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The numerical solution of compressible fluid flow problems
Numerical methods have been developed for obtaining the steady, adiabatic flow field of a frictionless, perfect gas about arbitrary two-dimensional bodies. The solutions include the subsonic velocity regions, the supersonic velocity regions, and the transition compression shocks, if required. Furthermore, the rotational motion and entropy changes following shocks are taken into account. Extensive use is made of the relaxation method. In this report the details of the methods of solution are emphasized so as to permit others to solve similar problems. Solutions already obtained are mentioned only by way of illustrating the possibilities of the methods described. The methods can be applied directly to wind tunnel and free air tests of arbitrary airfoil shapes at subsonic, sonic, and supersonic speeds.
Date:
May 1944
Creator:
Emmons, Howard W.
System:
The UNT Digital Library
Guides for preventing buckling in axial fatigue tests of thin sheet-metal specimens
From Summary: "Guide fixtures are described by means of which axial fatigue loads including compression may be applied to a thin sheet-metal specimen. Tests indicate that the guides prevented buckling without bypassing the load or injuring the specimen."
Date:
April 1944
Creator:
Brueggeman, W. C. & Mayer, M., Jr.
System:
The UNT Digital Library
Tensile Tests of Round-Head, Flat-Head, and Brazier-Head Rivets
An investigation was conducted to determine the tensile strength of round-head (AN43C), flat-head(AN442), and brazier-head (AN4556) aluminum-alloy rivets because of the scarcity of information on the tensile strength of rivets. The results of the investigation are presented as curves that show the variation of the ratio of the tensile strength of the rivet to the tensile strength of the rivet crank with the ratio of the sheet thickness to the rivet diameter for the different types of rivet.
Date:
March 1944
Creator:
Schuette, Evan H.; Bartone, Leonard M. & Mandel, Merven W.
System:
The UNT Digital Library
Charts for rapid analysis of 45 degree strain-rosette data
From Summary: "Charts are presented for rapidly determining the principal strains and stresses, the maximum shear strain and stress, and the orientation of principal axes from data on 45 degree strain rosettes. The charts may be used for analyzing the conventional data consisting of strains measured along three gage lines 45 degrees apart, but their application is more direct if the rosette data are obtained by means of special circuits that require the use of four gages 45 degrees apart."
Date:
May 1944
Creator:
Manson, S. S.
System:
The UNT Digital Library
An automatic electrical analyzer for 45 degree strain-rosette data
Report presenting a device that automatically analyses the data from a 45 degree strain rosette. The rosette strains are properly combined by means of an electric circuit to yield a direct meter reading of maximum shear strain and major and minor principal strains.
Date:
May 1944
Creator:
Manson, S. S.
System:
The UNT Digital Library
The Shear of Aluminum Alloy Driven Rivets as Affected by Increasing D/T Ratios
"A decrease in shear strengths for increasing D/t ratios was shown in a previous investigation of protruding-head aluminum alloy rivets in double shear conducted at Aluminum Research Laboratories in 1942. Since single shear joints are more common than double shear joints, it was desirable to extend the investigation to single shear joints. This reports describes the results of this investigation of single shear joints and also includes the results of the previous investigation on double shear joints" (p. 1).
Date:
July 1944
Creator:
Hartman, E. C. & Wescoat, C.
System:
The UNT Digital Library
Nondestructive Test Methods for Spot Welds in Aluminum Alloys
Note presenting the results of a study and research investigation of nondestructive test methods for spot welds in aluminum-alloy sheets. The purpose of the research was to investigate proposed nondestructive test methods for spot welds in aluminum alloys, to determine the feasibility of the tests, and to recommend the research methods found suitable for development and reduction to practical application.
Date:
November 1944
Creator:
McMaster, R. C.; Manildi, J. F. & Woolsey, C. C.
System:
The UNT Digital Library
On the General Theory of Thin Airfoils for Nonuniform Motion
"General thin-airfoil theory for a compressible fluid is formulated as boundary problem for the velocity potential, without recourse to the theory of vortex motion. On the basis of this formulation the integral equation of lifting-surface theory for an incompressible fluid is derived with the chordwise component of the fluid velocity at the airfoil as the function to be determined. It is shown how by integration by parts this integral equation can be transformed into the Biot-Savart theorem" (p. 1).
