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Average Outside-Surface Heat-Transfer Coefficients and Velocity Distributions for Heated and Cooled Impulse Turbine Blades in Static Cascades

Description: Heat-transfer investigation conducted on cooled as well heated impulse-type turbine blades in a static cascade to determine the effect of direction of heat flow on convective heat-transfer coefficients.
Date: March 9, 1951
Creator: Hubbartt, James E. & Schum, Eugene F.
Partner: UNT Libraries Government Documents Department

A Preliminary Investigation of Combustion With Rotating Flow in an Annular Combustion Chamber

Description: Memorandum presenting a preliminary investigation of flame-stability and flame-extinction characteristics of a propane-air mixture in an annular combustion chamber conducted with both straight and rotational flow. The rotating mixture burned at higher axial-inlet stream velocities and with more stable flames than could be obtained with straight-flow burning.
Date: September 18, 1951
Creator: Schwartz, Ira R.
Partner: UNT Libraries Government Documents Department

Fundamental Flame Velocities of Pure Hydrocarbons 3: Extension of Tube Method of High Flame Velocities - Acetylene-Air Mixtures

Description: Memorandum presenting an extension of the tube method of measuring flame velocities to fundamental flame velocities of 141 centimeters per second. The extension was accomplished by reducing the flame-tube diameter from 25 to 12.5 millimeters. Results regarding the gas flow and spatial flame velocity, flame surface area, and fundamental flame velocity are provided.
Date: December 3, 1951
Creator: Levine, Oscar & Gerstein, Melvin
Partner: UNT Libraries Government Documents Department

Preliminary Results of a Determination of Temperatures of Flames by Means of K-Band Microwave Attenuation

Description: "The temperature effects on the attenuation of K-band microwaves, at a frequency of 26,500 plus or minus 30 megacycles per second, through natural-gas and propane flames containing added alkali halide salts, were investigated over a temperature range from 1900 to 2500 K. The preliminary data of this investigation indicated that the attenuation varies appreciably with the sodium-line-reversal temperatures of the flames and is independent of the particular hydrocarbon fuels that were used for temperature sources and of the particular halide components of the compounds used in the concentrations employed to produce easily measurable attenuation. A reproducibility of plus or minus 25 K was obtainable" (p. 1).
Date: September 24, 1951
Creator: Rudlin, Leonard
Partner: UNT Libraries Government Documents Department

A Relation of Wind Shear and Insolation to the Turbulence Encountered by an Airplane in Clear-Air Flight at Low Altitudes

Description: Memorandum presenting the observed gust experience of an airplane and information on the associated meteorological conditions to obtain a simple empirical relation for estimating the intensity of turbulence in the earth's friction layer. The relation does not discriminate between differences in turbulence intensity resulting from variations of flight altitude or diurnal variations of turbulence.
Date: September 13, 1951
Creator: Thompson, James K.
Partner: UNT Libraries Government Documents Department

Experimental Investigation of Forced-Convection Heat-Transfer Characteristics of Lead-Bismuth Eutectic

Description: The forced-convection heat-transfer characteristics of lead-bismuth eutectic were experimentally investigated. Experimental values of Nusselt number for lead-bismuth fell considerably below predicted values. The addition of a wetting agent did not change the heat transfer characteristics.
Date: September 20, 1951
Creator: Lubarsky, Bernard
Partner: UNT Libraries Government Documents Department

Estimation of Neutron Energy for First Resonance From Absorption Cross Section for Thermal Neutrons

Description: Examination of published data for some 52 isotopes indicates that the neutron energy for which the first resonance occurs is related to the magnitude of the thermal absorption cross section. The empirical relation obtained is in qualitative agreement with the results of a simplified version of the resonance theory of the nucleus of Breit-Wigner.
Date: September 17, 1951
Creator: Bogart, Donald
Partner: UNT Libraries Government Documents Department

Cooperative Investigation of Relationship Between Static and Fatigue Properties of Heat-Resistant Alloys at Elevated Temperatures

Description: Memorandum presenting a study of the relationship between the static and dynamic properties of heat-resistant alloys at high temperatures. An auxiliary objective is to provide a better basis for evaluating the results from the various types of fatigue machines.
Date: March 7, 1951
Creator: NACA Subcommittee on Heat-Resisting Materials
Partner: UNT Libraries Government Documents Department

A Multiple-Range Self-Balancing Thermocouple Potentiometer

Description: "A multiple-range potentiometer circuit is described that provides automatic measurement of temperatures or temperature differences with any one of several thermocouple-material pairs. Techniques of automatic reference junction compensation, span adjustment, and zero suppression are described that permit rapid selection of range and wire material, without the necessity for restandardization, by setting of two external tap switches" (p. 1).
Date: November 5, 1951
Creator: Warshawsky, I. & Estrin, M.
Partner: UNT Libraries Government Documents Department

