Analysis of parameters for thrust control of a turbojet engine equipped with air-inlet throttle and variable-area exhaust nozzle (open access)

Analysis of parameters for thrust control of a turbojet engine equipped with air-inlet throttle and variable-area exhaust nozzle

From Introduction: "In this report, altitude, airplane velocity, exhaust-nozzle area, and turbine-inlet temperature were chosen and corresponding engine speed, fuel flow, and throttle pressure ratio were found. A detailed discussion of the engine analysis and the calculations used are presented in Appendix A. The derivations of the principal equations used are presented in appendix B."
Date: August 10, 1948
Creator: Boksenbom, Aaron S. & Feder, Melvin S.
System: The UNT Digital Library
Investigation at supersonic speed (M = 1.53) of the pressure distribution over a 63 degrees swept airfoil of biconvex section at zero lift (open access)

Investigation at supersonic speed (M = 1.53) of the pressure distribution over a 63 degrees swept airfoil of biconvex section at zero lift

Report presenting an investigation of the distribution of pressure at zero lift over the surface of a swept airfoil of biconvex section. The measured pressures are compare with theoretical values calculated from thin-airfoil theory. Results regarding pressure distributions, drag, and boundary-layer studies are provided.
Date: June 10, 1948
Creator: Frick, Charles W. & Boyd, John W.
System: The UNT Digital Library
Wind-Tunnel Tests of a Swept-Blade Propeller and Related Straight Blades Having Thickness Ratios of 5 and 6 Percent (open access)

Wind-Tunnel Tests of a Swept-Blade Propeller and Related Straight Blades Having Thickness Ratios of 5 and 6 Percent

Report discussing the aerodynamic characteristics of three sets of blades over as wide a range of operating conditions as possible. One set of blades was conventional, one had blades that embodied sweep, and one was a nonswept set with thinner blade sections. The sweptback blades were found to be generally inferior to the straight blades, but the Mach numbers tested were not high enough to include speeds that might benefit from sweepback.
Date: November 10, 1948
Creator: Gray, W. H.
System: The UNT Digital Library
Aerodynamic Characteristics of Flying-Boat Hulls Having Length-Beam Ratios of 20 and 30 (open access)

Aerodynamic Characteristics of Flying-Boat Hulls Having Length-Beam Ratios of 20 and 30

Report discussing the aerodynamic effects of length-beam ratios 20 and 30 as compared to length-beam ratios from 6 to 15. There was slightly more longitudinal stability and slightly less directional stability than in the lower ratios and not much change in the minimum drag coefficient.
Date: November 10, 1948
Creator: Riebe, John M.
System: The UNT Digital Library
Theoretical and Experimental Analysis of Low-Drag Supersonic Inlets Having a Circular Cross Section and a Central Body at Mach Numbers of 3.30, 2.75, and 2.45 (open access)

Theoretical and Experimental Analysis of Low-Drag Supersonic Inlets Having a Circular Cross Section and a Central Body at Mach Numbers of 3.30, 2.75, and 2.45

Memorandum presenting a discussion of inlets with a circular cross section and a central body designed for high Mach numbers. The optimum proportion between external and internal supersonic compression is discussed in relation to the external drag and the maximum pressure recovery. Results and analysis regarding the maximum pressure recovery as a function of the cowling position parameter, the effect of the cone angle parameter on the maximum pressure recovery obtained, the highest pressure recovery obtained as a function of the central-body-diameter parameter, the maximum pressure recovery as a function of Mach number, and optical observations of the flow phenomena about the inlets are provided.
Date: November 10, 1948
Creator: Ferri, Antonio & Nucci, Louis M.
System: The UNT Digital Library
Note on the Importance of Imperfect-Gas Effects and Variation of Heat Capacities on the Isentropic Flow of Gases (open access)

Note on the Importance of Imperfect-Gas Effects and Variation of Heat Capacities on the Isentropic Flow of Gases

"The errors involved in using the perfect-gas law pv = RT and the assumption of constant heat capacities are evaluated. The basic equations of gas flows taking into account these phenomena separately and at the same time are presented" (p. 1).
Date: December 10, 1948
Creator: Donaldson, Coleman duP.
System: The UNT Digital Library
Effect of leading-edge high-lift devices and split flaps on the maximum-lift and lateral characteristics of a rectangular wing of aspect ratio 3.4 with circular-arc airfoil sections at Reynolds numbers from 2.9 x 10(exp 6)  to 8.4 x 10(exp 6) (open access)

Effect of leading-edge high-lift devices and split flaps on the maximum-lift and lateral characteristics of a rectangular wing of aspect ratio 3.4 with circular-arc airfoil sections at Reynolds numbers from 2.9 x 10(exp 6) to 8.4 x 10(exp 6)