Date:
August 1944
Creator:
Reissner, Eric
System:
The UNT Digital Library
Normal Pressure Tests on Unstiffened Flat Plates
"Flat sheet panels of aluminum alloy (all 17S-T except for two specimens of 24S-T) were tested under normal pressures with clamped edge supports in the structures laboratory of the Guggenheim Aeronautical Laboratory, California Institute of Technology. The thicknesses used ranged from 0.010 to 0.080 inch; the panel sizes ranged from 10 by 10 inches to 10 by 40 inches; and the pressure range was from 0 to 60-pounds-per-square-inch gage. Deflection patterns were measured and maximum tensile strains in the center of the panel were determined by electric strain gages" (p. 1).
Date:
September 1944
Creator:
Head, Richard M. & Sechler, Ernest J.
System:
The UNT Digital Library
Effect of Curvature on Strength of Axially Loaded Sheet-Stringer Panels
Note presenting compressive testing made on twenty-one 24S-T aluminum-alloy sheet-stringer panels 12 inches in length and 16 inches in developed width, reinforced by four Z stringers spaced 4 inches apart. Results regarding strains, buckling, and failure are provided.
Date:
August 1944
Creator:
Ramberg, Walter; Levy, Samuel & Fienup, Kenneth L.
System:
The UNT Digital Library
Studies of Blade Shank and Pitch Distribution for Constant-Speed Propellers
Note presenting an experimental investigation of the influences of blade shank form and pitch distribution on the aerodynamic characteristics of constant-speed propellers. The results indicated that the replacement of round blade shanks by faired ones produced substantial improvements of efficiency which increased with the advance ratio. Results regarding blade shank form, pitch distribution, and influences of blade loading and number of blades are provided.
Date:
January 1945
Creator:
Reid, Elliott G.
System:
The UNT Digital Library
Simply Supported Long Rectangular Plate Under Combined Axial Load and Normal Pressure
Note presenting a solution for the load-strain curve of a simply supported rectangular plate with a width-length ratio of 1:4 under combined normal pressure and axial load. The results indicate it to be conservative design in the elastic range to neglect the effect of lateral pressure on the sheet buckling load and on the load carried by the sheet after buckling.
Date:
October 1944
Creator:
Levy, Samuel; Goldenberg, Daniel & Zibritosky, George
System:
The UNT Digital Library
Artificial Aging of Riveted Joints Made in Alclad 24S-T Sheet Using A17S-T, 17S-T, and 24S-T Rivets
Note presenting an investigation of the effect of artificial aging on the strengths of driven rivets of the alloys used commercially for rivets: specifically, A17S-T, 17S-T, and 24S-T. The change in shear strength for each type of rivet after being exposed to artificial aging treatment of 10 hours at 375 degrees Fahrenheit applied to the driven rivets is described.
Date:
September 1944
Creator:
Zamboky, A. N.
System:
The UNT Digital Library
The inward bulge type buckling of monocoque cylinders 3: revised theory which considers the shear strain energy
Report presenting the third part of an investigation dealing with the inward bulge type buckling of monocoque cylinders the theory of buckling in pure bending, which is refined through the consideration of the shear strain energy stored in the sheet covering, the assumption of a revised deflected shape of the rings, and the use of summations in place of some of the integrations of the preceding report.
Date:
April 1945
Creator:
Hoff, N. J. & Klein, Bertram
System:
The UNT Digital Library
On a Method of Constructing Two-Dimensional Subsonic Compressible Flows Around Closed Profiles
Note showing that under certain conditions, a two-dimensional subsonic compressible flow around an airfoil profile can be derived from an incompressible flow around another profile. The connection between the two "conjugate flows" is given by a simple conformal transformation of the respective hodograph planes.
Date:
March 1945
Creator:
Bers, Lipman
System:
The UNT Digital Library
On Two-Dimensional Flows of Compressible Fluids
"This report is devoted to the study of two-dimensional steady motion of a compressible fluid. It is shown that the complete flow pattern around a closed obstacle cannot be obtained by the method of Chaplygin. In order to overcome this difficulty, a formula for the stream-function of a two-dimensional subsonic flow is derived" (p. 1).
