This is the third quarterly report that documents a system of mass flow that can record measurements of homogeneous flow, slurries, highly corrosive fluids and multiphase fluids, additionally considering pressure drops, measuring external to the flow, ruggedness and reliability.

Technical report outlining the determination of the effective resonance integral for U238 as a function of the mass ratio for cylinders of 5/8" to 3" diameter. Also gives a linear approximation of the effective resonance integral with infinite shielding in the form of a function. [From Abstract]

Report discussing testing to determine the cooling effect of modified baffles and auxiliary-cooling ducts on the rear-row cylinders of a double-row radial engine. The modified baffles were found to reduce the temperatures of the exhaust-valve seats, but did not have an effect on the valve-guide temperatures. The auxiliary-cooling ducts reduced temperatures of the exhaust-valve seats and rear spark plug gaskets.

Report presenting a lateral-control investigation in the 19-foot pressure tunnel of an unswept wing with 6-percent-thick hexagonal airfoil sections, aspect ratio 4.0, and taper ratio 0.625. The wing was mounted on a circular fuselage with a fineness ratio of 10 to 1.

Empirical design curves are presented for the critical stress of thin-wall cylinders loaded in axial compression. These curves are plotted in terms of the nondimensional parameters of small-deflection theory and are compared with theoretical curves derived for the buckling of cylinders with simply supported and clamped edges. An empirical equation is given for the buckling of cylinders having a length-radius ratio greater than about 0.75.

"This paper develops a new method for determining the buckling stresses of cylindrical shells under various loading conditions. In part I, the equation for the equilibrium of cylindrical shells introduced by Donnell in NACA report no. 479 to find the critical stresses of cylinders in torsion is applied to find critical stresses for cylinders with simply supported edges under other loading conditions. In part II, a modified form of Donnell's equation for the equilibrium of thin cylindrical shells is derived which is equivalent to Donnell's equation but has certain advantages in physical interpretation and in ease of solution, particularly in the case of shells having clamped edges" (p. 285).

The following report describes work carried out to investigate whether the Hanford IB column as designed in a previous report will decontaminate the uranium adequately from plutonium, particularly if there's any slowness in either the rate of reduction or transfer of the plutonium.

Abstract: "A series of experiments was carried out to determine the precision of the spectrochemical procedure for the isotopic analysis of uranium, especially at low uranium 235 concentrations. Standards were prepared from uranium hexafluoride which had been assayed on the mass spectrometer with a 95 per cent confidence interval of 0.5 per cent of the amount present. For a determination consisting of 9 separate measurements, the best precision obtained at normal concentration on the 95 per cent confidence interval was 0.711 +/- 0.112 per cent uranium 235 (16 per cent of the amount present)."

A systematic set of thermodynamic data for most of the known compounds of plutonium is presented. From earlier data present, it is now possible to extend the tabulation of data for the compounds of plutonium to include PuF(4), PuF(5), and PuF(6).

An accidental burst of radiation occurred at the laboratory on 1 February 1951 during remote control operation of a critical experiment. There was no personnel hazard. Normal operations were resumed within 24 hr, and the active material involved in the burst returned to service within three weeks. An unforeseen brief excursion into the prompt critical region was engendered in the act of scramming the assembly at the end of a series of measurements. This report describes the effects of the burst and analyzes the probable causes in some detail.

The oxidation of uranium metal has been studied from the standpoint of the oxygen dependence of the reaction rate in an effort to establish the mechanism. The experimental data of Perkins agree with the theoretical dependence of the oxygen pressure derived this report. This agreement supports the hypothesis that the rate-controlling step in the migration of cations in the DO2 lattice, although the observed time dependence is not necessarily in agreement with this conclusion. Experimental entropies of activation are corrected for the observed pressure dependence. No firm conclusion could be reached as to whether the rate of diffusion or adsorption is rate-controlling.

From introduction: "Evaluations to determine cause of fuel rods breakage following irradiation."

Report presenting generalized solutions for the actuator disk in subsonic compressible flow and the compressible- and incompressible-flow phenomena are compared. Results regarding the ideal solutions of flow variables, effect of additional losses, and actuator disks in tandem are provided. Large differences in flow variables were observed across the actuator disk.

Report presenting a comparison of the experimental wave drags of bodies and wing-body combinations over a wide range of Mach numbers with the computed drags utilizing a 24-term Fourier series application of the supersonic area rule and results of equivalent-body tests. The equivalent-body technique was found to provide a good method for predicting the wave drag of certain wing-body combinations at and below a Mach number of 1, but becomes misleading at Mach numbers greater than 1.

Memorandum presenting an investigation to determine the influence of the boundaries of a high-speed free water jet on the planing lift of a flat plate operating on the surface of the jet. No appreciable influence of speed on the planing lift coefficient for speeds from 50 to 200 feet per second was observed. Results also indicated that the parameters determining the jet size required for a given test condition have not been defined by these brief tests.

From Summary: "The results of flight tests to determine flying qualities of a Chance Vought F4U-4 airplane are presented and discussed herein. In addition to comprehensive measurements at low altitude (about 8000 ft), tests of limited scope were made at high altitude (about 25,000 ft)."

Report presenting an extensive metallographic examination of a group of buckets overtemperatured in service. Most of the buckets showed an overaged microstructure. Results regarding the metallographic survey and stress-rupture tests are provided.

Memorandum presenting several top-inlet configurations tested on a body of revolution in the 8- by 6-foot supersonic wind tunnel at a range of angles of attack and free-stream Mach numbers. The effect on performance of the following variables were studied: throat bleed, ramp perforations, inlet approach surface, side fairings, fuselage fences, canopies, and a simulated 60 degree delta wing.

This report presents the results of full-scale tests made on a 10-foot 5-inch propeller on a geared J-5 engine and also on a similar 8-foot 11-inch propeller on a direct-drive J-5 engine. Each propeller was tested at two different pitch settings, and with a large and a small fuselage. The investigation was made in such a manner that the propeller-body interference factors were isolated, and it was found that, considering this interference only, the geared propellers had an appreciable advantage in propulsive efficiency, partially due to the larger diameter of the propellers with respect to the bodies, and partially because the geared propellers were located farther ahead of the engines and bodies.

"An investigation was conducted at the NACA Lewis laboratory to determine whether simulated porous gas-turbine blades fabricated by the Eaton Manufacturing Company of Cleveland, Ohio would be satisfactory with respect to coolant flow for application in gas-turbine engines. These blades simulated porous turbine blades by forcing the cooling air onto the blade surface through a large number of chordwise openings or slits between laminations of sheet metal or wire. This type of surface has a finite number of openings, whereas a porous surface has an almost infinite number of smaller openings for the coolant flow" (p. 1).

A variable-length vacuum-insulated liquid hydrogen transfer line is described. The vacuum system is semi-permanent, and segments of the line are assembled with only threaded vacuum fittings. Thermal stress calculations are presented for a statically indeterminate union coupling.

An investigation was made of the neutron and gamma flux distribution along the entire length of a withdrawn control rod in the SRE in order to determine heating, activation and dose rates produced by the streaming neutrons and gammas.