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Some Recent Contributions to the Study of Transition and Turbulent Boundary Layers

Description: Report presenting a paper in two parts about transition and turbulent boundary layers. The first part reviews the current problem of the instability of laminar boundary layers. The second part reviews the current state of knowledge of the mechanics of turbulent boundary layers and of the methods now being used for fundamental studies of the turbulent fluctuations in turbulent boundary layers.
Date: April 1947
Creator: Dryden, Hugh L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Analysis of Static Aeroelastic Behavior of Low-Aspect-Ratio Rectangular Wings

Description: "Slender-body theory is used in conjunction with late theory to analyze the static aeroelastic-divergence behavior of low-aspect-ratio rectangular wings of constant thickness when chordwise deformations are considered. In the analysis, the spanwise variation of the deflection is restricted to a parabola but the chordwise variation is allowed complete freedom. Results show the variation of the divergence speed and mode shape with the aspect ratio" (p. 1).
Date: April 1957
Creator: Hedgepeth, John M. & Waner, Paul G., Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Expected numbers of maxima and minima of a stationary random process with non-Gaussian frequency distribution

Description: Report presenting a method for calculating the expected number of maxima or minima of a random process with non-Gaussian frequency distribution from the statistical moments of the process and its first two derivatives. The effects of skewness and kurtosis can also be calculated provided the required moments are known.
Date: April 1957
Creator: Diederich, Franklin W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The effect of control stiffness and forward speed on the flutter of a 1/10-scale dynamic model of a two-blade jet-driven helicopter rotor

Description: Report presenting testing of several configurations of rotor blades in order to evaluate the effect of variations in the blade-pitch-control stiffness and forward speed on the flutter speed.
Date: April 1955
Creator: Brooks, George W. & Sylvester, Maurice A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Experimentally determined natural vibration modes of some cantilever-wing flutter models by using an acceleration method

Description: From Summary: "Three-dimensional views are presented of the first three natural vibration mode shapes of ten cantilever-wing models. A table of normalized deflections at six spanwise and five chordwise stations is included for each mode. These mode shapes were measured by a rather unique experimental technique using grains of sand as accelerometers."
Date: April 1957
Creator: Hanson, Perry W. & Tuovila, W. J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A theoretical analysis of the effect of engine angular momentum on longitudinal and directional stability in steady rolling maneuvers

Description: From Summary: "The effect of engine momentum on the longitudinal and directional stability of aircraft in steady rolling maneuvers has been investigated. The results presented indicate that the gyroscopic moments produced on the aircraft by a rotating engine in rolling maneuvers can have an appreciable effect on the range of rolling velocities for which longitudinal or directional instability might occur."
Date: April 1958
Creator: Gates, Ordway B., Jr. & Woodling, C. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Effect of fuselage length and a canopy on the static longitudinal and lateral stability characteristics of 45 degrees sweptback airplane models having fuselages with square cross sections

Description: Report presenting a wind-tunnel investigation at low speed to determine the effects of fuselage nose length and a canopy on the static longitudinal and lateral stability characteristics of a complete model with a fuselage with square cross sections, a 45 degree sweptback wing, and a 45 degree sweptback horizontal tail.
Date: April 1957
Creator: Jaquet, Byron M. & Fletcher, H. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Full-Scale Investigation of Several Jet-Engine Noise-Reduction Nozzles

Description: A number of nozzles which use the mixing interference of adjacent jets for noise suppression were investigated. Reductions in sound power of nearly 70 percent (5 db) with thrust losses of 1 percent were achieved. A method of calculating the limiting frequency affected by this type of suppression nozzle, that is , multiple-slot nozzles, is presented. Data are shown which indicate that further large reductions in sound power are not likely with mixing-interference nozzles.
Date: April 1957
Creator: Coles, Willard D. & Callaghan, Edmund E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Effect of spanwise variations in gust intensity on the lift due to atmospheric turbulence

