Air forces and moments on triangular and related wings with subsonic leading edges oscillating in supersonic potential flow (open access)

Air forces and moments on triangular and related wings with subsonic leading edges oscillating in supersonic potential flow

From Introduction: "This report is concerned with the derivation of expressions for the velocity potential and associated forces and moments for oscillating triangular wings in supersonic flow. The purpose of the present report is to make use of the expanded form of the velocity potential to obtain the forces and moments, based on the first terms of this potential, for a rigid triangular wing performing vertical and pitching sinusoidal oscillations in mixed supersonic flow."
Date: June 19, 1951
Creator: Watkins, Charles E. & Berman, Julian H.
System: The UNT Digital Library
Analysis of thrust augmentation of turbojet engines by water injection at compressor inlet including charts for calculating compression processes with water injection (open access)

Analysis of thrust augmentation of turbojet engines by water injection at compressor inlet including charts for calculating compression processes with water injection

From Summary: "Curves are presented that show the theoretical performance of the augmentation method for various amounts of water injected and the effects of varying flight Mach number, altitude, ambient-air temperature, ambient relative humidity, compressor pressure ratio, and inlet-diffuser efficiency. Numerical examples, illustrating the use of the psychrometric chart and the Mollier diagram in calculating both compressor-inlet and compressor-outlet conditions when water is injected at the compressor inlet, are presented."
Date: June 1, 1950
Creator: Wilcox, E. Clinton & Trout, Arthur M.
System: The UNT Digital Library
Analytical Derivation and Experimental Evaluation of Short-Bearing Approximation for Full Journal Bearing (open access)

Analytical Derivation and Experimental Evaluation of Short-Bearing Approximation for Full Journal Bearing

From Introduction: "This report extends the short-bearing pressure-distribution function of Michell and Cardullo to give equations for the various bearing characteristics. This short-bearing approximation makes available formulas relating eccentricity ratio to applied load, attitude angle, angular position of peak film pressure to unit pressure on projected area."
Date: June 12, 1953
Creator: DuBois, George B. & Ocvirk, Fred W.
System: The UNT Digital Library
Calculated and Measured Stresses in Simple Panels Subject to Intense Random Acoustic Loading Including the Near Noise Field of a Turbojet Engine (open access)

Calculated and Measured Stresses in Simple Panels Subject to Intense Random Acoustic Loading Including the Near Noise Field of a Turbojet Engine

"Flat 2024-T3 aluminum panels measuring 11 inches by 13 inches were tested in the near noise fields of a 4-inch air jet and turbojet engine. The stresses which were developed in the panels are compared with those calculated by generalized harmonic analysis. The calculated and measured stresses were found to be in good agreement. In order to make the stress calculations, supplementary data relating to the transfer characteristics, damping, and static response of flat and curved panels under periodic loading are necessary and were determined experimentally. In addition, an appendix containing detailed data on the near pressure field of the turbojet engine is included" (p. 703).
Date: June 3, 1957
Creator: Lassiter, Leslie W. & Hess, Robert W.
System: The UNT Digital Library
Calculations of Laminar Heat Transfer Around Cylinders of Arbitrary Cross Section and Transpiration-Cooled Walls With Application to Turbine Blade Cooling (open access)

Calculations of Laminar Heat Transfer Around Cylinders of Arbitrary Cross Section and Transpiration-Cooled Walls With Application to Turbine Blade Cooling

"An approximate method for the development of flow and thermal boundary layers in the laminar region on cylinders with arbitrary cross section and transpiration-cooled walls is obtained by the use of Karman's integrated momentum equation and an analogous heat-flow equation. Incompressible flow with constant property values throughout the boundary layer is assumed. The velocity and temperature profiles within the boundary layer are approximated by expressions composed of trigonometric functions" (p. 339).
Date: June 22, 1951
Creator: Eckert, E. R. G. & Livingood, J. N. B.
System: The UNT Digital Library
Comparison of performance of experimental and conventional cage designs and materials for 75-millimeter-bore cylindrical roller bearings at high speed (open access)

Comparison of performance of experimental and conventional cage designs and materials for 75-millimeter-bore cylindrical roller bearings at high speed

