Design and test of mixed-flow impellers 8: comparison of experimental results for three impellers with shroud redesigned by rapid approximate method (open access)

Design and test of mixed-flow impellers 8: comparison of experimental results for three impellers with shroud redesigned by rapid approximate method

Report presenting a comparison of three centrifugal impellers with parabolic, circular, and skewed-parabolic blading that were modified using a recently developed design procedure to reduce velocity gradients along the hub from inlet to outlet. All of the original dimensions except for the shroud contours were retained. Results regarding a comparison of the original and modified parabolic-bladed, circular-bladed, and skewed-parabolic bladed impeller are provided.
Date: February 27, 1957
Creator: Osborn, Walter M.; Smith, Kenneth J. & Hamrick, Joseph T.
System: The UNT Digital Library
Stall Characteristics Obtained from Flight 10 of Northrop X-4 No. 2 Airplane (USAF No. 46-677) (open access)

Stall Characteristics Obtained from Flight 10 of Northrop X-4 No. 2 Airplane (USAF No. 46-677)

NACA instrumentation has been installed in the X-4 airplanes to obtain stability and control data during the acceptance tests conducted by the Northrop Aircraft Corporation. This report presents data obtained on the stalling characteristics of the airplane in the clean and gear- down configurations. The center of gravity was located at approximately 18 percent of the mean aerodynamic chord during the tests. The results indicated that the airplane was not completely stalled when stall was gradually approached during nominally U accelerated flight but that it was completely stalled during a more abruptly approached stall in accelerated flight. The stall in accelerated flight was relatively mild, and this was attributed to the nature of the variation of lift with angle of attack for the 001-614 airfoil section, the plan form of the wing, and to the fact that the initial sideslip at the stall produced (as shown by wind-tunnel tests of a model of the airplane) a more symmetrical stall pattern.
Date: February 27, 1950
Creator: Sadoff, Melvin & Sisk, Thomas R.
System: The UNT Digital Library
Infrared Radiation From Explosions in a Spark-Ignition Engine (open access)

Infrared Radiation From Explosions in a Spark-Ignition Engine

This report presents the results of an investigation to determine the variations in intensity and spectral distribution of the radiant energy emitted by the flames during normal and knocking explosions in an engine. Radiation extending into the infrared was transmitted by a window of fluorite, placed either near the spark plug or over the detonation zone at opposite ends of the combustion chamber. Concave, surface-silvered mirrors focused the beam, first at the slit of a stroboscope which opened for about 2 degrees of crank angle at any desired point in the engine cycle, and then upon the target of a sensitive thermocouple for measuring radiation intensity.
Date: February 27, 1934
Creator: Marvin, Charles F., Jr.; Caldwell, Frank R. & Steele, Sydney
System: The UNT Digital Library
Summary of the Stratigraphy, Sedimentology, and Mineralogy of Pennsylvanian and Permian Rocks of Oklahoma in Relation to Uranium-Resource Potential (open access)

Summary of the Stratigraphy, Sedimentology, and Mineralogy of Pennsylvanian and Permian Rocks of Oklahoma in Relation to Uranium-Resource Potential

Report describes the structural and stratigraphic framework, depositional environment, and petrology and petrography of the various Pennsylvanian-Permian time and rock units present in Oklahoma. This report identifies five geologic settings favorable for the localization of uranium, such as alluvial fan deposits, oil-productive structures where Permian sandstones are altered, tidal-flat sandstone-silstones, channel sandstones on gentle structural features, and oil-productive Cherokee sandstones.
Date: February 27, 1976
Creator: Shelton, John W. & Al-Shaieb, Zuhair
System: The UNT Digital Library