UNT Libraries Government Documents Department - 66 Matching Results

Search Results

Aerodynamic characteristics of NACA RM-10 missile in 8- by 6-foot supersonic wind tunnel at Mach numbers from 1.49 to 1.98 1: presentation and analysis of pressure measurements (stabilizing fins removed)

Description: Experimental investigation of flow about a slender body of revolution (NACA RM-10 missile) aligned and inclined to a supersonic stream was conducted at Mach numbers from 1.49 to 1.98 at a Reynolds number of approximately 30,000,000. Boundary-layer measurements at zero angle of attack are correlated with subsonic formulations for predicting boundary-layer thickness and profile. Comparison of pressure coefficients predicted by theory with experimental values showed close agreement at zero angle of attack and angle of attack except over the aft leeward side of body. At angle of attack, pitot pressure measurements in plane of model base indicated a pair of symmetrically disposed vortices on leeward side of body.
Date: July 20, 1950
Creator: Luidens, Roger W. & Simon, Paul C.

Aerodynamic characteristics of NACA RM-10 missile in 8- by 6-foot supersonic wind tunnel at Mach numbers from 1.49 to 1.98 2: presentation and analysis of force measurements

Description: Experimental investigation of aerodynamic forces acting on body of revolution (NACA RM-10 missile) with and without stabilizing fins was conducted at Mach numbers from 1.49 to 1.98 at angles of attack from 0 to 9 degrees and at Reynolds number of approximately 30,000,000. Comparison of experimental lift, drag, and pitching-moment coefficients and center of pressure location for body alone is made with linearized potential theory and a semiempirical method. Results indicate that aerodynamic characteristics were predicted more accurately by semiempirical method than by potential theory. Breakdown of measured drag coefficients into components of friction, pressure, and base-pressure drag is presented for body alone at zero angle of attack.
Date: July 21, 1950
Creator: Esenwein, Fred T.; Obery, Leonard J. & Schueller, Carl F.

Altitude-Chamber Performance of British Roll-Royce Nene II Engine 4: Effect of Operational Variables on Temperature Distribution at Combustion-Chamber Outlets

Description: "Temperature surveys were made at the combustion-chamber outlets of a British Rolls-Royce Nene II engine. The highest mean nozzle-vane and mean gas temperatures were found to occur at a radius approximately 75% of the nozzle-vane length from the inner ring of the nozzle-vane assembly. Variations in engine speed, jet-nozzle area, simulated altitude, and simulated flight speed altered the temperature level but did not materially affect the pattern of radial temperature distribution" (p. 1).
Date: July 3, 1950
Creator: Huntley, Sidney C.

Altitude-Chamber Performance of British Rolls-Royce Nene II Engine 3 - 18.00-Inch-Diameter Jet Nozzle

Description: An altitude-chamber investigation of British Rolls-Royce Nene II turbojet engine was conducted over range of altitudes from sea level to 65,000 feet and ram pressure ratios from 1.10 to 3.50, using an 18.00-inch-diameter jet nozzle. The 18.00-inch-diameter jet nozzle gave slightly lower values of net-thrust specific fuel consumption than either the 18.41- or the standard 18.75-inch-diameter jet nozzles at high flight speeds. At low flight speeds, the 18.41-inch-diameter jet nozzle gave the lowest value of net-thrust specific fuel consumption.
Date: July 10, 1950
Creator: Grey, Ralph E.; Brightwell, Virginia L. & Barson, Zelmar

An analysis of base pressure at supersonic velocities and comparison with experiment

Description: From Introduction: "The primary purpose of the investigation described in the present report is to formulate a method which is of value for quantitative calculations of base pressure on airfoils and bodies without boat-tailing. Part I consists of a detailed study of the base pressure in two-dimensional and axially-symmetric inviscid flow. In part II a semi-empirical theory is formulated since the results of part I indicate that an inviscid-flow theory cannot possibly be satisfactory for quantitative calculations of a viscous flow."
Date: July 1950
Creator: Chapman, Dean R.

Analysis of Turbulent Free-Convection Boundary Layer on Flat Plate

Description: "With the use of Karman's integrated momentum equation for the boundary layer and data on the wall-shearing stress and heat transfer in forced-convection flow, a calculation was carried out for the flow and heat transfer in the turbulent free-convection boundary layer on a vertical flat plate. The calculation is for a fluid with a Prandtl number that is close to 1. A formula was derived for the heat-transfer coefficient that was in good agreement with experimental data in the range of Grashof numbers from 10sup10 to 10sup12" (p. 1).
Date: July 12, 1950
Creator: Eckert, E. R. G. & Jackson, Thomas W.

Analytical and Experimental Investigation of Adiabatic Turbulent Flow in Smooth Tubes

Description: Note presenting equations derived for the prediction of velocity distributions for fully developed adiabtic turbulent flow in smooth tubes; both the incompressible and compressible flow cases were treated. The analysis produced a single equation that represents flow in both the conventional buffer layer and the laminar layer. The results for fully developed flow were correlated by using conventional dimensionless velocity and distance parameters, and agreed closely with those of Nikuradse and other investigators.
Date: July 1950
Creator: Deissler, Robert G.

