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Practical Calculation of Second-Order Supersonic Flow Past Nonlifting Bodies of Revolution
"Calculation of second-order supersonic flow past bodies of revolution at zero angle of attack is described in detail, and reduced to routine computation. Use of an approximate tangency condition is shown to increase the accuracy for bodies with corners. Tables of basic functions and standard computing forms are presented. The procedure is summarized so that one can apply it without necessarily understanding the details of the theory" (p. 1).
Date:
July 1952
Creator:
Van Dyke, Milton D.
System:
The UNT Digital Library
Influence of Chemical Composition on Rupture Test Properties at 1500 Degrees Fahrenheit of Forged Chromium-Cobalt-Nickel-Iron Base Alloys
Note presenting an investigation of the influence of systematic variations of chemical composition on rupture properties at 1500 degrees Fahrenheit for 62 modifications of a basic alloy. All of the elements in the alloy can be varied individually between quite wide limits without significantly changing the rupture properties. Results regarding carbon, nitrogen, manganese, silicon, chromium, nickel, cobalt, molybdenum, tungsten, and columbium are provided.
Date:
July 1952
Creator:
Freeman, J. W.; Ewing, J. F. & White, A. E.
System:
The UNT Digital Library
Bending With Large Deflection of a Clamped Rectangular Plate With Length-Width Ratio of 1.5 Under Normal Pressure
"The Von Karman equations for a thin flat plate with large deflections are solved for the special case of a plate with clamped edges having a ratio of length to width of 1.5 and loaded by uniform normal pressure. Center deflections, membrane stresses, and extreme-fiber bending stresses are given as a function of pressure for center deflections up to twice the thickness of the plate. For small deflections the results coincide with those obtained by Hencky from the linear theory" (p. 1).
Date:
July 1942
Creator:
Levy, Samuel & Greenman, Samuel
System:
The UNT Digital Library
Effects of airplane flexibility on wing bending strains in rough air
"Some results on the effects of wing flexibility on wing bending strains as determined from flight tests of a Boeing B-29 and a Boeing B-47A airplane in rough air are presented. Results from an analytical study of the flexibility effects on the B-29 wing strains are compared with the experimental results. Both the experimental and calculated results are presented as frequency-response functions of the bending strains at various spanwise wing stations to gust disturbances. In addition, some indirect evidence of the effect of spanwise variations in turbulence on the response of the B-47A airplane is presented" (p. 1).
Date:
July 1957
Creator:
Coleman, Thomas L.; Press, Harry & Shufflebarger, C. C.
System:
The UNT Digital Library
Behavior of materials under conditions of thermal stress
Report presenting a review of available information on the behavior of brittle and ductile materials under conditions of thermal stress and thermal shock. A number of practical methods that have been used to minimize the negative effects of thermal stress and shock are provided.
Date:
July 1953
Creator:
Manson, S. S.
System:
The UNT Digital Library
Some Investigations of the General Instability of Stiffened Metal Cylinders 1: Review of Theory and Bibliography
This is the first of a series of reports covering an investigation of the general instability problem. This report consists of earlier reports along with the results of the current studies in the form of a series of reports covering the entire investigation.
Date:
July 1943
Creator:
unknown
System:
The UNT Digital Library
Vibration survey of four representative types of air-cooled turbine blades
Report presenting an investigation conducted in a turbojet engine mounted in a sea-level test stand to determine the vibrational characteristics of four representative types of air-cooled turbine blades.Two were standard-span blades and two were long-span blades for high mass-flow turbines. Results regarding the coolant-flow rate, vibratory stresses, vibrational characteristics, and failures are provided.
Date:
July 1958
Creator:
Calvert, Howard F. & Smith, Gordon T.
System:
The UNT Digital Library
Studies of structural failure due to acoustic loading
A discussion of the acoustic fatigue problem of aircraft structures along with data pertaining to the acoustic inputs from some power plants in common use. Comparisons are given for results of fatigue tests of flat panels and cantilever beams exposed to random- and discrete-type inputs. Both the stress level of the test and type of model are significant, so no generalizations can be made at this time.
Date:
July 1957
Creator:
Hess, Robert W.; Fralich, Robert W. & Hubbard, Harvey H.
