Combustion efficiencies in hydrocarbon-air systems at reduced pressures (open access)

Combustion efficiencies in hydrocarbon-air systems at reduced pressures

Report presenting results obtained with quiescent fuel-air mixtures and with small diffusion flames, which indicate that combustion efficiencies close to 100 percent were obtained at pressure much lower than those found in turbojet combustors at altitudes of 60,000 feet.
Date: September 13, 1950
Creator: Hibbard, Robert R.; Drell, Isadore L.; Metzler, Allen J. & Spakowski, Adolph E.
System: The UNT Digital Library
Gust-Tunnel Investigation of the Effect of Leading Edge Separation on the Normal Accelerations Experienced by a 45 Degree Sweptback-Wing Model in Gusts (open access)

Gust-Tunnel Investigation of the Effect of Leading Edge Separation on the Normal Accelerations Experienced by a 45 Degree Sweptback-Wing Model in Gusts

Report presenting an investigation of a 45 degree sweptback-wing model with interchangeable round and sharp leading edges to determine the effect of leading-edge separation on the loads experienced by the models in gusts. Leading-edge separation was found to increase the gust load, which appeared to vary based on the gust-gradient distance and velocity.
Date: November 24, 1953
Creator: Cahen, George L.
System: The UNT Digital Library
Correlation of laboratory smoke test with carbon deposition in turbojet combustors (open access)

Correlation of laboratory smoke test with carbon deposition in turbojet combustors

Report presenting a correlation of carbon deposition of 19 fuels in a turbojet combustor as a function of the boiling point and of the flame height at the sooting point of the fuels in a simple wick lamp for a particular combustor operating at a single set of conditions. Two similar investigations with different combustors, operating conditions, and nine different fuels yielded similar correlations on the same graph.
Date: February 3, 1950
Creator: Busch, Arthur M.
System: The UNT Digital Library
Performance of an All-Internal Conical Compression Inlet with Annular Throat Bleed at Mach Number 5.0 (open access)

Performance of an All-Internal Conical Compression Inlet with Annular Throat Bleed at Mach Number 5.0

From Summary: "An all-internal conical compression inlet with annular bleed at the throat was investigated at Mach 5.0 and zero angle of attack. The minimum contraction ratio of the supersonic diffuser, coincident with a mass-flow ratio of 1.0, was determined to be 0.084 as compared with the isentropic contraction ratio of 0.04 at Mach 5.0. The over-all inlet performance was very sensitive to the amount of annular bleed at the throat because of the extensive boundary layer."
Date: August 6, 1958
Creator: Stitt, Leonard E. & Obery, Leonard J.
System: The UNT Digital Library
Arrangement of Bodies of Revolution in Supersonic Flow to Reduce Wave Drag (open access)

Arrangement of Bodies of Revolution in Supersonic Flow to Reduce Wave Drag

"The wave drag of a combination of slender bodies of revolution at zero angle of attack is studied with a view to determining the arrangements for which the total drag is a minimum. Linearized theory is used to calculate the pressure distribution in the field surrounding the bodies. The interference drag coefficient is computed for different arrangements" (p. 1).
Date: December 17, 1951
Creator: Friedman, Morris D.
System: The UNT Digital Library
The Effects of Increasing the Leading-Edge Radius and Adding Forward Camber on the Aerodynamic Characteristics of a Wing With 35 Degrees of Sweepback (open access)

The Effects of Increasing the Leading-Edge Radius and Adding Forward Camber on the Aerodynamic Characteristics of a Wing With 35 Degrees of Sweepback

Report presenting a wind-tunnel investigation to determine the effects of a section modification on the aerodynamic characteristics of a wing with 35 degrees of sweepback. The wing was modified by increasing the leading-edge radius of the NACA 64A010 section and adding a small amount of camber to the forward portion of the chord. Lift, drag, pitching-moment, and trailing-edge-flap hinge-moment characteristics of the modified wing are compared with results from the original wing.
Date: February 9, 1951
Creator: Demele, Fred A. & Sutton, Fred B.
System: The UNT Digital Library
Experimental investigation of the drag of 30 degree, 60 degree, and 90 degree cone cylinders at Mach numbers between 1.5 and 8.2 (open access)