Summary of Results Obtained by Transonic-Bump Method on Effects of Plan Form and Thickness on Lift and Drag Characteristics of Wings at Transonic Speeds

Description: Memorandum presenting a summary of the effects of plan form and thickness on the lift and drag characteristics of wings at transonic speeds. The data was obtained during a transonic research program conducted in the high-speed 7- by 10-foot tunnel by the transonic-bump method. Results regarding lift, drag at zero lift, and drag due to lift are provided.
Date: November 30, 1951
Creator: Polhamus, Edward C.
Partner: UNT Libraries Government Documents Department

A Method for the Design of Sweptback Wings Warped to Produce Specified Flight Characteristics at Supersonic Speeds

Description: Memorandum presenting a method for designing a wing to be self-trimming at a given set of flight conditions. The spanwise distribution of load on the wing is made to be approximately elliptical, in an effort to maintain low wing drag. The procedure is illustrated using several examples.
Date: September 12, 1951
Creator: Tucker, Warren A.
Partner: UNT Libraries Government Documents Department

Flow Separation Ahead of a Blunt Axially Symmetric Body at Mach Numbers 1.76 to 2.10

Description: "The pressure distribution and drag were determined for a spherical-nosed axially symmetric body with thin projecting rods at Mach numbers of 1.76, 1.93, and 2.10. The upstream projection distance of the rods was varied over a wide range to study changes in the character of the flow separation and to determine the variation of drag and pressure distribution with tip projection. Drag coefficients between 0.18 and 0.30 were obtained for most tip projections at each Mach number" (p. 1).
Date: December 12, 1951
Creator: Moeckel, W. E.
Partner: UNT Libraries Government Documents Department

Preliminary Investigation of Use of Conical Flow Separation for Efficient Supersonic Diffusion

Description: Use of flow separation on a rod projecting upstream of a blunt body to decelerate the supersonic stream ahead of an annular nose inlet was investigated at Mach numbers of 1.76, 1.93, and 2.10. Maximum pressure recoveries were obtained with rod tip projections about 1.5 times the radius of the spherical nose and were higher than those obtained with single-shock solid cones. Subcritical operation was similar to that observed with solid-cone inlets, but the effect of angle of attack on maximum pressure recovery was more severe.
Date: December 17, 1951
Creator: Moeckel, W. E. & Evans, P. J., Jr.
Partner: UNT Libraries Government Documents Department

Effects of Reynolds Number on the Aerodynamic Characteristics of a Delta Wing at Mach Number of 2.41

Description: Memorandum presenting the results of an experimental investigation to determine the effects of Reynolds number on the flow characteristics over a delta wing at a Mach number 2.41. The wing streamwise airfoil sections are based on the NACA 00-thickness series with the maximum thickness varying from 4 percent at the root section to 6.24 percent at the 90-percent spanwise station. Results regarding force data and pressure-distribution data are provided.
Date: October 22, 1951
Creator: Hatch, John E., Jr. & Hargrave, L. Keith
Partner: UNT Libraries Government Documents Department

Correlation of Analog Solutions With Experimental Sea-Level Transient Data for Controlled Turbine-Propeller Engine, Including Analog Results at Altitudes

Description: Memorandum presenting a satisfactory correlation obtained between experimental sea-level transient data at constant flight speed and solutions from the analog representation. The representation is accomplished by transfer functions formed from a frequency-response analysis, which is then used to compute system response at altitude.
Date: August 24, 1951
Creator: Lazar, James & DeRocher, Wilfred L., Jr.
Partner: UNT Libraries Government Documents Department

System Analyses and Autopilot Design for Automatic Roll Stabilization of a Supersonic Pilotless Aircraft

Description: Memorandum presenting system analyses and autopilot design procedure for a supersonic pilotless aircraft with twin jet engines. The autopilots investigated were a gyro-actuated control, a gyro-actuated control with a rate-sensing device, and an electronic-hydraulic autopilot. Results regarding the airframe and gyro-actuated control system; airframe, gyro-actuated control, and rate servo; airframe and electronic-hydraulic autopilot; and contribution of method of analysis to system design are provided.
Date: July 11, 1951
Creator: Zarovsky, Jacob
Partner: UNT Libraries Government Documents Department

Forced-Convection Heat Transfer to Water at High Pressures and Temperatures in the Nonboiling Region

Description: "Forced-convection heat-transfer data have been obtained for water flowing in an electrically heated tube of circular cross section at water pressures of 200 and 2000 pounds per square inch, and temperatures in the nonboiling region, for water velocities ranging between 5 and 25 feet per second. The results indicate that conventional correlations can be used to predict heat-transfer coefficients for water at pressures up to 2000 pounds per square inch and temperatures in the nonboiling region" (p. 1).
Date: November 29, 1951
Creator: Kaufman, S. J. & Henderson, R. W.
Partner: UNT Libraries Government Documents Department