Report regarding the results of an investigation at high Reynolds numbers and low Mach numbers in the full-scale tunnel to determine the effect of leading-edge high-lift devices and split flaps on the maximum-lift and lateral characteristics of a rectangular wing of aspect ratio 3.4 with circular-arc airfoil section. Results regarding the maximum lift and stalling characteristics on the basic wing, effect of split-flap deflection, effect of leading-edge high-lift devices, and lateral characteristics with the flaps are provided.
Date: November 10, 1948
Creator: Lange, Roy H. & May, Ralph W., Jr.
System: The UNT Digital Library
A Simple Approximate Method for Obtaining Spanwise Lift Distributions Over Swept Wings (open access)

A Simple Approximate Method for Obtaining Spanwise Lift Distributions Over Swept Wings

"It is shown how Schrenk's empirical method of estimating the lift distribution over straight wings can be adapted to swept wings by replacing the elliptical distribution by a new "ideal" distribution which varies with sweep.The application of the method is discussed in detail and several comparisons are made to show the agreement of the proposed method with more rigorous ones. It is shown how first-order compressibility corrections applicable to subcritical speeds may be included in this method" (p. 1).
Date: May 10, 1948
Creator: Diederich, Franklin W.
System: The UNT Digital Library
Altitude-Wind-Tunnel Investigation of a 3000-Pound-Thrust Axial-Flow Turbojet Engine, 7, Pressure and Temperature Distributions (open access)

Altitude-Wind-Tunnel Investigation of a 3000-Pound-Thrust Axial-Flow Turbojet Engine, 7, Pressure and Temperature Distributions

Temperature and pressure distributions for an original and modified 3000 pound thrust axial flow turbojet engine were investigated. Data are included for a range of simulated altitudes from 5000 to 45000 feet, Mach numbers from 0.24 to 1.08, and corrected engine speeds from 10,550 to 13,359 rpm.
Date: December 10, 1948
Creator: Saari, Martin J. & Prince, William R.
System: The UNT Digital Library
Preliminary Results of an Altitude-Wind-Tunnel Investigation of an Axial-Flow Gas Turbine-Propeller Engine 4 - Compressor and Turbine Performance Characteristics (open access)

Preliminary Results of an Altitude-Wind-Tunnel Investigation of an Axial-Flow Gas Turbine-Propeller Engine 4 - Compressor and Turbine Performance Characteristics

"As part of an investigation of the performance and operational characteristics of the axial-flow gas turbine-propeller engine, conducted in the Cleveland altitude wind tunnel, the performance characteristics of the compressor and the turbine were obtained. The data presented were obtained at a compressor-inlet ram-pressure ratio of 1.00 for altitudes from 5000 to 35,000 feet, engine speeds from 8000 to 13,000 rpm, and turbine-inlet temperatures from 1400 to 2100 R. The highest compressor pressure ratio obtained was 6.15 at a corrected air flow of 23.7 pounds per second and a corrected turbine-inlet temperature of 2475 degrees R" (p. 1).
Date: August 10, 1948
Creator: Wallner, Lewis E. & Saari, Martin J.
System: The UNT Digital Library
Determination of average heat-transfer coefficients for a cascade of symmetrical impulse turbine blades 1: heat transfer from blades to cold air (open access)

Determination of average heat-transfer coefficients for a cascade of symmetrical impulse turbine blades 1: heat transfer from blades to cold air

Report presenting an investigation to determine average outside surface heat-transfer coefficients for a cascade of symmetrical impulse turbine blades. Results regarding recovery factor, heat-transfer coefficients, effective gas temperature, turbine cascades, cylinders and streamline bodies, and application to rim-cooling theory are provided.
Date: November 10, 1948
Creator: Meyer, Gene L.
System: The UNT Digital Library
An Investigation of the Wing and the Wing-Fuselage Combination of a Full-Scale Model of the Republic XP-91 Airplane in the Ames 40-by 80-Foot Wing Tunnel (open access)

An Investigation of the Wing and the Wing-Fuselage Combination of a Full-Scale Model of the Republic XP-91 Airplane in the Ames 40-by 80-Foot Wing Tunnel

"Wind-tunnel tests of a full-scale model of the Republic XP-91 airplane were conducted to determine the longitudinal and lateral characteristics of the wing alone and the wing-fuselage combination, the characteristics of the aileron, and the damping in roll of the wing alone. Various high-lift devices were investigated including trailing-edge split flaps and partial- and full-span leading-edge slats and Krueger-type nose flaps. Results of this investigation showed that a very significant gain in maximum lift could be achieved through use of the proper leading-edge device" (p. 1).
Date: June 10, 1948
Creator: Hunton, Lynn W. & Dew, Joseph K.
System: The UNT Digital Library