date:
November 1951
Creator:
Shen, S. F.
System:
The UNT Digital Library
Application of Variational Methods to Transonic Flows With Shock Waves
Note presenting a modification of certain variational methods for the approximate solution of subsonic and transonic flows to compensate for the fact that those methods fail as soon as shock waves occur. By applying a variational principle to the regions of flow behind shock waves and Bateman's original principle to the other regions in the fluid, shock equations can be directly obtained.
Date:
November 1951
Creator:
Wang, Chi-Teh & Chou, Pei-Chi
System:
The UNT Digital Library
Hydrodynamic Investigation of a Series of Hull Models Suitable for Small Flying Boats and Amphibians
Note presenting the results of an investigation to obtain hydrodynamic information on a series of hull models suitable for small flying boats or amphibians of from 2000 to 5000 pounds gross weight. The series of hulls consisted of a basic hull with simple lines, and of plus and minus variations to the design in which the beam, stern-post angle, and afterbody length were altered. The results show that it is possible to design a hull with simple lines that will be suitable for small flying boats or amphibians.
Date:
November 1951
Creator:
Hugli, W. C., Jr. & Axt, W. C.
System:
The UNT Digital Library
Application of Response Function to Calculation of Flutter Characteristics of a Wing Carrying Concentrated Masses
Note presenting concepts involved in the harmonic-response-function method, such as the direct or conjugate characteristic modes, by application of the method to the calculation of the change in flutter characteristics of a wing due to adding concentrated masses.
Date:
November 1951
Creator:
Serbin, H. & Costilow, E. L.
System:
The UNT Digital Library
Flight measurements of drag and base pressure of a fin-stabilized parabolic body of revolution (NACA RM-10) at different Reynolds numbers and at Mach numbers from 0.9 to 3.3
From Summary: "Free-flight tests have been made to investigate the total drag and base drag at different Reynolds numbers of full-scale and half-scale models of an NACA research model designated the RM-10. The general shape of the body was a parabola of revolution of fineness ratio 12.2 with a blunt base to provide space for the rocket jet. The models were stabilized by four 60 degree sweptback fins mounted at the base of the bodies."
Date:
November 1954
Creator:
Jackson, H. Herbert; Rumsey, Charles B. & Chauvin, Leo T.
System:
The UNT Digital Library
Viscosity Corrections to Cone Probes on Rarefied Supersonic Flow at a Nominal Mach Number of 4
Note presenting data obtained for the viscosity corrections to cone probes in supersonic rarefied air flow at a nominal Mach number of 4. The test models consisted of a set of seven geometrically similar 5 degree semivertex-angle cones. Results regarding cone surface pressure distributions, calibration data for geometrically similar cones, orifices size effect, and tests at other Mach numbers are provided.
Date:
November 1954
Creator:
Talbot, L.
System:
The UNT Digital Library
Experimental investigation of notch-size effects on rotating-beam fatigue behavior of 75S-T6 aluminum alloy
Report presenting an investigation to study the influence of size, particularly notch-size effect, on extruded 75S-T6 aluminum-alloy test specimens under rotating bending. Results regarding fatigue strength and fatigue-notch factor are provided.
Date:
November 1954
Creator:
Hyler, W. S.; Lewis, R. A. & Grover, H. J.
System:
The UNT Digital Library
Tensile and compressive stress-strain properties of some high-strength sheet alloys at elevated temperatures
Report presenting the results of tensile and compressive stress-strain tests at temperatures up to 1200 degrees Fahrenheit for SAE 4340, Hy-Tuf, Stainless W, and Inconel X sheet materials which were heat treated to provide ultimate tensile strengths at room temperatures. Tensile and compressive stress-strain curves are given for each material at test temperatures.
Date:
November 1954
Creator:
Hughes, Philip J.; Inge, John E. & Prosser, Stanley B.
System:
The UNT Digital Library
A comparative examination of some measurements of airfoil section lift and drag at supercritical speeds
Report presenting a study of the lift and drag characteristics of a number of airfoil sections at supercritical Mach numbers as determined from wind-tunnel tests.