Effect of Surface Finish on Fatigue Properties at Elevated Temperatures 1: Low-Carbon N-155 With Grain Size of A.S.T.M. 1

Description: Effect of three surface finishes of roughness 4 to 5, 20 to 25, and 70 to 80 micro inches rms on fatigue properties were determined for low-carbon N-155 alloy of grain size A.S.T.M. 1 at temperatures of 80 , 1000, 1350, and 1500 F. The fatigue properties for the various finishes differed appreciably at room temperature; however, after short periods at 1000 F and for all periods investigated at temperatures above 1000 F, the specimen finishes had the same fatigue strength. It was concluded that the primary cause of the difference in room-temperature strength was due to compressive stresses set up in the surface and that at elevated temperatures these compressive stresses were relieved by annealing.
Date: June 26, 1951
Creator: Ferguson, Robert R.
Partner: UNT Libraries Government Documents Department

Preliminary Investigation of Helmholtz Resonators for Damping Pressure Fluctuations in 3.6-Inch Ram Jet at Mach Number 1.90

Description: Memorandum presenting an investigation conducted at Mach number 1.90 to determine if Helmholtz resonators can be used in a typical ramjet configuration to damp pressure pulsations associated with shock oscillations. Only one of the two resonators was found to effectively damp pressure pulsations that occurred when the ram jet was operating in the vicinity of its peak pressure recovery. Neither was found to effectively damp pressure pulsations over the entire range of ramjet operating conditions.
Date: May 22, 1951
Creator: Fox, Jerome L.
Partner: UNT Libraries Government Documents Department

Thermal Conductivity of 14 Metals and Alloys Up to 1100 Degrees Fahrenheit

Description: Memorandum presenting a determination of the thermal conductivity of 14 metals and alloys in temperatures ranges with a maximum of 1100 degrees Fahrenheit. Some of the metals included steels, high-temperature alloys, molybdenum disilicide, aluminum alloys, brass, and silver. A comparison method was used to obtain the results in which the thermal conductivity of the test sample was compared with the conductivity of high-purity lead.
Date: March 2, 1951
Creator: Evans, Jerry E., Jr.
Partner: UNT Libraries Government Documents Department

A wind-tunnel investigation of the aerodynamic characteristics of a full-scale sweptback propeller and two related straight propellers

Description: Report presenting an investigation of an NACA 10-(1.7)(062)-057-27 two-blade swept propeller was conducted int he 16-foot high-speed tunnel over a range of blade-angle settings. Two related straight propellers were also tested over the same operating range as the swept propeller. Results regarding envelope efficiency, effect of compressibility on maximum efficiency, effect of sweep on power coefficient, constant-power propeller operation, and effect of sweep on propeller-blade loading are provided.
Date: January 4, 1951
Creator: Evans, Albert J. & Liner, George
Partner: UNT Libraries Government Documents Department

Preliminary evaluation of the air and fuel specific-impulse characteristics of several potential ram-jet fuels 4: hydrogen, a-methylnaphthalene, and carbon

Description: A preliminary analytical evaluation of the air and fuel specific-impulse characteristics of hydrogen, a-methylnapthalene, and graphite carbon has been made. Adiabatic constant-pressure combustion flame temperatures for each fuel at several equivalence ratios were calculated for an initial air temperature of 560 degrees R and a pressure of 2 atmospheres.
Date: August 31, 1951
Creator: Gammon, Benson E.
Partner: UNT Libraries Government Documents Department

Data presentation of force characteristics of several engine-strut-body configurations at Mach numbers of 1.8 and 2.0

Description: Investigation to determine lift, drag, and pitching-moment characteristics of several engine-strut-body combinations was conducted over range of angles of attack from 0 degrees to 10 degrees at Mach numbers of 1.8 and 2.0. The average Reynolds number based on body length was 28x106. Data are presented without analysis and indicate decreases in minimum drag and lift curve slope with decreasing in minimum drag and lift curve slope with decreasing strut length. Decreases in minimum drag also noted with rear-ward movement of engines.
Date: August 14, 1951
Creator: Madden, Robert T. & Kremzier, Emil J.
Partner: UNT Libraries Government Documents Department

Investigation of altitude ignition, acceleration and steady-state operation with single combustor of J47 turbojet engine

Description: Report describing an investigation conducted with a single combustor from a J47 turbojet engine using weathered aviation gasoline and several spark-plug modifications to determine altitude ignition, acceleration, and steady-state operating characteristics. Results regarding ignition, acceleration, altitude operational limits, combustion efficiency, and pressure loss are provided.
Date: March 5, 1951
Creator: Cook, William P. & Butze, Helmut F.
Partner: UNT Libraries Government Documents Department