Analytical investigation of flow and heat transfer in coolant passages of free-convection liquid-cooled turbines

Description: From Introduction: "An analytical investigation of the problems arising in connection with this cooling method was conducted at the NACA Lewis laboratory and is presented herein. This analysis investigates: (1) the smallest diameter hole that can be made without endangering the circulation of the liquid, and (2) methods of improving the circulation in a small-diameter hole."
Date: July 18, 1950
Creator: Eckert, E. R. G. & Jackson, Thomas W.

Analytical Investigation of Turbines With Adjustable Stator Blades and Effect of These Turbines on Jet-Engine Performance

Description: From Introduction: "A comparison is also made of the actual performance of two contemporary jet engines with estimated performance, assuming the engines were equipped with adjustable-angle stators and adjustable exhaust nozzles. Charts are presented that aid in estimating the performance of adjustable-stator turbines."
Date: July 17, 1950
Creator: Silvern, David H. & Slivka, William R.

Boundary-Layer Transition on a Cooled 20 Degree Cone at Mach Numbers of 1.5 and 2.0

Description: Note presenting an investigation of the laminar boundary layer on a cooled 20 degree cone at Mach numbers of 1.5 and 2.0 to determine the variation of the position of transition with surface temperature for both constant surface temperatures and surface temperatures that increased toward the rear of the cone. The increase in the extent of the laminar boundary layer for uniform surface temperatures was found to be directly proportional to the difference between the surface and recovery temperatures.
Date: July 1950
Creator: Scherrer, Richard

The calculation of downwash behind wings of arbitrary plan form at supersonic speeds

Description: Report presenting exact and approximate methods based on linearized supersonic flow theory for the calculation of the velocity potential and the downwash from thin wings of arbitrary plan form. The applicability of the method inherently depends on a knowledge of the load distribution over the plan form of the wing.
Date: July 1950
Creator: Martin, John C.

The calculation of modes and frequencies of a modified structure from those of the unmodified structure

Description: Report presenting a method that has been developed for the calculation of the natural coupled or uncoupled frequencies and modes of a structure with modifications directly from the known modes and frequencies of the unmodified structure. The method is advantageous when the modes and frequencies of the unmodified structure either are known or are required along with the modes and frequencies of the structure with various modifications.
Date: July 1950
Creator: Kruszewski, Edwin T. & Houbolt, John C.

Comparison of Model and Full-Scale Spin Test Results for 60 Airplane Designs

Description: Note presenting the results of spin-tunnel investigations compared with corresponding full-scale results for 60 different airplane designs. The purpose of the comparison was to determine the reliability of the model results in predicting full-scale spin and recovery characteristics. Results regarding the recovery characteristics, angle of attack, rate of rotation, altitude loss per revolution, angle of wing tilt, and emergency spin-recovery parachutes are provided.
Date: July 1950
Creator: Berman, Theodore

Comparison of outside-surface heat-transfer coefficients for cascades of turbine blades

Description: A comparison of available results from heat-transfer investigations on cascades of turbine blades is presented using the Nusselt equation. The conventional correlation procedure is modified by defining the Reynolds number by the average of the velocities and the pressures around the blades. The correlation of the results from impulse blades was improved by using the Reynolds number defined by the average velocity and pressure. The final comparison indicated that several variables, which possibly influence heat transfer, should be investigated.
Date: July 17, 1950
Creator: Hubbartt, James E.

Design and Applications of Hot-Wire Anemometers for Steady-State Measurements at Transonic and Supersonic Airspeeds

Description: Note presenting an investigation of the design requirements and heat-transfer characteristics of exposed-wire instruments to be used for steady-state measurements at transonic and supersonic speeds. Design criterions, construction details, and typical response behavior are presented.
Date: July 1950
Creator: Lowell, Herman H.

Development and Preliminary Investigation of a Method of Obtaining Hypersonic Aerodynamic Data by Firing Models Through Highly Cooled Gases

Description: Note presenting a method of investigating hypersonic aerodynamic phenomena by firing simple symmetrical models at high velocity through a very cold gas with a low sonic velocity. Schileren photographs and focused shadowgraphs were taken of cylindrical models with conical forebodies with apex angles of 30, 45, and 60 degrees.
Date: July 1950
Creator: Soule, Harold V. & Sabol, Alexander P.

Effect of Intense Sound Waves on a Stationary Gas Flame

Description: Intense sound waves with a resonant frequency of 5000 cycles per second were imposed on a stationary propane-air flame issuing from a nozzle. In addition to a slight increase of the flame velocity, a fundamental change both in the shape of the burning zone and in the flow pattern could be observed. An attempt is made to explain the origin of the variations in the flame configuration on the basis of transition at the nozzle from jet flow to potential flow.
Date: July 1950
Creator: Hahnemann, H. & Ehret, L.