Boundary-Layer Transition at High Reynolds Numbers as Obtained in Flight of a 20 Degree Cone-Cylinder With Wall to Local Stream Temperature Ratios Near 1.0 (open access)

Boundary-Layer Transition at High Reynolds Numbers as Obtained in Flight of a 20 Degree Cone-Cylinder With Wall to Local Stream Temperature Ratios Near 1.0

Boundary-layer transition data at low ratios of wall to local stream temperature have been obtained during the free flight of a highly polished cone-cylinder to a maximum Mach number of 5.02 A maximum transition Reynolds number of 32 x 10(exp 6) occurred at a distance of 25.84 inches from the cone apex. The temperature ratio at transition for a local Mach number of 4.0 was approximately 1.30 as compared with theoretical infinite stability solutions of 1.47 and 1.65 by Dunn and Lin (three-dimensional) and Van Driest (two-dimensional), respectively.
Date: November 3, 1955
Creator: Rabb, Leonard & Disher, John H.
System: The UNT Digital Library
Effect of surface-active additives on physical properties of slurries of vapor-process magnesium (open access)

Effect of surface-active additives on physical properties of slurries of vapor-process magnesium

The presence of 3 to 5 percent surface-active additive gave the lowest Brookfield apparent viscosity, plastic viscosity, and yield value that were obtained for slurry fuels containing approximately 50 percent vapor-process magnesium in JP-1 fuel. The slurries settled little and were easily remixed. A polyoxyethylene dodecyl alcohol was the most effective of 13 additives tested in reducing the Brookfield apparent viscosity and the yield value of the slurry. The seven most effective additives all had a hydroxyl group plus an ester or polyoxethylene group in the molecule. The densities of some of the slurries were measured.
Date: November 3, 1955
Creator: Pinns, Murray L.
System: The UNT Digital Library
A Method for Determining the Composition of Methanol-Trimethyl Borate Mixtures (open access)

A Method for Determining the Composition of Methanol-Trimethyl Borate Mixtures

A study of mixtures of pure methanol and trimethyl borate showed that the composition can be accurately obtained by a simple density determination. The refractive-index determination gives the composition with much less accuracy. The potentiometric titration of boric acid is also discussed.
Date: November 3, 1955
Creator: Kaye, Samuel & Sordyl, Frank
System: The UNT Digital Library
Wind-Tunnel Measurements of the Dynamic Cross Derivative (Rolling Moment Due to Yawing Velocity and to Acceleration in Sideslip) of the Douglas D-558-II Airplane and Its Components at Supersonic Speeds Including Description of the Technique (open access)

Wind-Tunnel Measurements of the Dynamic Cross Derivative (Rolling Moment Due to Yawing Velocity and to Acceleration in Sideslip) of the Douglas D-558-II Airplane and Its Components at Supersonic Speeds Including Description of the Technique

Report presenting a technique and the results obtained of wind-tunnel forced-oscillation tests on a model of the Douglas D-558-II airplane which was instrumented to obtain the dynamic cross derivative and static derivative. Tests were conducted for a range of Mach numbers and angles of attack. Results regarding sample calculations of the period and damping of the full-scale airplane are provided despite not being conclusive due to the inadequate number of flight conditions investigated.
Date: November 3, 1955
Creator: Boatright, William B.
System: The UNT Digital Library
Analytical determination of effect of water injection on power output of turbine-propeller engine (open access)

Analytical determination of effect of water injection on power output of turbine-propeller engine

From Introduction: "Water injection at the compressor inlet has been successfully used to increase the thrust of turbojet engines. References 1 and 2 indicate that the sea-level static thrust of a centrifugal-flow-type turbojet engine may be increased about 25 percent by use of liquid injection. Reference 3 indicates that greater thrust augmentation is possible at a compressor pressure ratio of 11 than of 4."
Date: November 3, 1949
Creator: Ross, Albert O. & Huppert, Merle C.
System: The UNT Digital Library
Investigation of interaction effects arising from side-wall boundary layers in supersonic wind-tunnel tests of airfoils (open access)

Investigation of interaction effects arising from side-wall boundary layers in supersonic wind-tunnel tests of airfoils

Report presenting an investigation to determine the cause for a discrepancy between theoretical and experimental pressure distributions found during a two-dimensional investigation of flapped airfoils in a 2- by 8-inch supersonic tunnel. The results indicated that a tunnel-boundary-layer and model-flow interaction effect on the flow over models mounted directly from the walls in supersonic wind tunnels exists.
Date: November 3, 1948
Creator: Czarnecki, K. R. & Schueller, C. F.
System: The UNT Digital Library
Vibration of loosely mounted turbine blades during service operation of a turbojet engine with centrifugal compressor and straight-flow combustion chambers (open access)

Vibration of loosely mounted turbine blades during service operation of a turbojet engine with centrifugal compressor and straight-flow combustion chambers