Description: The effect of spanwise variations in gust intensity on the power spectrum directly due to atmospheric turbulence is calculated for several analytic approximations to the correlation function or power spectra of atmospheric turbulence, for several spanwise weighing functions (span loadings), and for various angles of sweepback.
Date: April 1957
Creator: Diederich, Franklin W. & Drischler, Joseph A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Investigation of the Ni(sub 3)Al Phrase of Nickel-Aluminum Alloys

Description: Note presenting an investigation to determine the effects of homogenization treatments and of composition on the tensile properties of as-cast alloys in the Ni(sub 3)Al-intermetallic-phase region. Results regarding the effects of the casting method, hot-workability of stoichiometric Ni(sub 3)Al, mechanical properties, and microstructure of Ni(sub 3)Al are provided.
Date: April 1956
Creator: Grala, Edward M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Self shielding in rectangular and cylindrical geometries

Description: Report presenting the steady-state diffusion and transport theory solutions of several self-shielding problems for multiregion cells of rectangular and cylindrical geometries. Results regarding the rectangular case and cylindrical case are provided.
Date: April 1956
Creator: Schneider, Harold; Saper, Paul G. & Kadow, Charles F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Static strength of cross-grain 7075-T6 aluminum-alloy extruded bar containing fatigue cracks

Description: Report presenting cross-grain specimens made of 7075-T6 aluminum-alloy extrusion were subjected to repeated axial loads until fatigue cracks of various lengths were formed. The specimens were subjected to static tests to determine the residual static strength.
Date: April 1957
Creator: Illg, Walter & McEvily, Arthur J., Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Method of calculating core dimensions of crossflow heat exchanger with prescribed gas flows and inlet and exit states

Description: Report presenting a calculation procedure by which the dimensions of the core of a gas-to-gas crossflow heat exchanger with prescribed heat-transfer surface can be determined rapidly. The procedure is based on a number of charts that may be prepared for each surface with prescribed entrance conditions, pressure drops, and temperature changes.
Date: April 1956
Creator: Eckert, E. R. G. & Diaguila, Anthony J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A note on the effect of heat transfer on peak pressure rise associated with separation of turbulent boundary layer on a body of revolution (NACA RM-10) at a Mach number of 1.61

Description: Report presenting an investigation to determine the effect of heat transfer on the peak pressure rise associated with the separation of a turbulent boundary layer on a body of revolution at Mach number 1.61. The results indicated that little or no effect of heat transfer on the shock angles associated with separation on the peak pressure rise required to separate a turbulent boundary layer.
Date: April 1957
Creator: Czarnecki, K. R. & Sinclair, Archibald R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Ground Simulator Studies of the Effects of Valve Friction, Stick Friction, Flexibility, and Backlash on Power Control System Quality

Description: Note presenting tests on a power control system by means of a ground simulator to determine the effects of various combinations of valve friction and stick friction on the ability of the pilot to control the system. The results show that, when valve friction was present in a rigid system, the introduction of stick friction was beneficial in that it restored some of the quality lost because of the valve friction. Results regarding the rigid control system, flexible control system, and control sy… more
Date: April 1957
Creator: Brown, B. Porter
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Discharge coefficients for combustor-liner air-entry holes 1: Circular holes with parallel flow

Description: Report presenting an experimental investigation to determine the effects of various geometric and flow factors on the discharge coefficients for circular holes with flow parallel to the plane of the hole. The geometric and flow factors considered were hole diameter, wall thickness at the hole, parallel-flow duct height, boundary-layer thickness, parallel-flow velocity, static-pressure level, and pressure ratio across the test hole.
Date: April 1956
Creator: Dittrich, Ralph T. & Graves, Charles C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Measurements of the Nonlinear Variation With Temperature of Heat-Transfer Rate From Hot Wires in Transonic and Supersonic Flow

Description: Note presenting equilibrium temperatures and heat-transfer rates for 0.00015- and 0.00030-inch diameter tungsten wires normal to the flow throughout a range of Mach numbers and Reynolds numbers. For the range of variables, equilibrium temperature of the hot wire is characterized by constant recovery factor for subsonic Mach numbers but constant equilibrium to total temperature ratio for supersonic Mach numbers. Results regarding the equilibrium temperature tests and heat-transfer tests are prov… more
Date: April 1957
Creator: Winovich, Warren & Stine, Howard A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Rupture strength of several nickel-base alloys in sheet form