System:
The UNT Digital Library
Impingement of water droplets on wedges and diamond airfoils at supersonic speeds
"An analytical solution has been obtained for the equations of motion of water droplets impinging on a wedge in a two-dimensional supersonic flow field with a shock wave attached to the wedge. The closed-form solution yields analytical expressions for the equation of the droplet trajectory, the local rate of impingement and the impingement velocity at any point on the wedge surface, and the total rate of impingement. The analytical expressions are utilized to determine the impingement on the forward surfaces of diamond airfoils in supersonic flow fields with attached shock waves" (p. 1).
Date:
July 1953
Creator:
Serafini, John S.
System:
The UNT Digital Library
Theoretical pressure distribution and wave drags for conical boattails
"Afterbody pressure distributions and wave drag were calculated using a second-order theory for a variety of conical boattails at zero angle of attack. Results are presented for Mach numbers from 1.5 to 4.5, area ratios from 0.200 to 0.800, and boattail angle from 3 degrees to 11 degrees. The results indicate that for a given boattail angle, the wave drag decreases with increasing Mach number and area ratio" (p. 1).
Date:
July 1953
Creator:
Jack, John R.
System:
The UNT Digital Library
Effect of prestraining of recrystallization temperature and mechanical properties of commercial, sintered, wrought molybdenum
Given three presumably identical lots of commercial, sintered, wrought molybdenum, the 1-hour recrystallization temperature of one lot remained above 2900 F by limiting the amount of effective restraining to 35 percent or less. Different recrystallization temperatures were obtained in various atmospheres, the highest in argon and the lowest in hydrogen. Metal thus fabricated and then stress-relieved possessed an ultimate tensile strength at room temperature within 10 percent of metal swaged 99 percent and also possessed equivalent ductility. At 1800 F, equivalent strength and ductility was obtained irrespective of the amount of swaging over the range of 10 to 99 percent.
Date:
July 1953
Creator:
Dike, Kenneth C. & Long, Roger A.
System:
The UNT Digital Library
A comparative study of weights and sizes of flat-plate exhaust-gas-to-air heat exchangers with and without fins
Note presenting analytical comparisons of weights and volumes for flat-plate heat exchangers with the same calculated thermal output and friction pressure drop for three different fin configurations, including no fins, fins in both the air and exhaust gas passages, and fins in the air passages only. Two different heat exchangers were used and compared with predicted weights and volumes.
Date:
July 1947
Creator:
Tendeland, Thorval & Steinmetz, Charles P.
System:
The UNT Digital Library
Ground Effects on the Longitudinal Characteristics of Two Models With Wings Having Low Aspect Ratio and Pointed Tips
Wind-tunnel tests were conducted to determine the ground effects on a tailless model with a wing of aspect ratio 2 and infinite taper, and on a tailed model with a triangular wing of aspect ratio 3, with flaps. Control-surface hinge moments were measured on the tailless model. The results are compared with the predictions of the theory of Tani, et al.
Date:
July 1957
Creator:
Buell, Donald A. & Tinling, Bruce E.
System:
The UNT Digital Library
Preview of Behavior of Grain Boundaries in Creep of Aluminum Bicrystals
Note presenting testing of the gliding of one metal crystal with respect to another, along their mutual grain boundary, during high-temperature creep tests conducted with bicrystals of pure aluminum. Stresses of from 1 to 100 psi and temperatures from 200 to 650 degrees Celsius were employed. Results regarding grain boundary glide rate, influence of orientation difference between grains, influence of temperature, influence of applied stress, structure of the operated grain boundary, and structural changes within grains are provided.
Date:
July 1952
Creator:
Rhines, F. N. & Cochardt, A. W.
System:
The UNT Digital Library
Propellant vaporization as a criterion for rocket engine design; Calculations of chamber length to vaporize a single n-heptane drop
Report presenting an analysis based on droplet-evaporation theory, which shows that for a given combustor length, the percent of fuel mass vaporized can be increased by decreasing the fuel-drop size and initial drop velocity, or by increasing chamber pressure, final gas velocity, and initial fuel temperature. The results were correlated to give a single curve of percent of fuel evaporated as a function of the chamber length and the factors involving the parameters.
Date:
July 1957
Creator:
Priem, Richard J.
System:
The UNT Digital Library
Internal characteristics and performance of an aerodynamically controlled, variable-discharge convergent nozzle
Report presenting a study in which the effective flow area of a convergent exhaust nozzle was reduced by injecting a high-pressure secondary jet into the nozzle near the exit. Analytical expressions relating the performance with significant design and operating variables were developed. Some of the configurations, altered to operate as jet deflectors, produced significant values of side force but also operated at reduced effective flow area.
