"Existing data on the errors involved in the measurement of static pressure by means of static-pressure tubes and fuselage vents are presented. The errors associated with the various design features of static-pressure tubes are discussed for the condition of zero angle of attack and for the case where the tube is inclined to flow. Errors which result from variations in the configuration of static-pressure vents are also presented" (p. 645).

From abstract: "Scattering cross sections have been computed for zero-energy neutrons incident upon a square well of spheroidal symmetry, depth 42 Mev, and volume equal to that of a sphere of radius 1.45 x 10⁻¹³ ^1/3 cm."

Report issued by the Oak Ridge National Laboratory discussing semiannual progress made by the Solid State Division during 1956. Descriptions of progress and studies made are presented. This report includes tables, illustrations, and photographs.

Abstract: And investigation of the interactions between 300-Mev neutrons and xenon was made by means of a cloud chamber in a pulsed magnetic field of 21,700 gauss placed in the neutron beam of the 184-inch Berkeley cyclotron. Eighty-seven negative pion events and 257 other stars were analyzed. In addition an experimental check was made on the energy of the incoming neutrons. Classification, identification, and angular and energy distributions of prongs associated with all events are presented. Interpretations of results are given.

Report consisting of a summary and papers covering the activities occurring during the year 1956 in the National Advisory Committee for Aeronautics. The paper is broken up into letter of transmittal, letter of submittal, the technical activities, committee organization and membership, and the financial report.

"Merging of the subsonic diffuser and the combustor appears feasible with a highly reactive fuel such as hydrogen. At typical ram-jet operating to be stabilized at velocities of 600 feet per second by means of a fuel injector alone. Thus it was possible to seat the flame at a station where the Mach number was 0.4 to 0.5 rather than 0.2 as is done conventionally" (p. 1).

In the Columbia River downstream from Richland, Washington there is a gradual decrease in concentration of radioactive isotope. At any one location there are fluctuations due to factors such as dilution and decay time. During this period at all locations the concentration of alpha particle emitters in water averaged below the detection limit. Beta particle emitters in water upstream of McNary Dam decreased slightly due to increased river flow this quarter, with averages at various locations. Downstream from McNary Dam, beta particle emitter average concentrations in water were about the same as the past three quarters.

Hydrogen peroxide has been used to reduce plutonium (VI) in nitric acid solution to the (IV) valence state. However, reduction of plutonium (VI) solutions containing iron has often been incomplete when hydrogen peroxide was used as the reducing agent. Since reduction of plutonium (VI) has been applied in plant solutions containing iron, a study of the plutonium (VI) reduction with hydrogen peroxide was undertaken. Variables tested included plutonium, nitric acid, and iron concentrations.

The creep problems associated with zircaloy-2 process tubes and the factors affecting the creep of these tubes were discussed in detail. Emphasis was placed on the determination of the tube wall thickness for an SPR tube, whose minimum thickness is limited by creep considerations. It was concluded that, at the present time, there is not enough information available to design zircaloy-2 process tubes on a realistic basis. Various experiments were suggested to supplement the creep rate testing program being pursued by Battelle Memorial Institute.

Abstract: "Uranium monocarbide-Zircaloy II alloy cermets were developed and tested for chemical and physical properties. It was determined that pure uranium monocarbide can be prepared by vacuum are melting techniques. Following melting, the combination, hot pressing, and corrosion behavior of dense monocarbide has been studied. The preparation of uranium monocarbide-Zircaloy II cermet bodies was investigated by means of hot pressing, cold pressing and sintering, warm pressing, extrusion, and hot rolling. The corrosion resistance of the cermets was related to such variables as composition, preparation technique, and powder size. 01 per cent uranium monocarbide, 70 per cent zircaloy II cermets withstood corrosion tests in 680 F water. Cermets having above 30 weight per cent uranium monocarbide were not corrosion resistant."

"Compressible and incompressible flow calculations were made of the combustor total-pressure-loss coefficient and liner airflow distribution for tubular turbojet combustors having constant annulus and liner cross-sectional areas along the combustor axis. Information on static and total pressure distribution and liner air-jet entrance angles along the length of the combustor was obtained as an intermediate step in the calculations. The calculations include the effects of heat release, annulus wall friction, and variation in discharge coefficients of the liner wall openings along the combustor" (p. 899).

Report presenting two low-solidity configurations tested to provide data on the effects of solidity on overall and blade-element performance. Results regarding weight flow, pressure ratio, and efficiency, stall characteristics, rotor-inlet conditions, total-pressure ratio, work coefficient, and efficiency are provided.