Date:
August 1945
Creator:
Bergman, Stefan
System:
The UNT Digital Library
Shear Elastic Properties of Some High Strength Nonferrous Metals as Affected by Plastic Deformation and by Heat Treatment
Note presenting a study of the shear elastic properties of monel, nickel, Inconel, and aluminum-model tubing, as influenced by extension of annealed specimens, by cold reduction during manufacture, and by stress-relief annealing of cold-reduced materials. With slight extension of annealed tubing, the shear proof stresses generally decrease, owing to induced internal stress.
Date:
January 1945
Creator:
Mebs, R. W. & McAdam, D. J., Jr.
System:
The UNT Digital Library
On the Circulatory Subsonic Flow of a Compressible Fluid Past a Circular Cylinder
"The circulatory subsonic flow around an infinite circular cylinder is computed using the linearized pressure-volume relation, by a method developed in a previous report. Formulas and graphs are given for the velocity and pressure distributions, the circulation, the lift, and the dependence of the critical Mach number upon the position of the stagnation point" (p. 1).
Date:
July 1945
Creator:
Bers, Lipman
System:
The UNT Digital Library
The Elastic Constants for Wrought Aluminum Alloys
"There are several constants which have been devised as numerical representations of the behavior of metals under the action of loadings which stress the metal within the range of elastic action. Some of these constants, such as Young's modulus of elasticity in tension and compression, shearing modulus of elasticity, and Poisson's ratio, are regularly used in engineering calculations. Precise tests and experience indicate that these elastic constants are practically unaffected by many of the factors which influence the other mechanical properties of materials and that a few careful determinations under properly controlled conditions are more useful and reliable than many determinations made under less favorable conditions" (p. 1).
Date:
January 1945
Creator:
Templin, R. L. & Hartmann, E. C.
System:
The UNT Digital Library
Graphical and Analytical Methods for the Determination of a Flow of a Compressible Fluid Around an Obstacle
"Chaplygin introduced the hodograph method in the theory of compressible fluid flows and developed a method for constructing stream functions of such flows. This method, which has been extensively used in investigation of compressible fluid flows, is limited in certain respects. The expression for the stream function obtained in this manner can represent only certain types of flow patterns. In general, flow patterns obtained in this way cannot represent the whole flow around an obstacle, but only a part of such a flow, and therefore several expressions are needed in order to obtain the whole flow" (p. 1).
Date:
July 1945
Creator:
Bergman, Stefan
System:
The UNT Digital Library
Strength of Wing Beams Under Axial and Transverse Loads
Note presenting wing beams tested under axial compressive loads, transverse loads, and combined axial and transverse loads. Deflections and strains in the elastic range were in general agreement with those computed from the simple beam theory after taking account of the secondary bending moment produced by the axial load as the beam deflected under load.
Date:
September 1945
Creator:
Ramberg, Walter; McPherson, A. E. & Levy, Samuel
System:
The UNT Digital Library
Survey of Adhesives and Adhesion
Report presenting an investigation regarding the strengths of bonds between different chemical types of adhesives and adherends. Some of the topics explored include the theoretical aspects of adhesion and properties of adhesively bonded structures.
Date:
August 1945
Creator:
Rinker, R. C. & Kline, G. M.
System:
The UNT Digital Library
Two-Dimensional Irrotational Mixed Subsonic and Supersonic Flow of a Compressible Fluid and the Upper Critical Mach Number
Note presenting the use of the hodograph method to investigate the problem of flow of a compressible fluid past a body with subsonic flow at infinity. Explicit formulas for numerical calculations are given for the flow about a body, such as an elliptical cylinder, and for the periodic flow such as would exist over a wavy surface.
Date:
May 1946
Creator:
Tsien, Hsue-Shen & Kuo, Yung-Huai
System:
The UNT Digital Library
Net Heat of Combustion of AN-F-28 Aviation Gasolines
"Experimental data on the heats of combustion and hydrogen contents of a number of aviation gasolines have been used in deriving a formula for computing net heat of combustion from (measured) gross heat of combustion. This formula appears to be sufficiently reliable for the purpose and has the advantage of making hydrogen determinations unnecessary. The data on heats of combustion are presented in tabular form, and in graphs showing the relation between net heat of combustion and (1) hydrogen content, (2) aniline point, (3) APO gravity, and (4) the product of aniline point and APO gravity" (p. 1).
Date:
June 1945
Creator:
Jessup, R. S. & Cragoe, C. S.
System:
The UNT Digital Library