Experimental investigation of the drag of 30 degree, 60 degree, and 90 degree cone cylinders at Mach numbers between 1.5 and 8.2

Report presenting the total drag coefficients of 60 degree cone cylinders of fineness ratio 2.07 measured in free flight from Mach numbers of 1.5 to 8.2. Results regarding the smooth 60 degree cone cylinder, rifled models, and discontinuity lines in the shadowgraph pictures are provided.
Date: April 25, 1952
Creator: Seiff, Alvin & Sommer, Simon C.
System: The UNT Digital Library
A Preliminary Investigation of High-Speed Impact the Penetration of Small Spheres Into Thick Copper Targets (open access)

A Preliminary Investigation of High-Speed Impact the Penetration of Small Spheres Into Thick Copper Targets

Small metal spheres of various densities were fired at high speed into thick targets of copper and lead. In general, it was found that all of the penetrations could be correlated quite well for engineering purposes by a function relating the depth of penetration to the impact momentum per unit volume.
Date: May 28, 1958
Creator: Charters, A. C. & Locke, G. S., Jr.
System: The UNT Digital Library
Effects of leading-edge radius and maximum thickness-chord ratio on the variation with Mach number of the aerodynamic characteristics of several thin NACA airfoil sections (open access)

Effects of leading-edge radius and maximum thickness-chord ratio on the variation with Mach number of the aerodynamic characteristics of several thin NACA airfoil sections

Report presenting a wind-tunnel investigation to determine the effects of leading-edge radius and maximum thickness-chord ratio on the variation with Mach number of the aerodynamic characteristics of several thin symmetrical NACA 4-digit-series airfoil sections. The variations with Mach number of the lift, drag, and pitching moment for a 4-percent-chord-thick airfoil section are not significantly affected by a change of leading-edge radius from 0.18 to 0.53 percent of the chord. Results regarding the leading-edge radius effects and maximum thickness-chord ratio are provided.
Date: July 3, 1950
Creator: Berggren, Robert E. & Graham, Donald J.
System: The UNT Digital Library
Experimental and theoretical study of the interference at low speed between slender bodies and triangular wings (open access)

Experimental and theoretical study of the interference at low speed between slender bodies and triangular wings

Report presenting the aerodynamic characteristics of several wing-fuselage combinations measured at a Mach number of 0.25. Each combination consisted of a triangular wing with an aspect ratio of 2.0 and body of revolution with a fineness ratio of 12.5. Results regarding wings in the presence of bodies, wing-body combinations, and dorsal fins are provided.
Date: May 6, 1953
Creator: Hopkins, Edward J. & Carel, Hubert C.
System: The UNT Digital Library
The Ames Supersonic Free-Flight Wind Tunnel (open access)

The Ames Supersonic Free-Flight Wind Tunnel

Memorandum presenting a description of the Ames supersonic free-flight wind tunnel, which is a new piece of equipment for aerodynamic research at high supersonic Mach numbers. It has a wide Mach number range extending from low supersonic speeds to Mach numbers in excess of 10. The air stream in the tunnel is imperfect, mainly due to a symmetrical pair of oblique shock waves which reflect down the test section.
Date: April 25, 1952
Creator: Seiff, Alvin; James, Carlton S.; Canning, Thomas N. & Boissevain, Alfred G.
System: The UNT Digital Library
Investigation of altitude starting and acceleration characteristics of J47 turbojet engine (open access)

Investigation of altitude starting and acceleration characteristics of J47 turbojet engine

An investigation was conducted on an axial-flow-compressor type turbojet engine in the NACA Lewis altitude wind tunnel to determine the operational characteristics of several ignition systems, cross-fire tube configurations and fuel systems over a range of simulated flight conditions. The opposite-polarity-type spark plug provided the most satisfactory ignition. Increasing the cross-fire-tube diameter improved intercombustor flame propagation. At high windmilling speeds, accelerations to approximately 6200 rpm could be made at a preset constant throttle position. The use of a variable-area nozzle reduced acceleration time.
Date: January 10, 1951
Creator: Golladay, Richard L. & Bloomer, Harry E.
System: The UNT Digital Library
Low-Speed Characteristics of a 45 Degree Swept Wing with Leading-Edge Inlets (open access)

