UNT Libraries Government Documents Department - 68 Matching Results

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Analysis and modification of theory for impact of seaplanes on water

Description: From Summary: "An analysis of available theory on seaplane impact and a proposed modification thereto are presented. In previous methods the overall momentum of the float and virtual mass has been assumed to remain constant during the impact but the present analysis shows that this assumption is rigorously correct only when the resultant velocity of the float is normal to the keel."
Date: August 20, 1945
Creator: Mayo, Wilbur L.

Attainment of a Straight-Line Trajectory for a Preset Guided Missile With Special Reference to Effect of Wind or Target Motion

Description: Report discusses the results of a study "of the requirements for the attainment of a straight-line trajectory for a preset guided missile in the presence of wind or target motion" (from Summary). Information about the straight-line trajectory, position of the launching airplane, straight-line collision course, and arrangement of the autopilot in the missile is provided. Recommendations are also made about the creation of a bombsight mounting for the pilot of the launching airplane in order to attain the desired straight-line collision course.
Date: August 1945
Creator: Ribner, Herbert S.

Charts for Helicopter-Performance Estimation

Description: Report presenting charts relating helicopter aerodynamic design variables to performance in steady powered flight. The flight conditions covered are hovering, climb, and horizontal flight. The use of the charts is illustrated by numerical examples in order that computations can be made for particular problems.
Date: August 1945
Creator: Talkin, Herbert W.

Comparative drag measurements at transonic speeds of rectangular sweptback NACA 65-009 airfoils mounted on a freely falling body

Description: From Summary: "Directly comparable drag measurements have been made of an airfoil with a conventional rectangular plan form and an airfoil with a sweptback plan form mounted on freely falling bodies. Both airfoils had NACA 65-009 sections and were identical in span, frontal area, and chord perpendicular to the leading edge. The sweptback plan form incorporated a sweepback angle of 45 degrees. The data obtained have been used to establish the relation between the airfoil drag coefficients and the free-stream Mach number over a range of Mach numbers from 0.90 to 1.27. The results of the measurements indicate that the drag of the sweptback plan form is less than 0.3 that of the rectangular plan form at a Mach number of 1.00 and is less than 0.4 that at a Mach number of 1.20."
Date: August 9, 1945
Creator: Mathews, Charles W. & Thompson, Jim Rogers

Comparative Fatigue Tests of Riveted Joints of Alclad 24S-T, Alclad 24S-T81, Alclad 24S-RT, Alclad 24S-T86 and Alclad 75S-T Sheet

Description: Report discusses testing performed to determine the fatigue strength of various types of riveted and spot-welded joints in the following aluminum alloys: Alclad 24S-T, 24S-RT, 758-T, 24S-T81, and 24S-T86. Details of the experiment, tensile properties, and information about failure are provided.
Date: August 1945
Creator: Moore, R. L. & Hill, H. N.

Comparison of wind-tunnel and flight measurements of stability and control characteristics of a Douglas A-26 airplane

Description: From Summary: "Stability and control characteristics determined from tests in the Langley 19-foot pressure tunnel of a 0.2375-scale model of the Douglas XA-26 airplane are compared with those measured in flight tests of a Douglas A-26 airplane. Agreement regarding static longitudinal stability as indicated by the elevator-fixed neutral points and by the variation of elevator deflection in both straight and turning flight was found to be good except at speeds approaching the stall. At these low speeds the airplane possessed noticeably improved stability, which was attributed to pronounced stalling at the root of the production wing."
Date: August 11, 1945
Creator: Kayten, Gerald G. & Koven, William

Comparisons of Methods of Computing Bending Moments in Helicopter Rotor Blades in the Plane of Flapping

Description: Report presenting several methods of computing bending moments in helicopter rotor blades in the plane of flapping, and the results of a numerical example analyzed by four different methods are compared. The effect of computed bending moments of the tip-loss correction introduced by Wheatley is also considered.
Date: August 1945
Creator: Duberg, John E. & Luecker, Arthur R.

Computation of the Mean Tangential Velocity of the Air Leaving the Blade Tips of a Centrifugal Supercharger

Description: Report discusses the differences between the mean tangential velocity of the air leaving the blade tips of a centrifugal supercharger calculated by the conventional turbine equation and by an equation that uses the isentropic increase in total enthalpy. The velocities are compared to experimental values observed with three diffusers.
Date: August 1945
Creator: Brown, W. Byron

Correlation of Wind-Tunnel Predictions With Flight Tests of a Twin-Engine Patrol Airplane 2: Lateral- and Directional-Stability and Control Characteristics

Description: "The lateral- and directional-stability and -control characteristics of a twin-engine patrol airplane as predicted from the results of wind-tunnel tests of a powered model and as measured in flight are compared in this report. The predictions from wind-tunnel-test data were in good agreement with the flight-test results. The results show that such predicted flying-qualities characteristics are sufficiently accurate to indicate the unsatisfactory lateral- and directional-stability and -control characteristics of airplanes in the preliminary design stage" (p. 1).
Date: August 30, 1945
Creator: Delany, Noel K. & Kauffman, William M.

