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Transistorization of Nuclear Counting Circuits

Description: From Abstract: "The advantage of long operational life, low power drain and miniaturization may be realized in nuclear counting circuits through the use of transistors. The disadvantage of instability, due to the effects of temperature change in the transistor, may be minimized in counting circuit designs. Representative circuits of a binary stage, amplitude discriminator, one shot multivibrator, and ratemeters are included. These were designed using the criteria of an minimum Beta and a maximum Ico."
Date: August 19, 1957
Creator: Graveson, R. T. & Sadowski, H.

Investigation of Porous Gas-Heated Leading-Edge Section for Icing Protection of a Delta Wing

Description: A tip section of a delta wing having an NACA 0004-65 airfoil section and a 600 leading-edge sweepback was equipped with a porous leading-edge section through which hot gas was 'bled for anti-icing. Heating rates for anti-icing were determined for a wide range of icing conditions. The effects of gas flow through the porous leading-edge section on airfoil pressure distribution and drag in dry air were investigated. The drag increase caused by an ice formation on the unheated airfoil was measured for several icing conditions. Experimental porous surface- to free-stream convective heat-transfer coefficients were obtained in dry air and compared with theory. Adequate icing protection was obtained at all icing conditions investigated. Savings in total gas-flow rate up to 42 percent may be obtained with no loss in anti-icing effectiveness by sealing half the upper-surface porous area. Gas flow through the leading-edge section had no appreciable effect on airfoil pressure distribution. The airfoil section drag increased slightly (5-percent average) with gas flow through the porous surface. A heavy glaze-ice formation produced after 10 minutes of icing caused an increase in section drag coefficient of 240 percent. Experimental convective heat-transfer coefficients obtained with hot-gas flow through the porous area in dry air and turbulent flow were 20 to 30 percent lower than the theoretical values for a solid surface under similar conditions. The transition region from laminar to turbulent flow moved forward as the ratio of gas velocity through the porous surface to air-stream velocity was increased.
Date: January 19, 1955
Creator: Bowden, Dean T.

Wind-tunnel investigation of the descent characteristics of bodies of revolution simulating anti-personnel bombs

Description: An investigation has been conducted in the Langley 20-foot free spinning tunnel to study the relative behavior in descent of a number of homogeneous balsa bodies of revolution simulating anti-personnel bombs with a small cylindrical exploding device suspended approximately 10 feet below the bomb. The bodies of revolution included hemispherical, near-hemispherical, and near-paraboloid shapes. The ordinates of one near-paraboloid shape were specified by the Office of the Chief of Ordnance, U. S. Army. The behavior of the various bodies without the cylinder was also investigated. The results of the investigation indicated that several of the bodies descended vertically with their longitudinal axis, suspension line, and small cylinder in a vertical attitude,. However, the body, the ordinates of which had been specified by the Office of the Chief of Ordnance, U. S. Army, oscillated considerably from a vertical attitude while descending and therefore appeared unsuitable for its intended use. The behavior of this body became satisfactory when its center of gravity was moved well forward from its original position. In general, the results indicated that the descent characteristics of the bodies of revolution become more favorable as their shapes approached that of a hemisphere.
Date: December 19, 1951
Creator: Sher, S. H.

A Method for Prevention of Screaming in Rocket Engines

Description: Lateral and longitudinal combustion-pressure oscillations that occurred in screaming combustion of a 1000-pound-thrust rocket engine using white fuming nitric acid and JP-4 fuel as propellants were successfully prevented by means of longitudinal fins in the combustion chamber. Fin position was critical, and complete attenuation was achieved only when the fins were located in a zone approximately 8 to 16 inches from the injector. Fins located in other zones, that is, near the injector or far downstream from the injector, did not stop the oscillations. When oscillations occurred in finned chambers, the longitudinal mode seemed more dominant than the lateral mode; in chambers without fins, the lateral mode tended to be dominant. The lateral oscillation was distorted and its intensity diminished by the fins. Fins, however, did not affect the frequencies; the longitudinal frequency varied inversely with chamber length, and lateral frequencies varied only slightly from an average of 6000 cycles per second.
Date: August 19, 1954
Creator: Kerslake, W. R. & Male, T.

An Investigation at Low Speed of the Spin Instability of Mortar-Shell Tails

Description: An investigation was made in the Langley stability tunnel to study the influence of number of fins, fin shrouding, and fin aspect ratio on the spin instability of mortar-shell tail surfaces. It was found that the 12-fin tails tested spun less rapidly throughout the angle-of-yaw range than did the 6-fin tails and that fin shrouding reduced the spin encountered by a large amount.
Date: June 19, 1957
Creator: Bird, John D. & Lichtenstein, Jacob H.

Altitude chamber evaluation of an aircraft liquid hydrogen fuel system used with a turbojet engine

Description: From Introduction: "The objective of this report are (1) to describe the complete fuel system, (2) to discuss the procedure used for transitions between JP-4 fuel and hydrogen, and (3) to present and discuss engine performance obtained with both fuels, and (4) to review the reliability of the fuel system."
Date: August 19, 1957
Creator: Algranti, J. S.; Braithwaite, W. M. & Fenn, D. B.

Some effects of roll rate on the longitudinal stability characteristics of a cruciform missile configuration as determined from flight test for a Mach number range of 1.1 to 1.8

Description: Report discussing testing of a cruciform missile with a low-aspect-ratio wing and flap-type controls to determine the stability and control characteristics while rolling. Longitudinal stability and control effectiveness for this particular configuration were examined. The data obtained was compared to results from a similar model that was rolling significantly less.
Date: June 19, 1956
Creator: Lundstrom, Reginald R. & Baber, Hal T., Jr.