From Summary: "The results of two investigations, one to determine the relative merits of four experimental and two conventional design 75-millimeter-bore (size 215) cylindrical roller bearings and one to determine the relative merits of nodular iron and bronze as cage materials for this size and type of bearing, are presented in this report. Nine test bearings were operated over a range of dn values (product of bearing bore in mm and shaft speed in r.p.m) from 0.3 x 10(6) to 2.3 x 20(6), radial loads for 7 to 1613 pounds, and oil flows from 2 to 8 pounds per minute with a single-jet circulatory oil feed. Of the six bearings used to evaluate designs, four were experimental types with outer-race-riding cages and inner-race-guided rollers, and two were conventional types, one with outer-race-guided rollers and cage and one with inner-race-guided rollers and cage."
Date: June 30, 1954
Creator: Anderson, William J.; Macks, E. Fred & Nemeth, Zolton N.
System: The UNT Digital Library
Cooperative Investigation of Relationship Between Static and Fatigue Properties of Wrought N-155 Alloy at Elevated Temperatures (open access)

Cooperative Investigation of Relationship Between Static and Fatigue Properties of Wrought N-155 Alloy at Elevated Temperatures

Report presents the correlation of extensive data obtained relating properties of wrought N-155 alloy under static, combined static and dynamic, and complete reversed dynamic stress conditions. Time period for fracture ranged from 50 to 500 hours at room temperature, 1,000 degrees, 1,200 degrees, and 1,500 degrees F.
Date: June 15, 1953
Creator: NACA Subcommittee on Power-Plant Materials
System: The UNT Digital Library
Diffusion of heat from a line source in isotropic turbulence (open access)

Diffusion of heat from a line source in isotropic turbulence

"An experimental and analytical study has been made of some features of the turbulent heat diffusion behind a line heated wire stretched perpendicular to a flowing isotropic turbulence. The mean temperature distributions have been measured with systematic variations in wind speed, size of turbulence-producing grid, and downstream location of heat source. The nature of the temperature fluctuation field has been studied" (p. 1).
Date: June 5, 1951
Creator: Uberoi, Mahinder S. & Corrsin, Stanley
System: The UNT Digital Library
Direct Measurements of Skin Friction (open access)

Direct Measurements of Skin Friction

"A device has been developed to measure local skin friction on a flat plate by measuring the force exerted upon a very small movable part of the surface of the flat plate. These forces, which range from about 1 milligram to about 100 milligrams, are measured by means of a reactance device. The apparatus was first applied to measurements in the low-speed range, both for laminar and turbulent boundary layers. The device was then applied to high-speed subsonic flow and the turbulent-skin-friction coefficients were determined up to a Mach number of about 0.8" (p. 281).
Date: June 1, 1951
Creator: Dhawan, Satish
System: The UNT Digital Library
Discussion of boundary-layer characteristics near the wall of an axial-flow compressor (open access)

Discussion of boundary-layer characteristics near the wall of an axial-flow compressor

From Summary: "The boundary-layer velocity profiles in the tip region of an axial-flow compressor downstream of the guide vanes and downstream of the rotor were measured by use of total-pressure and claw-type yaw probes. These velocities were resolved into two components: one along the streamline of the flow outside the boundary layer, and the other perpendicular to it. The affinity among all profiles was thus demonstrated with the boundary-layer thickness and the deflection of the boundary layer at the wall as the generalizing parameters. By use of these results and the momentum-integral equations, boundary-layer characteristics on the walls of an axial-flow compressor were qualitatively evaluated."
Date: June 7, 1951
Creator: Mager, Artur; Mahoney, John J. & Budinger, Ray E.
System: The UNT Digital Library
The effects on dynamic lateral stability and control of large artificial variations in the rotary stability derivatives (open access)

The effects on dynamic lateral stability and control of large artificial variations in the rotary stability derivatives

This report presents the results of an investigation conducted in the Langley free-flight tunnel to determine the effects of large artificial variations of several rotary lateral-stability derivatives on the dynamic lateral stability and control characteristics of a 45 degree sweptback-wing airplane model. Calculations of the period and damping of the lateral motions and of the response to roll and yaw disturbances were made for correlation with the experimental results. The calculated results were in qualitative agreement with the experimental results in predicting the general trends in flight characteristics produced by large changes in the stability derivatives, but in some cases the theory with the assumption of zero lag was not in good quantitative agreement with the experimental results.
Date: June 20, 1952
Creator: Schade, Robert O. & Hassell, James L., Jr.
System: The UNT Digital Library
Experimental investigation of free-convection heat transfer in vertical tube at large Grashof numbers (open access)

Experimental investigation of free-convection heat transfer in vertical tube at large Grashof numbers