Description: The 100-hour rupture strengths of Inconel X, Inconel 700, Incoloy 901, Refractaloy 26, and R-235 at 1200 and 1350 F. in both the annealed and heat-treated conditions were determined. Inconel 700 had the highest rupture strength at both temperatures; Incoloy 901 was second strongest at 1200 F, and R-235 second strongest at 1350 F. With the exception of Incoloy 901, ductility was low. Photomicrographs show that fractures are through the grain boundaries. Results are compared with published data f… more
Date: April 1957
Creator: Dance, James H. & Clauss, Francis J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Further Experiments on the Stability of Laminar and Turbulent Hydrogen-Air Flames at Reduced Pressures

Description: "Stability limits for laminar and turbulent hydrogen-air burner flames were measured as a function of pressure, burner diameter, and composition. On the basis of a simple flame model, turbulent flashback involved a smaller effective penetration distance than laminar flashback. No current theoretical treatment predicts the observed pressure and diameter dependence of laminar and turbulent blowoff" (p. 1).
Date: April 1957
Creator: Fine, Burton
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Investigation of a full-scale, cascade-type thrust reverser

Description: A double set of turning vanes was carried inside the jet tailpipe. To produce reverse thrust, the tailpipe opens into two side sections and the turning vanes move outward to form a V-shaped cascade, which deflects the exhaust-gas flow. Forward and reverse net thrust were measured over a range of engine speeds with the airplane stationary. Taxi tests were made to determine the comparative stopping distances using wheel braking and reverse thrust separately, and a combination of both. The effect … more
Date: April 1957
Creator: Kohl, Robert C. & Algranti, Joseph S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The linearized subsonic flow about symmetrical nonlifting wing-body combinations

Description: Report presenting methods for determining the linearized subsonic flow about symmetrical, nonlifting wing-body combinations. A comparison of theory and experiment is made for two 45 degree sweptback wings in combination with basic Sears-Haack bodies of revolution and in combination with basic bodies indented according to the transonic area rule.
Date: April 1957
Creator: McDevitt, John B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Survey of the acoustic near field of three nozzles at a pressure ratio of 30

Description: The sound pressures radiating from the exhaust streams of two convergent-divergent and one convergent nozzle were measured. Exit diameters were 1.206 in. for the expanded nozzle and 0.625 in. for the convergent nozzle. The results are presented in a series of contour maps of overall and fine 1/3-octave-band sound pressures. The location of the source of the noise in each 1/3-octave band in the frequency range of 30 to 16,000 cps and the total power radiated were determined and compared with tho… more
Date: April 1957
Creator: Mull, Harold R. & Erickson, John C., Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Investigation of semivaneless turbine stator designed to produce axially symmetrical free-vortex flow

Description: From Summary: "A semivaneless turbine stator designed to eliminate blade wakes and secondary-flow accumulations of boundary-layer air was built and tested. Performance of this stator was evaluated with static pressures measured in the vaneless section and surveys of total pressure and flow angle made at the stator exit. Results are presented in terms of theoretical and experimental velocities and flow angles, boundary-layer parameters, and contours of total-pressure loss across the stator."
Date: April 1957
Creator: Rohlik, Harold E. & Wintucky, William T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Analysis of harmonic forces produced at hub by imbalances in helicopter rotor blades

Description: From Introduction: "First, an analysis of loads transmitted to the hub by balanced blades will be given. In the second section, the additional loads transmitted to the hub in a direction normal to the plane of rotation of the blades by imbalances in a rotor are derived. In the entire analysis, the results are given in terms of the forces transmitted to the hub by a single rotating helicopter blade in flight, and these are regarded as known or given."
Date: April 1958
Creator: Morduchow, M. & Muzyka, A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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