Quarterly report documenting progress on a project to determine an improved zirconium alloy for service in superheated water and steam. This report describes the results of approximately 75 compositions that were prepared prior, and presently are being arc-melted and fabricated into corrosion specimens, continuing the investigations of the effect of zirconium purity and heat treatment on corrosion and resistance.

The following report focuses on an investigation made to determine if vacuum melting was an absolutely necessary step in the metallurgical process of melting and casting uranium.

The need for special high velocity shock testing is pointed out and equipment that has been developed to meet these needs is discussed. The concept of velocity-change and its importance in shock-testing technology is brought out. The three types of equipment discussed are: accelerated drop testers, pneumatic actuators, and air guns. Examples of each type and their capabilities and limitations are presented.

"Flight icing-rate data obtained in a dense and abnormally deep supercooled stratiform cloud system indicated the existence of liquid-water contents generally exceeding values in amount and extent previously reported over the midwestern sections of the United States. Additional information obtained during descent through a part of the cloud system indicated liquid-water contents that significantly exceeded theoretical values, especially near the middle of the cloud layer. The growth of cloud droplets to sizes that resulted in sedimentation from the upper portions of the cloud is considered to be a possible cause of the high water contents near the center of the cloud layer" (p. 1).

Report presenting an investigation conducted to determine the overall performance of the J73 two-stage turbine with a standard rotor-blade configuration. The turbine operated with a maximum brake internal efficiency between 0.91 and 0.92 at an overall pressure ratio of about 3.4 and 120 percent equivalent design rotor speed. Results regarding the overall performance, variation of equivalent weight flow with overall pressure ratio, and effect of limiting blade loading are provided.

Report presenting flight measurements of aerodynamic tail loads made on the Douglas D-558-II from which the variation with Mach number of the wing-fuselage aerodynamic center, static-longitudinal-stability parameter, the tail load per g, and the zero-lift wing-fuselage pitching-moment coefficient determined up to Mach number 0.87.

From Summary: "Force characteristics determined from tank tests of a 1/5.78-scale model of a hydro-ski-wheel combination for the Grumman JRF-5 airplane are presented. The model was tested in both the submerged and planing conditions over a range of trim, speed, and load sufficiently large to represent the most probable full-size conditions."

Report presenting a wind-tunnel investigation to determine the effects of two wing-root leading-edge plan-form modifications, including a notched leading-edge fillet and a rounded leading-edge fillet, on the low-speed longitudinal stability characteristics of an airplane model with a 50.7 degree sweptback wing. Results regarding stability at zero lift, variation of stability with lift coefficient, and lift and drag characteristics are provided.

Report presenting an investigation at transonic speeds to determine the control characteristics of a linked flap and spoiler. The control consisted of a linked combination of a quarter-span inboard plug-type spoiler and a full-span flap. Results regarding the hinge-moment, pitching-moment, lift, and rolling-moment are provided.

Report presenting an investigation using the NACA wing-flow method at transonic speeds to determine the contributions of wing, tail, and fuselage to the aerodynamic characteristics of a semispan airplane model with a long slender fuselage and straight wing and tail of low aspect ratio with faired symmetrical double-wedge airfoil sections 4.6 percent of the chord in thickness. Results regarding the drag, pitching moment, downwash, and lift are provided.

Report presenting an investigation to determine the feasibility of utilizing a reduced-chord rotor blading on the two-stage turbine of the J73 turbojet engine in order to reduce the weight. The turbine was operated as a component over a range of speeds and overall pressure ratios at turbine-inlet conditions corresponding to 35 inches of mercury absolute and 700 degrees R. Results regarding the overall performance, performance map, and peak efficiency are provided.

"The effect of several parameters on the drag characteristics of practical-construction wing sections have been considered and evaluated. The effects considered were those of surface roughness, surface waviness, compressive load, and de-icers. The data were obtained from a number of tests in the Langley two-dimensional low-turbulence tunnels" (p. 359).

Report presenting an evaluation of the stage performance of the J73 turbine on the basis of previous performance investigations of the first stages alone and of the two-stage turbines with standard and with reduced-chord rotor blading for a range of rotational speeds and pressure ratios. The results demonstrated that both of the two-stage turbines and first-stage turbines had comparable performance.