Low-Speed Characteristics of a 45 Degree Swept Wing with Leading-Edge Inlets

Memorandum presenting an investigation to determine the low-speed aerodynamic characteristics of a 45 degree swept wing with leading-edge inlets. The wing had a constant chord and completely spanned the wind tunnel. Results regarding surface-pressure characteristics, lift and pitching-moment characteristics, wake-drag characteristics, and internal-flow characteristics are provided.
Date: August 13, 1951
Creator: Dannenberg, Robert E.
System: The UNT Digital Library
Preliminary drag and heat-transfer data obtained from air-launched cone-cylinder test vehicle over Mach number range from 1.5 to 5.18 (open access)

Preliminary drag and heat-transfer data obtained from air-launched cone-cylinder test vehicle over Mach number range from 1.5 to 5.18

From Summary: "An air-launched cone-cylinder test vehicle designed to obtain data at Mach numbers above 4.0 was rocket boosted from a release Mach number of 5.18. The vehicle was launched at an altitude of 35,000 feet and reached peak velocity of 5150 feet per second at 28,500 feet. The total-drag coefficient (based on maximum cross-sectional area) decreased gradually from 0.31 at a Mach number of 1.75 to 0.145 at a Mach number of 5.18, while the Reynold's number (based on body length) increased from 31 x 10 to the 6th power to 107 x 10 to the 6th power."
Date: November 16, 1953
Creator: Messing, Wesley E.; Rabb, Leonard & Disher, John H.
System: The UNT Digital Library
Investigation at Low Speed of the Flow Field Behind the Lifting Surfaces of a Model Equipped With a 60 Degree Triangular Wing and a 60 Degree Triangular Canard Tail (open access)

Investigation at Low Speed of the Flow Field Behind the Lifting Surfaces of a Model Equipped With a 60 Degree Triangular Wing and a 60 Degree Triangular Canard Tail

Report presenting an investigation of the flow behind the lifting surfaces of a model equipped with a 60 degree triangular wing and a 60 degree triangular canard tail. Results regarding the force and moment data, air-stream surveys behind the wing, effective values of downwash and dynamic-pressure ratio, effect of tail height and length, a comparison with previous data, the effects of component area and ratio, and the effect of a canard tail are provided.
Date: June 29, 1953
Creator: Newman, Ernest E. & Cahill, Jones F.
System: The UNT Digital Library
Theoretical Investigation of an Automatic Control System With Primary Sensitivity to Normal Accelerations as Used to Control a Supersonic Canard Missile Configuration (open access)

Theoretical Investigation of an Automatic Control System With Primary Sensitivity to Normal Accelerations as Used to Control a Supersonic Canard Missile Configuration

Report presenting a theoretical investigation of an automatic control system with primary sensitivity to normal accelerations as used to control a specific supersonic canard missile. The control system is made up of an integrating servomotor that receives a signal from an accelerometer that is sensitive to normal accelerations of the airframe that it is controlling. The acceleration control system appears to work well for obtaining longitudinal control, but works best when combined with a homing seeker or guidance system for controlling directional space.
Date: July 10, 1951
Creator: Seaberg, Ernest C. & Smith, Earl F.
System: The UNT Digital Library
Effect of air distribution on radial temperature distribution in one-sixth sector of annular turbojet combustor (open access)

Effect of air distribution on radial temperature distribution in one-sixth sector of annular turbojet combustor

Report presenting an experimental investigation in a one-sixth sector of an annular turbojet combustor to determine a method of controlling radial exhaust-gas-temperature distribution in a gas-turbine combustion chamber. The adjustment in controlling air was made by ducting the dilution air into the combustion zone in a predetermined manner through hollow radial struts or by modifying the basket-wall open-hole area. Results regarding the temperature distribution, temperature-rise efficiency, total-pressure loss, and altitude operating limits are provided.
Date: April 5, 1950
Creator: Mark, Herman & Zettle, Eugene V.
System: The UNT Digital Library
Performance of a blunt-lip side inlet with ramp bleed, bypass, and a long constant-area duct ahead of the engine : Mach number 0.66 and 1.5 to 2.1 (open access)

Performance of a blunt-lip side inlet with ramp bleed, bypass, and a long constant-area duct ahead of the engine : Mach number 0.66 and 1.5 to 2.1

