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.

This brief memo from the 300 area of the Hanford plant, July 13, 1948, describes the need to redesign the ventilation system so as to minimize hazards associated with performing maintenance work.

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From Introduction: "In an incomprehensible medium, the mutual interference of a fuselage and wing of high-aspect ratio (to which lifting-line theory is applicable) has been treated by Lennertz, Wiselsberger, Pepper, and Multhopp in reference 1, 2, 3, and 4. It is the purpose of this note to treat the effect of on the aerodynamic loading of the mutual interference between a low-aspect-ratio pointed wing and a fuselage consisting of a slender body of revolution."

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"An altitude-test-chamber investigation was conducted to determine the operational characteristics and altitude blow-out limits of a Solar afterburner in a 24C engine. At rated engine speed and maximum permissible turbine-discharge temperature, the altitude limit as determined by combustion blow-out occurred as a band of unstable operation of about 8000 feet altitude in width with maximum altitude limits from 32,000 feet at a Mach number of 0.3 to about 42,000 feet at a Mach number of 1.0. The maximum fuel-air ratio of the afterburner, as limited by maximum permissible turbine-discharge gas temperatures at rated engine speed, varied between 0.0295 and 0.0380 over a range of flight Mach numbers from 0.25 to 1.0 and at altitudes of 20,000 and 30,000 feet" (p. 1).

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"A theoretical analysis is presented for obtaining by use of Theodorsen's propeller theory the load distribution along a propeller radius to give the optimum propeller efficiency for any design condition. Examples are included to illustrate the method of obtaining the optimum load distributions for both single-rotating and dual-rotating propellers" (p. 1).

The authors have produced and identified two new series of alpha-particle emitting radioactive elements; one is a 'collateral' branch of the actinium (4n + 3) radioactive family and the other is collateral to the thorium (4n) family. The series are of considerable interest in that they are the first whose early members lie on the neutron deficient side of beta stability. They have been produced in high yield of irradiation of thorium with deuterons of energy about {sup 80}Mev in the Berkeley 184-inch cyclotron. So far as the present observations are concerned both of these series begin with isotopes of protactinium (atomic number 91), although progenitors with higher atomic numbers are to be expected and will possibly be produced and identified. These protactinium isotopes are Pa{sup 227} and Pa{sup 228} formed by d,7n and d,6n reactions respectively.

The following document describes some studies of the radioactive isotopes of cerium and lanthanum lying on the light or neutron-deficient side of stability.

"A bibliography of NACA papers on rotating-wing aircraft issued up to July 1948 is presented. The list of papers is subdivided for ready reference under appropriate subject headings, and the titles are listed chronologically within each subject" (p. 1).

"A series of calculations of the dynamic response of airplane wings to gusts were made with the purpose of showing the relative response of a reference airplane, the DC-3 airplane, and of newer types of airplanes represented by the DC-4, DC-6, and L-49 airplanes. Additional calculations were made for the DC-6 airplane to show the effects of speed and altitude. On the basis of the method of calculation used and the conditions selected for analysis, it is indicated that: 1) The newer airplanes show appreciably greater dynamic stress in gusts then does the reference airplane; 2) Increasing the forward speed or the operating altitude results in an increase of the dynamic stress ratio for the gust with a gradient distance of 10 chords" (p. 1).

Note presenting a theoretical analysis of the characteristics of constant-chord full-span control surfaces on thin triangular wings at supersonic speeds by use of methods based on the linearized equation for supersonic flow. Expressions were found for the lift effectiveness, pitching-moment coefficient, hinge-moment coefficient due to control deflection, and hinge-moment coefficient due to angle of attack.

Report presenting a theoretical analysis of the characteristics of constant-chord partial-span control surfaces on thin triangular wings at supersonic speeds by use of methods based on the linearized theory for supersonic flow. Two cases were treated with the analysis. Results regarding lift coefficient, rolling-moment coefficient, and hinge-moment coefficient due to flap deflection, hinge-moment coefficient due to angle of attack, and the pitching-moment coefficient due to flap lift.

Contains charts for use in determining preliminary values of the spanwise-load, shear, bending-moment, and accumulated-torque distributions of swept wings. The charts are based on strip theory and include four aerodynamic-load distributions, two section-moment distributions, and two inertia-load distributions. The taper ratios considered cover the range from 1.0 to 0 and the results are applicable to any angle of sweep.

Charts are provided for the estimation and progressive adjustment of two independent variables on which the calculations are based. Additional charts are provided for the graphical calculation of the composition.

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"The theoretical critical stress is derived for a simply supported curved rectangular panel in axial compression having a central chordwise stiffener offering no torsional restraint. The results are presented in the form of computed curves and a table. Because a panel of moderate or large curvature buckles in compression at a stress considerably below the theoretical value, a method is suggested to aid in determining the critical stress for use in design" (p. 1).

The initial phase of the pressure drop testing program on proposed fuel element design shapes for the high-temperature, gas-cooled power reactor, has been completed with the compilation of pressure drop data for the flatplate riveted-assembly type of unit, the ribbed cylinder type, the single bent-plate type both with and without rivets, the 13 hexagon-6 pentagon type, and the 7-hole graphite type. This phase of the program was conducted for the purpose of determining the equivalent skin-friction pressure drop factor for composite fuel element crosssections, and for determining the joint loss factors for varying degrees of misalignment of the fuel units in the fuel channels of the pile. (auth)

Note presenting a device that measures the velocity of sound in fluids at stagnation and is especially adaptable to turbine and compressor testing for which the composition of the working fluid may be in doubt. The Helmholtz resonator is used for measuring sonic velocity and compressor Mach number in these devices.

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.

Wind-tunnel tests of a simplified nacelle on a semispan wing having approximately 35 degrees of sweepback were made at low speeds to evaluate the effects of the nacelle on the aerodynamic characteristics of the wing. Force, moment, and pressure-distribution measurements are presented for the nacelle underslung and centrally mounted on the wing and mounted on a strut below the wing.

Report presenting an investigation with a ram-jet combustion chamber to determine the effect of fuel-air ratio and the inlet-air parameters of pressure, temperature, and velocity on combustion limit, combustion efficiency, and flame length.

Note presenting an experimental investigation at low airspeeds of the filling effect observed when a screen or similar resistance is placed across a diffuser. The filling effect is found to be real in that screens can prevent separation or restore separated flow in diffusers even of extreme divergence and to depend principally on screen location and pressure-drop coefficient of the screen.