Report presenting an investigation in the 4- by 4-foot supersonic pressure tunnel to determine the static longitudinal stability and control characteristics of a model of a 45 degree swept-wing fighter airplane at three Mach numbers. The results indicate that the static margin, which was fairly constant through the lift range, decrease from 32 to 27 percent mean aerodynamic chord with increase in Mach number from 1.41 to 2.01.

From introduction: "On February 1, 1956, Batelle was awarded a contract by the Army Reactor Branch (ARB) to select, develop, and test core materials which could be used successfully in conducting a Gas Cooled Reactor Experiment (GCRE). The prime objective of the GCRE would be to evaluate small portable reactor systems for military application...The present report is concerned with the GCRE activities at Batelle during approximately the 7 months' period following the first report of this series, BMI-1133. It is primarily concerned with a detailed evaluation of the reference materials as well as of the impact of one material upon the other."

Report discussing a method of evaluating factors relevant to the creation of sound uranium castings. From abstract: "A mathematical model has been developed to calculate the time-temperature relationships in a cylindrical uranium casting during its solidification. Finite-difference equations are used, and the solution is obtained by use of a digital computer."

From introduction: "In order to locate systematic trends of states with a certain angular momentum and parity Jπ in nuclei having constant neutron excess, both the ground state and the level energies will be considered simultaneously: we plot the total nuclear binding energy or nuclidic mass excess of excited states, whereby the ground states appear as a special case. Such a natural correlation of level schemes has been employed before Inglis already in 1953."

Many measurement of neutron spectra have been made in water assemblies. In these system a large part of the spectrum is given by an essentially Maxwellian distribution at the moderator temperature which is insensitive to the scattering model. Hence, the test of the energy exchange scattering kernel is in the difference of the spectrum and the fundamental or Maxwellian component. The figure shows the spectrum for the Nelkin model. Once the fundamental has been subtracted neither theoretical model seems to fit the data extremely well. Below kT the Nelkin model is a closer fit than the gas model but it underestimates the deviation from the Maxwellian whereas in the joining region it overestimates the distortion.

Report describing the Hanford Laboratory controlled potential coulometer. This includes the theory behind the coulometer, details of its circuitry, and performance tests. Appendix begins on page 23.

Memorandum presenting a flight investigation of the Bell X-5 variable-sweep research airplane in the 45 degree wing sweptback configuration over a range of Mach numbers. Lift and drag values are presented and a comparison is made with data obtained with a wing sweepback of 59 degrees.

Report presenting vibratory stress measurements on a supersonic-type propeller for forward Mach number up to 0.95. Results regarding the bending stress and torsion stress are provided.

The J33-A-27 compressor was operated at an inlet pressure of 14 inches of mercury absolute and ambient inlet temperature over a range of equivalent impeller speeds from 6100 to 11,800 rpm. At the design equivalent speed of 11,800 rpm, the J33-A-27 compressor had a peak pressure ratio of 4.40 at an equivalent weight flow of 105.7 pounds per second and a peak adiabatic temperature-rise efficiency of 0.745. The maximum equivalent weight flow at design speed was 113.5 pounds per second.

"The multistage turbine from the J73 turbojet engine has previously been investigated with standard and with reduced-chord rotor blading in order to determine the individual performance characteristics of each configuration over a range of over-all pressure ratio and speed. Because both turbine configurations exhibited peak efficiencies of over 90 percent, and because both units had relatively wide efficient operating ranges, it was considered of interest to determine the performance of the first stage of the turbine as a separate component. Accordingly, the standard-bladed multistage turbine was modified by removing the second-stage rotor disk and stator and altering the flow passage so that the first stage of the unit could be operated independently" (p. 1).

Memorandum presenting system analyses and autopilot design procedure for a supersonic pilotless aircraft with twin jet engines. The autopilots investigated were a gyro-actuated control, a gyro-actuated control with a rate-sensing device, and an electronic-hydraulic autopilot. Results regarding the airframe and gyro-actuated control system; airframe, gyro-actuated control, and rate servo; airframe and electronic-hydraulic autopilot; and contribution of method of analysis to system design are provided.