The following report presents a discussion of the method for hydrodynamic problems, together with some new considerations that have arisen concerning the method.

Abstract: "From neutron-yield measurements made with a MnSO4 detecting solution, the average number of neutrons produced per inelastic event is determined for a series of elements from lithium to uranium for 340-Mev protons, 190-and 315-Mev deuterons, 490-Mev He3 ions, and 90- and 160-Mev neutrons. The results are analyzed in an attempt to understand the total yield measurements for thick targets and to explain the variation of yield with the atomic number of the target."

"An experiment to determine the effect of reactor irradiation on the thermal conductivity of uranium-impregnated graphite at elevated temperatures as described. The results show a decrease in the thermal conductivity saturating at [approximately] 60 percent at a temperature of 700 degrees C; at [approximately] 50 percent at a temperature of 1000 degrees C; and at [approximately] 25 percent at a temperature of 1300 degrees C. It was found that after irradiation at a given temperature, exposure at a higher temperature resulted in an increase in the thermal conductivity. The converse was also observed. Within the precision of measurement there was no difference in effed between temperature changes produced by varying the fission rate in the samples and changes produced by varying the power in an external heater."

Report presenting an investigation to determine the pressure drag of various blunt-based conical afterbodies at a range of Mach numbers. A generalized series of bodies was included which incorporated convergent nozzles discharging unheated jets at various pressures from the base. Results regarding the afterbodies without the jet and afterbodies with the jet are provided.

Memorandum presenting the design of a piloted combustor intended for a ramjet engine of long flight range. The unit comprises a large annular basket of V-type cross section, the inner surface of which is slotted and bent into small V-gutters.

Report discussing the characteristics of the fuel control of the 48-inch diameter WRJ47-W-5 ramjet engine, including the time history of the fuel system pressures, fuel flow, and engine inlet total pressure. Oscillograph traces for the different variables are provided as well as the accuracy of the calibration factors.

Report presenting a flight investigation using a rocket-powered model to evaluate the roll-rate stabilization of the Naval Ordnance Test Station SIDEWINDER missile, which uses aerodynamic damping by gyro-actuated rollerons. Dynamic roll instability was found to occur in flight.

Report presenting an investigation of a shock-positioning control on a 16-inch ramjet engine at a range of Mach numbers and angles of attack in the supersonic wind tunnel. The control operated at all conditions under which the engine could be manually operated. Prediction of the control-system dynamic behavior can be applied by treating the system as having pure dead time.

Report discussing a flight test on a rocket-boosted canard aircraft with 60 degree delta lifting surfaces, twin normal-shock-type side inlets, and twin vertical tails. The drag, longitudinal stability, and duct performance data were obtained for a range of Mach and Reynolds numbers.

The report describes the design of a piloted combustor intended for a ram-jet engine of long flight range. The unit comprises a large annular basket of V-type cross-section, the inner surface of which is slotted and bent into small V-gutters. At the trailing edge of the basket, eight V-gutters are used to propagate the flame into the main stream. A rectangular analog of this combustor was tested at air-flow conditions corresponding to those that might be obtained during cruise.

Report presenting longitudinal trim and drag at low lift of the North American YF-100A airplane at a range of Mach numbers as obtained with rocket-propelled models for an airplane, with the horizontal tail removed, and with wing removed conditions. Results regarding drag, longitudinal trim, longitudinal stability, and flutter and buffet are provided.

Report presenting a flight investigation over a range of Mach numbers to determine the aerodynamic characteristics at low lift of a rocket model of an airplane with a 52.5 degree delta wing of aspect ratio 3.08 and NACA 65A003 airfoil sections in the streamwise direction and a low, swept horizontal tail. Results regarding the longitudinal trim, lift, drag, longitudinal static stability, damping in pitch, and directional static stability are provided.

Report presenting an investigation in the high-speed tunnel to determine the effects on the chordwise pressure and section force and moment coefficients near midspan of deflecting a flap-type control with an attached tab on a swept wing. The semispan 35 degree sweptback wing had an NACA 65A006 airfoil section, an aspect ratio of 4, and a taper ratio of 0.6.

