Following the shutdown of the B Pile in March 1946 a method was devised for monitoring the sub-critical reactivity such that any significant change in neutron flux would be detected. This report summarizes the status of the unit until its start up in July 1948.

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This report covers work done by the Pile Engineering Groups and work done on special assignments. Topics covered include: slug blistering and corrosion; graphite allocation to DR pile; slug molding; segmental discharge; Van Stone corrosion; flow laboratory modifications; downcomer at B pile; downcomer at D pile; annealing of pile graphite; replacement of pile atmosphere with CO{sub 2}; unit motion; beta experiment; can opening; slug annealing; new technical building, 300 area; and ruptured slugs.

Much of the cloud chamber work has been directed toward obtaining the angular distribution of protons bombarded by deuterons from the 184-inch cyclotron. The observations have been restricted to those protons arising from neutrons of energy greater than 65 Mev. The cloud chamber used for this work is of 16-inch diruneter and employs a magnetic field of 14000 gauss. The chamber is filled with hydrogen at a pressure of 1/2 atmosphere; the vapor used is water and alchohol. Nearly 800 proton tracks were measured and calculated before analysis of the data indicated that the measuring procedure should be revised. They gave the angular and energy distributions shown in Figures 1 and 2. The discrepencies between the theoretical and experimental energy distribution of the neutrons shows that serious errors were being made. As a first check of possible sources of error, random parts of the data were remeasured. They indicated that errors in the measurements of the angles were being made that gave a mean deviation of about {+-} 2{sup o} in the beam angle and {+-} 4{sup o} in the dip angle. These errors were largest at large scatter angles. In addition, a more serious error occured in the measurements …

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Report presenting a flight investigation conducted on a rectangular ramjet incorporating a V-shaped gutter-type flame holder over a range of fuel air ratios, combustion chamber inlet velocities, and pressure altitudes.

Report presenting an investigation to correlate the engine service performance of cast Vitallium turbine buckets with standard laboratory metallurgical data. Data was obtained on four turbine wheels of Timken alloy with cast Vitallium buckets. Results regarding the engine test and metallurgical examination are provided.

An investigation of several ejector configurations to determine the ability to handle the air required for engine cooling. The results are limited to investigations of conical-type mixing-section ejectors at ratios of mixing-section minimum diameter to primary-jet-nozzle diameter using unheated air. Results regarding experimental data, generalization of experimental data, spacing for maximum weight-flow ratio, ejector thrust, ejector configurations for constant weight-flow ratio, and selection of ejector design are provided.

"An investigation has been conducted in the Langley 300 MPH 7- by 10-foot tunnel to determine the static stability characteristics at low speeds of complete models with various swept wings so that comparisons might be made with available theoretical and empirical methods of predicting the stability characteristics. Longitudinal and lateral stability characteristics, flaps up and down, were obtained for models having 0 degree, 15 degrees, 30 degrees, and 45 degrees sweptforward and sweptback wings. The results of the investigation indicate that static stability characteristics can be estimated with reasonable accuracy in the low-lift range by means of existing theories" (p. 1).

The results of tests at a Mach number of 1.94 of an ogives-nose cylindrical pitot-static tube and similar tests at Mach numbers of 1.93 and 1.62 of a service pitot-static tube to determine body static pressures and indicated Mach numbers are presented and discussed. The radial pressure distribution on the cylindrical bodies is compared with that calculated by an approximate theory.

Memorandum presenting an investigation in the high-speed 7- by 10-foot tunnel using the transonic bump method to determine the longitudinal stability and control characteristics of a semispan airplane model at transonic speeds. The results indicated an increase in the maneuvering stability through the transonic range, but regions of instability were indicated by the slope of the curve stabilizer incidence for trim against Mach number at all positions tested.

Report presenting drag measurements made on a 10-percent-thick wing and 8-percent-thick tail and a 8-percent-thick wing, 6-percent-thick tail version of the X-1 airplane at a variety of Mach numbers. The drag of the thicker wing was found to be much higher than that of the thinner wing. The fuselage was found to cause interference with the wing of both models, making the separation of wing and fuselage drag difficult to determine.

From Summary: "This report presents the results of a wind-tunnel investigation conducted to determine the effects of Mach number on the aerodynamic characteristics of a wing of triangular plan form."

Report presenting a wind-tunnel investigation at a range of Mach numbers with a constant Reynolds number of a semispan model of a thin, unswept wing of aspect ratio 4 and taper ratio 0.5 with a constant-chord aileron and a modified diamond profile. Results regarding lift and rolling-moment characteristics and aileron effectiveness are provided.

Results are presented of tests up to a Mach number of 0.92 at altitudes around 30,000 feet. The data obtained show that the airplane can be flown to this Mach number above 30,000 feet. Longitudinal trim changes have been experienced but the forces involved have been small. The elevator effectiveness decreased about one-half with increase of Mach number from 0.70 to 0.87.

"An investigation of an NACA submerged air intake was conducted on a full-scale model of a fighter-type airplane. This study was made to determine the large-scale aerodynamic characteristics of a submerged air intake proposed as the result of small-scale tests and to compare the pressure-recovery characteristics of the large- and small-scale installations. Additional tests were made to determine the effect on pressure recovery of a systematic variation of ramp divergence" (p. 1).

Report discussing an investigation of the vertical plane of the elevator hinge line of a powered model of a bomber to determine the values of downwash and the dynamic-pressure ratio. The equations for calculating these values and the testing procedures are described.

Report presenting measurements of the handling qualities of the Bell XS-1 transonic airplane using NACA instruments. Information regarding the stability and control characteristics and aerodynamic loads was obtained using two different airplanes in gliding and powered flight. Results regarding the longitudinal and lateral stability and control and stalling characteristics are provided.

Using an apparatus described in a preceeding paper the reaction rate of the fluorination of UO/sub 2/ by HF was measured under the condition of a gradually increasing temperature. UF/sub 4/ made in this way did not show caking although final reaction temperatures ranged as high as 700 deg C. The rate of reaction was found to be greater than the rate measured under isothermal conditions at the highest temperature attained during the continuous increase as long as this final temperature was above 550 deg C. (auth)

Tests were made with a 1/8-scale dynamically similar model of the Chance Vought XF6U-1 airplane to study its behavior when ditched. The model was ditched in calm water at the Langley tank no. 2 monorail. Various landing attitudes, speeds, and conditions of damage were simulated. The behavior of the model was determined from visual observations, by recording time histories of the accelerations, and by taking motion pictures of the ditchings. From the results of the tests it was concluded that the airplane should be ditched at the near-stall, tail-down attitude (12 deg). The flaps should be fully extended to obtain the lowest possible landing speed. The wing-tip tanks should be jettisoned. The underside of the fuselage will be critically damaged in a ditching and the airplane will dive violently after a run of about three fuselage lengths. Maximum longitudinal decelerations up to about 7g and maximum vertical accelerations up to about 5g will be encountered.

"A Westinghouse 24C-2 combustor was investigated at conditions simulating operation of the 24C Jet engine at zero ram over ranges of altitude and engine speed. The investigation was conducted to determine the altitude operational limits, that is, the maximum altitude for various engine speeds at which an average combustor-outlet gas temperature sufficient for operation of the jet engine could be obtained. Information was also obtained regarding the character of the flames, the combustion efficiency, the combustor-outlet gas temperature and velocity distributions, the extent of afterburning, the flow characteristics of the fuel manifolds, the combustor inlet-to-outlet total-pressure drop, and the durability of the combustor basket" (p. 1).

Domestic franchise tax return of 1947 for Texas Cotton Industries. The return includes all necessary schedules and financial statements.