Report presents the results of an investigation conducted to study free-convection heat transfer in a stationary vertical tube closed at the bottom. The walls of the tube were heated, and heated air in the tube was continuously replaced by fresh cool air at the top. The tube was designed to provide a gravitational field with Grashof numbers of a magnitude comparable with those generated by the centrifugal field in rotating-blade coolant passages (10(8) to 10(13)). Local heat-transfer coefficients in the turbulent-flow range and the temperature field within the fluid were obtained.
Date: June 30, 1952
Creator: Eckert, E. R. G. & Diaguila, A. J.
System: The UNT Digital Library
An experimental investigation of sting-support effects on drag and a comparison with jet effects at transonic speeds (open access)

An experimental investigation of sting-support effects on drag and a comparison with jet effects at transonic speeds

Various dummy stings were tested on the rear of a related series of afterbody shapes for Mach numbers from 0.80 to 1.10 and Reynolds numbers based on body length from 15.0 x 16 to the 6th power to 17.4 x 10 to the 6th power. A method is presented whereby approximate sting interference corrections can be made to models having afterbody shapes and sting supports similar to those of these tests if the Reynolds numbers are of the same order of magnitude and a turbulent boundary layer exists at the model base. Also presented is an analysis of jet duplication by use of a sting.
Date: June 4, 1956
Creator: Cahn, Maurice S.
System: The UNT Digital Library
Experimental investigation of the effect of vertical-tail size and length and of fuselage shape and length on the static lateral stability characteristics of a model with 45 degree sweptback wing and tail surfaces (open access)

Experimental investigation of the effect of vertical-tail size and length and of fuselage shape and length on the static lateral stability characteristics of a model with 45 degree sweptback wing and tail surfaces

An investigation was made to determine the effects of vertical-tail size and length and of fuselage shape and length on the static lateral stability characteristics of a model with wing and vertical tails having the quarter-chord lines swept back 45 degrees. The results indicate that the directional instability of the various isolated fuselages was about two-thirds as large as that predicted by classical theory.
Date: June 5, 1950
Creator: Queijo, M. J. & Wolhart, Walter D.
System: The UNT Digital Library
Generalized Indical Forces on Deforming Rectangular Wings in Supersonic Flight (open access)

Generalized Indical Forces on Deforming Rectangular Wings in Supersonic Flight

"A method is presented for determining the time-dependent flow over a rectangular wing moving with a supersonic forward speed and undergoing small vertical distortions expressible as polynomials involving spanwise and chordwise distances. The solution for the velocity potential is presented in a form analogous to that for steady supersonic flow having the familiar "reflected area" concept discovered by Evvard. Particular attention is paid to indicial-type motions and results are expressed in terms of generalized indicial forces. Numerical results for Mach numbers equal to 1.1 and 1.2 are given for polynomials of the first and fifth degree in the chordwise and spanwise directions, respectively, on a wing having an aspect ratio of 4" (p. 595).
Date: June 30, 1954
Creator: Lomax, Harvard; Fuller, Franklyn B. & Sluder, Loma
System: The UNT Digital Library
High-Resolution Autoradiography (open access)

High-Resolution Autoradiography

This investigation was made to adapt wet-process autoradiography to metallurgical samples to obtain high resolution of segregated radioactive elements in microstructures. Results are confined to development of the technique, which was perfected to a resolution of less than 10 microns. The radioactive samples included carbon-14 carburized iron and steel, nickel-63 electroplated samples, a powder product containing nickel-63, and tungsten-185 in N-155 alloy.
Date: June 1, 1953
Creator: Towe, George C.; Gomberg, Henry J. & Freemen, J. W.
System: The UNT Digital Library
Incompressible Flutter Characteristics of Representative Aircraft Wings (open access)

Incompressible Flutter Characteristics of Representative Aircraft Wings

"This report gives the results of a detailed study of the flutter characteristics of four representative aircraft wings. This study was made using the electric-analog computer at the California Institute of Technology. During the course of this investigation eight important parameters of each wing were varied and, in addition, the effects of mass, inertia, pitching spring, and location of a concentrated mass were investigated for all four wings and at several sweepback angles" (p. 1385).
Date: June 6, 1955
Creator: Wilts, C. H.
System: The UNT Digital Library
Influence of Alloying upon Grain-Boundary Creep (open access)