Memorandum presenting a study of two jet-noise-suppression devices consisting of teeth projecting into the jet stream was conducted on a current axial-flow turbojet engine. The sound fields obtained with the toothed devices showed a slight reduction in maximum sound pressure level, compared with the sound field from a standard nozzle.

Report presenting an investigation of the screeching characteristics of two flame-holder configurations in a full-scale transpiration-cooled afterburner. The investigation indicated that a porous wall of wire cloth may be effective in eliminating or reducing the tendency to screech in some high-performance afterburners, but further testing is required. Results regarding the diametrical V-gutter, single-ring V-gutter, and durability of wire cloth are provided.

Report presenting drag and longitudinal trim characteristics at low lift of a low-tail version of the North American YF-100A airplane as obtained from the flight test of a 0.11-scale rocket model at a range of Mach numbers. Longitudinal stability data and some qualitative damping-in-pitch data are also provided.

Abstract: The silicides of Ti, Zr, Ce and Nb were investigated to determine the phases present at temperatures around 2000 K. The reactions of silicides of Ti, Zr, Ce, Nb, Ta, Mo, and W with carbon were studied at these temperatures. Also a limited amount of work was done on the reactions of some of the silicides with nitrogen. The data have been used to establish ternary phase diagrams for the systems and to obtain upper and lower limits for the heats of formation of the silicides.

From introduction: "As a part of this program, this report presents the results of a study of an interacting system in which the conditions for criticality are given in terms of the concentration of fissionable material and the geometry of the system."

A report regarding many uranium production plants constructed during the existing emergencies and pressures of World War II that were not intended to be permanent instillations. These plants either contractor or government owned, with buildings on the most part belonging to the contactor and a major portion of the processing equipment belonging to the government, became outmoded with the development

The following quarterly report covers the period between April, May and June of 1954. The reports presented in this document discusses subjects of medical health and physics such as: biological studies of radiation effects, the metabolic properties of various tracer materials, radiation chemistry, health chemistry, and health physics.

Report presenting experiments conducted on conical convergent-divergent nozzles having included a range of divergence angles and expansion ratios over a wide range of nozzle pressure ratios with cold flow to determine the effect of divergence angle on the internal performance of the nozzles. Results regarding the performance characteristics, effect of divergence angle on overexpanded performance, and effect of divergence angle on nozzle air-flow characteristics are provided.

The first four stages were found to cause a major part of the poor low-speed efficiency of this compressor. The low design-speed over-all pressure ratio at surge was caused by the first and the twelfth to fifteenth stages. The multiple over-all performance curves in the intermediate-speed range were at least partly the result of double-branched characteristic curves for the third and seventh stages.

Report presenting an investigation of a shock-positioning control on a 16-inch ramjet engine at a range of Mach numbers and angles of attack in a supersonic wind tunnel. The static-pressure rise across the inlet normal shock was utilized in setting the diffuser at its critical condition. Results regarding the sensing pressures, engine performance, control set engine operation, pressure data, operation of the control during Mach number change, and other applications of control are provided.

An investigation of a 1/14-scale dynamically similar model of a panto-base version of the Chase C-123 airplane was conducted to evaluate the hydrodynamic characteristics of the airplane. The resistance, longitudinal stability, and spray patterns during take-off and general behavior in calm- and rough-water landings were determined. Brief calm-water tests were made to compare the initial vertical impact accelerations of the model with and without hydro-skis. Take-off stability was satisfactory for calm-water operation. A ratio of gross load to maximum resistance of 3,6 was obtained. Heavy spray reached the propellers only during ski emergence. The landing behavior in calm water and in waves 3 feet by 150 feet (full scale) was satisfactory for a normal range of trim angles. Initial impacts in calmwater landings resulted in vertical accelerations of about 2 1/2 with the hydro-skis installed and about 4g with the hydro-skis removed,.