National Advisory Committee for Aeronautics (NACA) - 735 Matching Results

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An analysis of the full-floating journal bearing

Description: Report discussing an analysis of the operating characteristics of a full-floating journal bearing, a bearing in which a floating sleeve is located between the journal and bearing surfaces, is presented together with charts from which the performance of such bearings may be predicted.
Date: January 1, 1947
Creator: Shaw, M C & Nussdorfer, T J , Jr
Partner: UNT Libraries Government Documents Department

Analysis, Verification, and Application of Equations and Procedures for Design of Exhaust-Pipe Shrouds

Description: Investigations were made to develop a simplified method for designing exhaust-pipe shrouds to provide desired or maximum cooling of exhaust installations. Analysis of heat exchange and pressure drop of an adequate exhaust-pipe shroud system requires equations for predicting design temperatures and pressure drop on cooling air side of system. Present experiments derive such equations for usual straight annular exhaust-pipe shroud systems for both parallel flow and counter flow. Equations and methods presented are believed to be applicable under certain conditions to the design of shrouds for tail pipes of jet engines.
Date: December 1947
Creator: Ellerbrock, Herman H.; Wcislo, Chester R. & Dexter, Howard E.
Partner: UNT Libraries Government Documents Department

Analytical and experimental investigation of bolted joints

Description: From Introduction: "The present paper contains the development of a recurrence formula for the bolt loads for the simplified case of a symmetrical butt joint with bolts spaced evenly in line with the applied load. The method presented herein is based on the fundamental relationship which was developed in reference 1 between the loads on any two successive bolts. The present paper also gives the results of an experimental investigation conducted to substantiate further the adequacy of the elastic theory as well as to yield additional data on the critical bolt load and the behavior of long joints in the plastic range and at the ultimate load."
Date: October 1947
Creator: Rosenfeld, Samuel J
Partner: UNT Libraries Government Documents Department

Analytical comparison of a standard turbojet engine, a turbojet engine with a tail-pipe burner, and a ram-jet engine

Description: From Introduction: "Experimental investigations (reference 1) have shown that in some cases the thrust can be more than doubled by means of tail-pipe burning. A comparison is made of a standard turbojet engine, whose thrust is augmented by tail-pipe burning, and a ram-jet engine. The performance characteristics for the ram-jet engine were computed entirely from theoretical considerations and on the assumption that the burner-inlet velocity was constant."
Date: February 10, 1947
Creator: Krebs, Richard P & Palasics, John
Partner: UNT Libraries Government Documents Department

Analytical Treatment of Normal Condensation Shock

Description: The condensation of water vapor in an air consequences: acquisition of heat (liberated heat vaporization; loss of mass on the part of the flowing gas (water vapor is converted to liquid); change in the specific gas constants and of the ratio k of the specific heats (caused by change of gas composition). A discontinuous change of state is therefore connected with the condensation; schlieren photographs of supersonic flows in two-dimensional Laval nozzles show two intersecting oblique shock fronts that in the case of high humidities may merge near the point of intersection into one normal shock front.
Date: July 1, 1947
Creator: Heybey
Partner: UNT Libraries Government Documents Department

An Anaylsis of Control Requirements and Control Parameters for Direct-Coupled Turbojet Engines

Description: Requirements of an automatic engine control, as affected by engine characteristics, have been analyzed for a direct-coupled turbojet engine. Control parameters for various conditions of engine operation are discussed. A hypothetical engine control is presented to illustrate the use of these parameters. An adjustable speed governor was found to offer a desirable method of over-all engine control. The selection of a minimum value of fuel flow was found to offer a means of preventing unstable burner operation during steady-state operation. Until satisfactory high-temperature-measuring devices are developed, air-fuel ratio is considered to be a satisfactory acceleration-control parameter for the attainment of the maximum acceleration rates consistent with safe turbine temperatures. No danger of unstable burner operation exists during acceleration if a temperature-limiting acceleration control is assumed to be effective. Deceleration was found to be accompanied by the possibility of burner blow-out even if a minimum fuel-flow control that prevents burner blow-out during steady-state operation is assumed to be effective. Burner blow-out during deceleration may be eliminated by varying the value of minimum fuel flow as a function of compressor-discharge pressure, but in no case should the fuel flow be allowed to fall below the value required for steady-state burner operation.
Date: January 1, 1947
Creator: Novik, David & Otto, Edward W.
Partner: UNT Libraries Government Documents Department