Influence of Alloying upon Grain-Boundary Creep

"Grain-boundary displacement, occurring in bicrystals during creep at elevated temperature (350 degrees c), has been measured as a function of the copper content (0.1 to 3 percent) in a series of aluminum-rich aluminum-copper solid-solution alloys. The minimums in stress and temperature, below which grain-boundary motion does not occur, increase regularly with the copper content as would be expected if recovery is necessary for movement. Otherwise, the effects, if any, of the copper solute upon grain-boundary displacement and its rate are too small for identification by the experimental technique employed" (p. 1).
Date: June 24, 1955
Creator: Rhines, F. N.; Bond, W. E. & Kissel, M. A.
System: The UNT Digital Library
The Mechanism of Thermal-Gradient Mass Transfer in the Sodium Hydroxide-Nickel System (open access)

The Mechanism of Thermal-Gradient Mass Transfer in the Sodium Hydroxide-Nickel System

"Thermal-gradient mass transfer" was investigated in the molten sodium hydroxide-nickel system. Possible mechanisms (physical, electrochemical, and chemical) are discussed in terms of experimental and theoretical evidence. Experimental details are included in appendixes.
Date: June 20, 1957
Creator: May, Charles E.
System: The UNT Digital Library
A Method of Computing the Transient Temperature of Thick Walls From Arbitrary Variation of Adiabatic-Wall Temperature and Heat-Transfer Coefficient (open access)

A Method of Computing the Transient Temperature of Thick Walls From Arbitrary Variation of Adiabatic-Wall Temperature and Heat-Transfer Coefficient

"A method of calculating the temperature of thick walls has been developed in which the time series and the response to a unit triangle variation of surface temperature concepts are used, together with essentially standard formulas for transient temperature and heat flow into thick walls. The method can be used without knowledge of the mathematical tools of its development. The method is particularly suitable for determining the wall temperature in one-dimensional thermal problems in aeronautics where there is a continuous variation of the heat-transfer coefficient and adiabatic-wall temperature" (p. 877).
Date: June 18, 1957
Creator: Hill, P. R.
System: The UNT Digital Library
NACA Transonic Wind-Tunnel Test Sections (open access)

NACA Transonic Wind-Tunnel Test Sections

Report presents an approximate subsonic theory for the solid-blockage interference in circular wind tunnels with walls slotted in the direction of flow. This theory indicated the possibility of obtaining zero blockage interference. Tests in a circular slotted tunnel based on the theory confirmed the theoretical predictions.
Date: June 20, 1955
Creator: Wright, Ray H. & Ward, Vernon G.
System: The UNT Digital Library
On boattail bodies of revolution having minimum wave drag (open access)

On boattail bodies of revolution having minimum wave drag

The problem of determining the shape of slender boattail bodies of revolution for minimum wave drag has been reexamined. It was found that minimum solutions for Ward's slender-body drag equation can exist only for the restricted class of bodies for which the rate of change of cross-sectional area at the base is zero. In order to eliminate this restriction, certain higher order terms must be retained in the drag equation and isoperimetric relations. The minimum problem for the isoperimetric conditions of given length, volume, and base area is treated as an example. According to Ward's drag equation, the resulting body shapes have slightly less drag than those determined by previous investigators.
Date: June 8, 1955
Creator: Harder, Keith C. & Rennemann, Conrad, Jr.
System: The UNT Digital Library
Shock-turbulence interaction and the generation of noise (open access)

Shock-turbulence interaction and the generation of noise

Interaction of convected field of turbulence with shock wave is analyzed to yield modified turbulence, entropy spottiness, and noise generated downstream of the shock. Analysis is generalization of single-spectrum-wave treatment of NACA-TN-2864. Formulas for spectra and correlations are obtained. Numerical calculations yield curves of rms velocity components, temperature, pressure, and noise in db against Mach number for m = 1 to infinity; both isotropic and strongly axisymmetric (lateral/longitudinal = 36/1) initial turbulence are treated. In either case, turbulence of 0.1 percent longitudinal component generates about 120 dbs of noise.
Date: June 3, 1954
Creator: Ribner, H. S.
System: The UNT Digital Library
The similarity law for hypersonic flow and requirements for dynamic similarity of related bodies in free flight (open access)

The similarity law for hypersonic flow and requirements for dynamic similarity of related bodies in free flight

The similarity law for nonsteady, inviscid, hypersonic flow about slender three-dimensional shapes is derived. Conclusions drawn are shown to be valid for rotational flow. Requirements for dynamic similarity of related shapes in free flight are obtained. The law is examined for steady flow about related three-dimensional shapes. Results of an experimental investigation of the pressures acting on two inclined cones are found to check the law as it applies to bodies of revolution.
Date: June 5, 1951
Creator: Hamaker, Frank M.; Neice, Stanford E. & Wong, Thomas J.
System: The UNT Digital Library