Performance data are presented for a transonic axial-flow compressor rotor designed to operate at a tip speed of 1300 ft/sec with maximum relative tip Mach number of 1.37. The compressor had an inlet diameter of 16 inches, a hub-tip diameter ratio of 0.5 and design specific weight flow of 31.1 (lb/sec/(sq ft frontal area). Experimental values of relative total-pressure-loss coefficient were considerably higher than the assumed values. This disparity, hub choking, and application of the simple radial-equilibrium concept are discussed.

Report presenting force tests of a 0.10-scale model of the Douglas A4D-1 airplane in the 8-foot transonic pressure tunnel to investigate the static longitudinal characteristics of wing and fuselage modifications and the static lateral characteristics of the basic model. Tests were conducted over a range of Mach numbers and angles of attack.

Smoke was used to visualize outer-wall secondary flows in a low-speed turbine utilizing rotor tip air discharge and suction. Photographs as well as visual observations of the effect of tip air discharge and suction were made by independently varying the direction and quantity of the tip air discharge and suction, and varying tip clearance, and main-stream air speed. In addition, the cross-sectional area of the hollow blade discharge opening was varied for the case of tip air discharge.

Report presenting the suggestion of an engine configuration that is intended to minimize difficulties caused by exhaust products that are expected to adhere to stationary parts but not rotating parts and exploit the high reactivity of fuel. Component efficiencies of the engine are assigned and its performance is compared with that of a single-stage turbine engine. Results regarding the effect of reaction-nozzle-jet angle, effect of turbine-exit axial Mach number, comparison of rotojet and turbojet performance, and performance of fixed-geometry rotojet engine are provided.

Force and moments were measured for the XV-1 convertiplane at 75 to 150 knots. Rotor on and off and propeller powered and off configurations were investigated. The characteristics of the V-tab horizontal tail and its downwash field were studied. Lift interference between fixed wing and rotor and possible means of drag reduction were considered.

Report presenting an investigation of the use of aerodynamic and mechanical devices for improving the response of guided missiles. An analysis indicates that the use of free-floating flaps and spring-mounted control surfaces should be able to increase maneuverability to the point that electronic automatic stabilization and gain-adjusting devices can be eliminated.

Report presenting investigations of the effect of air injection at the stagnation point on the heat-transfer characteristics of a hemisphere in a supersonic stream. Results regarding air injection directly into the stream and air injection tangent to surface are provided.

Report presenting a study of the potentially large violent coupled motions encountered by the Douglas X-3 in flight. Testing indicated that the motions encountered appeared to be caused by the inclination of the principal axis below the flight path at the onset of rolling maneuvers and the existence of pitching moment due to side slip combined with a trim change near Mach number 1. Results regarding the effect of principal-axis inclination, effect of changes in directional stability, effect of pitching moment due to sideslip, effect of trim changes, and effect of roll direction are provided.

Report presenting an investigation to determine the vertical-tail loads and airplane characteristics in sideslip for a model of a swept-wing fighter-type airplane in the 16-foot transonic tunnel at a range of Mach numbers and angles of attack. Results regarding the effect of the unsealed vertical-tail root on airplane coefficients, directional and lateral stability, vertical-tail loads, effect of leading-edge chord-extensions on lateral and directional characteristics and on tail loads, and pitching moments in sideslip are provided.

The experimental evaluation of low (10⁻⁸ in/in/hr) creep rates are costly and time consuming. Thus, in answer to a request from the design group, the creep data on Zircaloy-2 obtained at Battelle Memorial Institute is extrapolated into the low creep rate range. Because the methods of extrapolation have not been evaluated at very low creep rates on Zircaloy, two different methods are used to analyze the creep data. The methods of extrapolation are given so that future analyses can be carried out by the design group or by other sections interested in predicting creep rates which have not been experimentally determined.

"A negligible effect on turbine efficiency and only a small decrease in turbine weight flow were observed when the J71 experimental turbine with 97-percent-design stator areas was modified to include shrouding of the third-stage rotor" (p. 1).

An experimental invesitgation of the effect of increasing the first-stator area of the J71-97 experimental three-stage turbine from 97 percent of design to 132 percent revealed (1) the maximum efficiency obtained decreased from 0.891 to 0.869, (2) the choking equivalent weight flows increased by approximately 13.6 percent, and (3) at the turbine match points required to maintain the compressor at constant design equivalent conditions the turbine efficiency decreased from 0.87 to 0.86.