Determination of Air-Consumption Parameters for Two Radial Aircraft Engines

Description: "Air-consumption data from calibrations of two radial aircraft engines were analyzed to show the relation of engine air consumption to its primary influencing factors: intake-manifold pressure, exhaust back pressure, intake-manifold temperature, and engine speed. The analysis of the test data from these two engines led to the establishment of a relation of variables upon which the design of automatic metering controls can be based. The data obtained from one engine indicate that the air-consumption correlation obtained for this engine is accurate within 2 percent except under certain conditions that are well outside current engine-operation limits" (p. 1).
Date: August 1945
Creator: Shames, Sidney J. & Howes, William

The Effect of Geometry and Voltage Variations on the Operations of the Phillips Ion Gage

Description: Abstract: "The study of ten P.I.G. geometries with copper electrodes and d.c. voltage indicates that from a pressure of 0.1 to about 3.0 microns, depending upon the gage, there is a consistent change in the air pressure-current characteristics of a P.I.G. as the geometry and voltage are changed. At higher pressures discontinuities appear in the gage current and prohibit its use as a pressure gage. In all useful geometries, the greater the applied voltage above 1000 volts, the shorter the useful portion of the pressure-current curve became. Below 1000 volts the curve tended to be unstable. With other conditions constant, the pressure limit increased as the cathode separation decreased and as the anode diameter increased. The empirical equation for the current in certain Philips Ion Gages at certain pressures and voltages is I = a'Pe-p/b where I is the current, P the pressure, e the Naperian base and a' and b constants and dependent upon geometry and voltage."
Date: August 22, 1945
Creator: McKinney, C. R.; Eggen, Donald T.; Bishop, A.; Arnold, W. A. & Starr, C.

Effect of the Performance of a Turbosupercharged Engine of an Exhaust-Gas-to-Air Heat Exchanger for Thermal Ice Prevention

Description: This report presents the results of a flight investigation to determine the effect on the performance of a turbosupercharged engine of an exhaust-gas-to-air heat exchanger installed between the engine-exhaust collector ring and the turbosupercharger. The background, results, and discussion of the investigation are described.
Date: August 23, 1945
Creator: Look, Bonne C.

Effect of Variation in Diameter and Pitch of Rivets on Compressive Strength of Panels With Z-Section Stiffeners 1 - Panels With Close Stiffener Spacing That Fail by Local Buckling

Description: An experimental investigation is being conducted to determine the effect of varying the rivet diameter and pitch on the compressive strength of 24S-T aluminum-alloy panels with longitudinal Z-section stiffeners. The average stress at failing load for each rivet diameter, depth of countersink, and pitch of rivet is provided
Date: August 1945
Creator: Dow, Norris F. & Hickman, William A.

Effect of Water-Alcohol Injection and Maximum Economy Spark Advance on Knock-Limited Performance and Fuel Economy of a Large Air-Cooled Cylinder

Description: An investigation was conducted to determine the effect of a coolant solution of 25 percent ethyl alcohol, 25 percent methyl alcohol, and 50 percent water by volume and maximum-economy spark advance on knock-limited performance and fuel economy of a large air-cooled cylinder. The knock-limited performance of the cylinder at engine speeds of 2100 and 2500 rpm was determined for coolant-fuel ratios of 0.0, 0.2, and 0.4. The effect of water-alcohol injection on fuel economy was determined in constant charge-air flow tests. The tests were conducted at a spark advance of 20 deg B.T.C. and maximum-economy spark advance.
Date: August 12, 1945
Creator: Heinicke, Orville H. & Vandeman, Jack E.

Elimination of Galling of Pendulum-Vibration Dampers Used in Aircraft Engines

Description: Report presenting an analysis of the contact stresses in a damper installation of an aircraft engine that indicated that galling could be eliminated by increasing the diameters of damper pins and holes. Torsional-vibration pendulum dampers have been successful in minimizing vibrations at critical speeds in aircraft engines, but serious wearing problems are often encountered when using them. The damper used in this experiment did not suffer any type of damage after many hours of use.
Date: August 1945
Creator: Meyer, André J., Jr.

The evolution of iodine during metal dissolution

Description: During the dissolution in nitric acid of uranium metal which has been irradiated in a pile, radio-iodine (8.0 day) and radio-xenon (5.3 day) are liberated along with the oxides of nitrogen. Since in the plant these gases are discharged into the atmosphere, the presence of the activities (particularly radio-iodine because of its greater chemical reactivity) presents a physiological hazard. As a consequence, the cooling period (that is, the time between the discharge of the metal from the pile and the dissolution of the metal in nitric acid for the extraction of the product) should be sufficiently long so that the activities will have decreased through decay to the point where their concentrations in the atmosphere will not exceed 2.5 {times} 10{sup {minus}13} curies/cc* and 5 {times} 10{sup {minus}11} curies/cc* for radio-iodine and radio-xenon, respectively. A study was made of the existing information concerning the liberation of iodine and xenon during the dissolution of the metal and the information was summarized in a memorandum. At that time it was apparent that radio-iodine would present the greater hazard, and that very little was known about the factors governing the liberation of iodine during the metal dissolution. For this reason, an investigation of the factors involved in the liberation of iodine during metal dissolution was undertaken in the laboratory. This document describes the investigation and its results. 5 refs., 7 figs., 4 tabs.
Date: August 2, 1945

Flight and Test-Stand Investigation of High-Performance Fuels in Modified Double-Row Radial Air-Cooled Engines 2: Flight Knock Data and Comparison of Fuel Knock Limits With Engine Cooling Limits in Flight

Description: Report discussing tests on three fuels in a 14-cylinder double-row radial air-cooled engine at different engine speeds, blower ratios, and spark settings.
Date: August 4, 1945
Creator: White, H. Jack; Pragliola, Philip C. & Blackman, Calvin C.