Report presenting an experimental investigation to determine the vibration characteristics of loosely mounted turbine blades during service operation of a turbojet engine. High-temperature strain gages were used to measure turbine-blade vibrations. Results regarding oscillograph records, critical speeds and frequencies, vibratory-stress levels, and effect of tightening the blade mount are provided.
Date: November 3, 1949
Creator: Morgan, W. C.; Kemp, R. H. & Manson, S. S.
System: The UNT Digital Library
Pressure Distributions Over a Wing-Fuselage Model at Mach Numbers of 0.4 to 0.99 and at 1.2 (open access)

Pressure Distributions Over a Wing-Fuselage Model at Mach Numbers of 0.4 to 0.99 and at 1.2

Report presenting pressure distributions over a prolate spheroid of fineness ratio 6 and over a combination of this body with an NACA 65-010 wing section for a range of Mach numbers. Results regarding wall and sting interference, nature of flow over a model in the transonic region, development of supersonic flow from subsonic flow, and a comparison of experimental and theoretical flow at subsonic stream Mach numbers are provided.
Date: November 3, 1948
Creator: Matthews, Clarence W.
System: The UNT Digital Library
Preliminary Correlation of the Effect of Compressibility on the Location of the Section Aerodynamic Center at Subcritical Speeds (open access)

Preliminary Correlation of the Effect of Compressibility on the Location of the Section Aerodynamic Center at Subcritical Speeds

Memorandum presenting a correlation of available two-dimensional airfoil data to determine the effects of compressibility on the location of the section aerodynamic center at low lift coefficients. The results indicate that large forward or rearward movements of the aerodynamic center with Mach number are possible.
Date: November 3, 1948
Creator: Polhamus, Edward C.
System: The UNT Digital Library
Fundamental flame velocities of pure hydrocarbons 2: alkadienes (open access)

Fundamental flame velocities of pure hydrocarbons 2: alkadienes

Data are presented for the fundamental flame velocities of 10 pure alkadienes that have isolated, conjugated, or cumulative double-bond systems. On the basis of this limited amount of data and the flame velocities previously reported, it is concluded that unsaturation changes the flame velocity in the order alkanes ? alkenes ? alkadienes with isolated double bonds ?= alkadienes with conjugated double bonds ? alkadienes with cumulative double bonds ?= alkynes. There were no significant differences in the flame velocities of cis and trans 1,3-pentadiene. The alkadienes 1,2-pentadiene and 2,3-pentadiene, with different positions of the cumulative double bond in the straight chain, have similar flame velocities. Methyl substitution in a hydrocarbon reduces the flame velocity; the extent of the reduction increases with the degree of unsaturation of the hydrocarbon.
Date: November 3, 1950
Creator: Levine, Oscar; Wong, Edgar L. & Gerstein, Melvin
System: The UNT Digital Library
Low-speed static longitudinal and lateral stability characteristics of a model with leading-edge chord-extensions incorporated on a 40 degree sweptback circular-arc wing of aspect ratio 4 and taper ratio 0.50 (open access)

Low-speed static longitudinal and lateral stability characteristics of a model with leading-edge chord-extensions incorporated on a 40 degree sweptback circular-arc wing of aspect ratio 4 and taper ratio 0.50

Report presenting an investigation to determine the aerodynamic effects at low speed of several wing leading-edge chord-extensions incorporated on a complete model with a 40 degree sweptback circular-arc wing of aspect ratio 4 and taper ratio 0.50. Testing indicated that the effectiveness of the chord-extension in increasing the stability is mainly dependent on the spanwise inboard-end location of the device. Results regarding the static longitudinal characteristics and effect of chord-extension span and overhang on the lateral-stability parameters are provided.
Date: November 3, 1952
Creator: Goodson, Kenneth W. & Few, Albert G., Jr.
System: The UNT Digital Library
Performance of four experimental high btu-per-gallon fuels in a single turbojet combustor (open access)

Performance of four experimental high btu-per-gallon fuels in a single turbojet combustor

Performance characteristics of four hydrocarbon fuels having high Btu per gallon were determined in a single turbojet combustor. At simulated low-altitude operating conditions, the fuels with high Btu per gallon generally produced more carbon than did JP-4 and JP-5 fuels. The deposits were reduced appreciably with a fuel-oil additive. At high-altitude conditions, the high Btu-per-gallon fuels gave lower efficiencies than did JP-4 or JP-5 fuels. No attempts were made to improve performance by combustor design modification.
Date: November 3, 1955
Creator: Jonash, Edmund R.; Metzler, Allen J. & Butze, Helmut F.
System: The UNT Digital Library
General Characteristics of a Airspeed System using Fuselage Static Vents on a Swept-Wing Airplane (open access)

General Characteristics of a Airspeed System using Fuselage Static Vents on a Swept-Wing Airplane

"Studies have been made by the NACA wing-flow method of the use of fuselage static orifices between the wing and tail of a swept-wing airplane for possible application to service airspeed installations. The tests were made at zero angle of attack. The results indicate that, although the maximum errors are large, these locations are usable from the consideration that the local Mach numbers at the locations studied are sensitive to variation of the true Mach number within the test Mach number range of 0.7 to 1.2" (p. 1).
Date: November 3, 1949
Creator: Johnston, J. Ford & O'Bryan, Thomas C.
System: The UNT Digital Library