Date:
July 1958
Creator:
McArdle, Jack G.
System:
The UNT Digital Library
Effect of favorable pressure gradients on transition for several bodies of revolution at Mach 3.12
Report presenting experimental results relating to the effect of pressure gradient on the location of transition for several constant-pressure-gradient models an two power-profile models. Results regarding the local flow conditions, recovery-factor distributions, effect of unit Reynolds number, and effect of pressure gradient are provided.
Date:
July 1958
Creator:
Jack, John R.
System:
The UNT Digital Library
Measurements of flying qualities of an F-47D-30 airplane to determine lateral and directional stability and control characteristics
Report presenting flight tests to determine the lateral and directional stability and control characteristics of an F-47D-30 airplane. Results regarding the physical characteristics, static directional and lateral stability and control characteristics, dynamic directional stability and control characteristics, directional and lateral trim characteristics, and aileron control characteristics are provided.
Date:
July 1952
Creator:
Goranson, R. Fabian & Kraft, Christopher C., Jr.
System:
The UNT Digital Library
Experimental Investigation of Attenuation of Strong Shock Waves in a Shock Tube With Hydrogen and Helium as Driver Gases
Note presenting an experimental investigation of the attenuation of strong shock waves in air in a shock tube. Time-history measurements were made of the static pressure at several stations in the wall of the tube. Hydrogen and helium were used as driver gases. A helium-driven shock wave was found to decay only about one-half as rapidly as a hydrogen-driven shock wave.
Date:
July 1957
Creator:
Jones, Jim J.
System:
The UNT Digital Library
Dynamic stability of vehicles traversing ascending or descending paths through the atmosphere
From Summary: "An analysis is given of the oscillatory motions of vehicles which traverse ascending and descending paths through the atmosphere at high speed. The specific case of a skip path is examined in detail, and this leads to a form of solution for the oscillatory motion which should recur over any trajectory. The distinguishing feature of this form is the appearance of the Bessel rather than the trigonometric function as the characteristic mode of oscillation."
Date:
July 1958
Creator:
Tobak, Murray & Allen, H. Julian
System:
The UNT Digital Library
Experimental stress analysis of stiffened cylinders with cutouts: Shear load
A cylindrical semimonocoque shell of circular cross section was mounted as a cantilever and loaded by a direct shear at the tip. The cylinder was tested with no cutout, with a rectangular cutout on the tension side, and with the cutout centered on the neutral axis on one side of the cylinder. The cutout was successively enlarged through six sizes varying from 30 degrees to 130 degrees in circumference and from 1 and 2 bays in length. Strain measurements were made with resistance-type wire strain gages near the cutout on the stringers, the skin, and the rings for each case, and the stresses obtained are presented in tables. (author).
Date:
July 1954
Creator:
Schlechte, Floyd R. & Rosecrans, Richard
System:
The UNT Digital Library
The minimization of wave drag for wings and bodies with given base area or volume
"The minimization of wave drag for thin aerodynamic shapes carrying no lift is studied for conditions under which either base area or volume is specified. When volume alone is given, the analysis is limited to shapes with straight trailing edges normal to the stream direction. The problem of minimization is reduced to one of finding a two-dimensional harmonic function with known boundary conditions" (p. 1).
Date:
July 1957
Creator:
Heaslet, Max A.
System:
The UNT Digital Library
An evaluation of the effects of flexibility on wing strains in rough air for a large swept-wing airplane by means of experimentally determined frequency-response functions with an assessment of random-process techniques employed
Report presenting power spectral methods of analysis as applied to flight test measurements of the strain responses of a large swept-wing bomber airplane in rough air in order to determine the effects of airplane in rough air in order to determine the effects of airplane structural dynamics on the strain responses.
Date:
July 1958
Creator:
Coleman, Thomas L.; Press, Harry & Meadows, May T.
System:
The UNT Digital Library
Local Instability of the Elements of a Truss-Core Sandwich Plate
The charts presented give the compressive buckling coefficients for a single-truss-core and a double-truss-core sandwich plate. These charts cover a wide range of sandwich proportions and may be used for sandwiches with unequal faces. They apply to inplane compressive loads acting parallel or perpendicular to the core direction or for various combinations of these loads. (author).
Date:
July 1958
Creator:
Anderson, Melvin S.
System:
The UNT Digital Library