Date:
November 1952
Creator:
Nitzberg, Gerald E. & Crandall, Stewart M.
System:
The UNT Digital Library
A Theoretical Investigation of the Effect of Partial Wing Lift of Hydrodynamic Landing Characteristics of V-Bottom Seaplanes in Step Impacts
A theoretical investigation is made of the loads and motions in water-landing impacts of wide prismatic V-bottom seaplanes for constant partial wing-lift conditions where the resultant velocity of the seaplane is normal to the keel. An approximate method is given for applying the results of this investigation to the more general case of oblique impact. The increase in vertical hydrodynamic load factor due to wing-lift reduction is shown to be approximately 133 percent of the decrease in air load.
Date:
November 1952
Creator:
Sims, Joseph L. & Schnitzer, Emanuel
System:
The UNT Digital Library
Water-Pressure Distribution During Landings of a Prismatic Model Having an Angle of Dead Rise of 22 1/2 Degrees and Beam-Loading Coefficients of 0.48 and 0.97
Note presenting smooth-water landing tests of a prismatic model with an angle of dead rise of 22.5 degrees as part of a landing investigation being conducted in the impact basin to determine the distribution of water pressure on seaplanes. Landings were made for a variety of beam-loading coefficients, fixed trims, and range of initial flight-path angles. The experimental wave rise, peak pressures, and pressure distributions are found to be in fair agreement with the predictions of the available theory, but better arrangement is obtained by modification of the theory.
Date:
November 1952
Creator:
Smiley, Robert F.
System:
The UNT Digital Library
Effect of high-lift devices on the static-lateral-stability derivatives of a 45 degree sweptback wing of aspect ratio 4.0 and taper ratio 0.6 in combination with a body
Report presenting an investigation in the stability tunnel to determine the effect of high-lift devices on the low-speed static-lateral-stability derivatives of a 45 degree sweptback wing of aspect ratio 4.0 and taper ratio 0.6. Comparisons between the increments in the static-lateral-stability derivatives due to flap deflection obtained from experiment and the increments evaluated by a single sweep theory is also made. Results regarding the presentation of results, longitudinal stability characteristics, static lateral stability characteristics, and comparison of calculated and measured values are provided.
Date:
November 1952
Creator:
Lichtenstein, Jacob H. & Williams, James L.
System:
The UNT Digital Library
A Theoretical and Experimental Investigation of the Effects of Yaw on Pressures, Forces, and Moments During Seaplane Landings and Planing
A theory for the side force, rolling moment, yawing moment, and pressure distribution during yawed landings and planing of seaplanes was developed. For the special case of the straight-sided wedge without chine immersion, the results of the theoretical analysis are presented in the form of generalized curves covering all step landing conditions. Experimental impact and planing data are presented for a prismatic wedge having an angle of dead rise of 22.5 degrees and are shown to be in reasonable agreement with the theoretical predictions.
Date:
November 1952
Creator:
Smiley, Robert F.
System:
The UNT Digital Library
Auxiliary equipment and techniques for adapting the constant-temperature hot-wire anemometer to specific problems in air-flow measurements
Report presenting the constant-temperature hot-wire anemometer amplifier and accessories have been developed to provide an instrument with wide frequency response, good stability, and ease of operation. Techniques are described using the equipment to study periodic phenomena such as surge, rotating stall, and wake surveys in centrifugal- and axial-flow compressors.
Date:
November 1952
Creator:
Laurence, James C. & Landes, L. Gene
System:
The UNT Digital Library
Second Approximation to Laminar Compressible Boundary Layer on Flat Plate in Slip Flow
Note presenting the first-order solution for the laminar compressible boundary-layer flow over a flat plate at constant wall temperature. The effect of slip at the wall as well as the interaction between the boundary-layer flow and the outer stream flow are taken into consideration.
Date:
November 1952
Creator:
Maslen, Stephen H.
System:
The UNT Digital Library