Unsteady shock-induced separation of the ramp boundary layer was reduced and stabilized more effectively by external perforations than by external or internal slots. At Mach 2.0 peak total-pressure recovery was increased from 0.802 to 0.89 and stable mass-flow range was increased 185 percent over that for the solid ramp. Peak pressure recovery occurred just before instability. The 7 and one-third-diameter duct ahead of the engine reduced large total-pressure distortions but was not as successful for small distortions as obtained with throat bleed. By removing boundary-layer air the bypass nearly recovered the total-pressure loss due to the long duct.
Date: December 28, 1956
Creator: Allen, John L.
System: The UNT Digital Library
Altitude-Wind-Tunnel Investigation of Combustion-Chamber Performance on J47 Turbojet Engine (open access)

Altitude-Wind-Tunnel Investigation of Combustion-Chamber Performance on J47 Turbojet Engine

From Introduction: "Results are presented to indicate the effect of altitude, flight Mach number, and exhaust-nozzle-outlet area on the combustion efficiency, the losses in total pressure occurring in the combustion chamber, and the fractional loss in engine cycle efficiency resulting from combustion-chamber pressure losses. The engine cycle efficiency is also presented.These results are shown graphically as a fraction of corrected engine speed and in tabular form."
Date: December 15, 1950
Creator: Campbell, Carl E.
System: The UNT Digital Library
Instrumentation of the Ames Supersonic Free-Flight Wind Tunnel (open access)

Instrumentation of the Ames Supersonic Free-Flight Wind Tunnel

Memorandum presenting a description of the equipment used in the Ames supersonic free-flight wind tunnel to obtain the data necessary to measure the aerodynamic characteristics of free-flying models. The model is fired from a gun into the supersonic air stream of a blowdown-type wind tunnel. The action resulting from aerodynamic forces is computed from a time-distance-attitude record of the model flight through the test section.
Date: April 24, 1952
Creator: Briggs, Robert O.; Kerwin, William J. & Schmidt, Stanley F.
System: The UNT Digital Library
Influence of airfoil trailing-edge angle and trailing-edge-thickness variation on the effectiveness of a plain flap at high subsonic Mach numbers (open access)

Influence of airfoil trailing-edge angle and trailing-edge-thickness variation on the effectiveness of a plain flap at high subsonic Mach numbers

Report presenting the effects of variation of trailing-edge angle and trailing-edge thickness on the lift characteristics of a 10-percent-chord thick symmetrical NACA airfoil section with a 25-percent-chord plain flap as determined from wind tunnel tests over a range of Mach numbers. Results regarding the section lift and pitching-moment characteristics, variation of lift coefficient with flap deflection, schileren photographs, and effect of angle of attack are provided.
Date: May 22, 1951
Creator: Hemenover, Albert D. & Graham, Donald J.
System: The UNT Digital Library
A theory for stability and buzz pulsation amplitude in ram jets and an experimental investigation including scale effects (open access)

A theory for stability and buzz pulsation amplitude in ram jets and an experimental investigation including scale effects

From Summary: "From a theory developed on a quasi-one-dimensional-flow basis, it was found that the stability of the ram jet is dependent upon the instantaneous values of mass flow and total pressure recovery of the supersonic diffuser and immediate neighboring subsonic diffuser. Conditions for stable and unstable flow were presented. The theory developed in the report was in agreement with the experimental data of the reports both of Sterbentz and Evvard and of Ferri and Nucci."
Date: October 15, 1953
Creator: Trimpi, Robert L.
System: The UNT Digital Library
Properties of Low-Carbon N-155 Alloy Bar Stock From 1200 to 1800 Degrees Fahrenheit (open access)

Properties of Low-Carbon N-155 Alloy Bar Stock From 1200 to 1800 Degrees Fahrenheit

Memorandum presenting the results of an investigation to establish rupture and total-deformation strengths at 1200 and 1800 degrees Fahrenheit for typical commercial treatments of low-carbon N-155 alloy. The results show that there were large differences in strength between the heats of bar stock at temperatures above 1200 degrees Fahrenheit except when a 2200 degree Fahrenheit solution treatment was used.
Date: May 3, 1951
Creator: Freeman, J. W. & White, A. E.
System: The UNT Digital Library