The application of high-temperature strain gauges to the measurements of vibratory stresses in gas-turbine buckets

Description: The feasibility of measuring the vibration in the buckets of a gas turbine under service conditions of speed and temperature was determined by use of a high temperature wire strain gauge cemented to a modified supercharger turbine bucket. A high-temperature wire strain gauge and the auxiliary mechanical and electrical equipment developed for the investigation are described.
Date: April 1, 1947
Creator: Kemp, R H; Morgan, W C & Manson, S S
Partner: UNT Libraries Government Documents Department

Application of the analogy between water flow with a free surface and two-dimensional compressible gas flow

Description: The theory of the hydraulic analogy -- that is, the analogy between water flow with a free surface and two-dimensional compressible gas flow -- and the limitations and conditions of the analogy are discussed. A test was run using the hydraulic analogy as applied to the flow about circular cylinders of various diameters at subsonic velocities extending into the supercritical range. The apparatus and techniques used in this application are described and criticized. Reasonably satisfactory agreement of pressure distributions and flow fields existed between water and air flow about corresponding bodies. This agreement indicated the possibility of extending experimental compressibility research by new methods.
Date: January 1, 1947
Creator: Orlin, W James; Lindner, Norman J & Butterly, Jack G
Partner: UNT Libraries Government Documents Department

Application of the analogy between water flow with a free surface and two-dimensional compressible gas flow

Description: From Introduction: "The development of the measuring apparatus and techniques is presented herein. The application of the analogy to flows through nozzles and about circular cylinders at subsonic velocities extending into supercritical range is also presented."
Date: February 1947
Creator: Orlin, W James; Lindner, Norman J & Bitterly, Jack G
Partner: UNT Libraries Government Documents Department

Buffeting of External Fuel Tanks at High Speeds on a Gruman F7F-3 Airplane

Description: Attempts were made to alleviate the buffeting of external fuel tanks mounted under the wings of a twin-engine Navy fighter airplane. The Mach number at which buffeting began was increased from 0,529 to 0.640 by streamlining the sway braces and by increasing the lateral rigidity of the sway brace system. Further increase of the Mach number, at which buffeting began to 0.725, was obtained by moving the external fuel tank to a position under the fuselage.
Date: January 29, 1947
Creator: Turner, Howard L.
Partner: UNT Libraries Government Documents Department

Buffeting of External Fuel Tanks at High Speeds on a Grumman F7F-3 Airplane

Description: Attempts were made to alleviate the buffeting of external fuel tanks mounted under the wings of a twin-engine Navy fighter plane. The Mach number at which the buffeting began was increased from 0.529 to 0.640 by streamlining the sway braces and increasing the lateral rigidity of the sway brace system. Further increases of the Mach number, at which buffeting began to 0.725, was obtained by moving the external fuel tank to a position under the fuselage.
Date: January 30, 1947
Creator: Turner, Howard L.
Partner: UNT Libraries Government Documents Department

Calculation of compressible flows past aerodynamic shapes by use of the streamline curvature

Description: A simple approximate method is given for the calculation of isentropic irrotational flows past symmetrical airfoils, including mixed subsonic-supersonic flows. The method is based on the choice of suitable values for the streamline curvature in the flow field and the subsequent integration of the equations of motion. The method yields limiting solutions for potential flow. The effect of circulation is considered. A comparison of derived velocity distributions with existing results that are based on calculation to the third order in the thickness ratio indicated satisfactory agreement. The results are also presented in the form of a set of compressibility correction rules that lie between the Prandtl-Glauert rule and the von Karman-Tsien rule (approximately). The different rules correspond to different values of the local shape parameter square root sign YC sub a, in which Y is the ordinate and C sub a is the curvature at a point on an airfoil. Bodies of revolution, completely supersonic flows, and the significance of the limiting solutions for potential flow are also briefly discussed.
Date: June 1, 1947
Creator: Perl, W
Partner: UNT Libraries Government Documents Department