Report issued by the Argonne National Laboratory discussing the progress and work completed between February and April, 1949. Descriptions of the studies conducted and progress made are presented. This report includes tables, illustrations, and photographs.

"High-speed wind-tunnel tests were conducted of two versions of a 0.17-scale model of the McDonnell XF2H-1 airplane to ascertain the high-speed stability and control characteristics and to study means for raising the high-speed buffet limit of the airplane, The results for the revised model, employing a thinner wing and tail than the original model, revealed a mild diving tendency from 0.75 to 0.80 Mach number, followed by a marked climbing tendency from 0.80 to 0.875 Mach number. The high-speed climbing tendency was caused principally by the pitching-moment characteristics of the wing" (p. 1).

A report which describes a number of experiments conducted to compare the effects of different methods of surface preparation on x-ray diffraction patterns of uranium obtained by the spectrometer technique.

Note presenting the method of numerical integration for calculation of beam deflection in matrix form to give it the advantages which are inherent in an influence-coefficient method. Examples are presented to show that the use of weighted matrices reduces the calculation time required to obtain a desired degree of accuracy.

Report presenting wind-tunnel tests up to a Mach number of 0.85 to determine the effects of wing-tip gun turrets on the aerodynamic characteristics of a typical bomber-wing model. Lift, drag, and pitching-moment data are presented for the wing alone; for the wing with the turrets in the clean condition; and for the wing and the turrets with guns and sighting equipment. The turrets had negligible effect on the lift and pitching-moment characteristics of the wing.

Report presenting a wind-tunnel investigation of two NACA 7-series type airfoils, one with 17.7-percent chord thickness and one with 15.4-percent chord thickness, each quipped with a 30-percent-airfoil-chord double slotted flap, a slot-lip aileron, and a trailing-edge Frise aileron with two amounts of overhang balance. Measurements of airfoil lift and drag, Frise aileron hinge moment, and slot-lip aileron hinge moment were obtained through a large range of deflection of flap, Frise aileron, and slot-lip aileron and section angle of attack. Satisfactory lateral control can be obtained by using this combination of airfoils, flaps, and ailerons.

Report discussing an Chattanooga shale adit for laboratory test samples of rock and gaining information regarding mining conditions.

This report discusses properties of the Redox process. Density, apparent molar volumes and viscosity are all described.

Report of an investigation of the effect of forebody warp on the hydrodynamic qualities of a hypothetical flying boat with a hull length-beam ratio of 15 in smooth water and in waves. Warping the forebody planing bottom was found to appreciably increase the range of stable trim between the lower and upper trim limits of stability, although the center-of-gravity limits of stability were reduced.

Report presenting an experimental investigation of a submerged air inlet incorporating a cascade of airfoils for turning and diffusing the entering air. Variables associated with submerged air inlets and airfoil-cascade designs were considered, including changes to the ramp plan form and angle for the submerged inlet and the cascade-axis inclination, cascade-blade angle, solidity, and inclination of the center line of the duct for the cascade.

Report discussing an investigation of radioactive Chattanooga black shale found in east central Tennessee.

Abstract: "The analysis of hafnium and zirconium by the copper spark technique is presented for solutions of HCl, HF, and HClO4 acids. The special techniques of electrode protection and vacuum drying of perchloric acid samples are outlined. Also given are the working curves and deviations of both elements."

Report presenting an experimental investigation of a series of exhaust mufflers installed on a typical six-cylinder light-airplane engine mounted on a ground dynamometer sound. Several conclusions regarding muffler design are drawn from this testing. Since engine and propeller noise are about equal for this power-plant installation, both engine-exhaust and propeller noises must be reduced to obtain a sizable reduction in overall sound-pressure level.

Report presenting tests to determine the recovery of total pressure attainable at a range of Mach numbers, which were performed with models with twin-scoop inlets situated on the sides of a long forebody. Results regarding ducts without slots and ducts with slots are provided.

An investigation on various can-type burners in a Bumblebee 18-inch ram jet under controlled conditions of pressure altitude and ram pressure ratio was conducted in the NACA Lewis altitude wind tunnel with kerosene as fuel. The performance of the following can-type burner configurations was better than that of the other burner configurations investigated: (1) a flame holder having a two-pitch alinement of perforations, 0.07-inch-wide cooling slots, and an arrangement of fuel nozzles located within an annulus having a mean radius of 7.24 inches; and (2) a flame holder having a zero-pitch alinement of perforations, 0.16-inch-wide cooling slots, and an annulus of fuel nozzles having a mean radius of 6.89 inches.

Memorandum presenting an investigation of the effects of stator cone angle and tip leakage on turbine performance. A single-stage turbine with 40-percent reaction was operated with two stators and two stationary shrouds. The turbine was operated at an entrance temperature of 660 degrees R with total-pressure ratios from 1.25 to 3.70 and equivalent mean blade speeds from 166 to 655 feet per second.

The present report deals with the aerodynamic, constructive, and instrumental development of a spoiler control for remote control of flying missiles.

Monthly report of the U.S. Geological Survey's trace element investigations including an outline of field work, laboratory work, and staff activities that have been completed or are in process.

"A method for calculation of a counterrotating propeller which is similar to Walchner's method for calculation of the single propeller in the free air stream is developed and compared with measurements. Several dimensions which are important for the design are given end simple formulas for the gain in efficiency derived. Finally a survey of the behavior of the propeller for various operating conditions is presented" (p. 1).

Report presenting a wind-tunnel investigation conducted in rolling flow to determine the effects of aspect ratio and sweep on the rolling stability derivatives for a series of untapered wings. The results indicated that when the aspect ratio is held constant, an increase in sweepback angle causes a significant reduction in the damping in roll at low lift coefficients for only the higher aspect ratios tested.

"In an earlier report UM No.1117 by Gothert,the single-source method was applied to the compressible flow around circles, ellipses, lunes, and around an elongated body of revolution at different Mach numbers and the results compared as far as possible with the calculations by Lamla ad Busemann. Essentially, it was found that with favorable source arrangement the single-source method is in good agreement with the calculations of the same degree of approximation by Lamla and Busemann. Near sonic velocity the number of steps must be increased considerably in order to sufficiently approximate the adiabatic curve" (p. 1).

Report presenting the partial differential equation for the perturbation velocity potential, which is examined for free-stream Mach numbers close to and equal to one. Under the assumptions of linearized theory, solutions can be found consistent with the theory for lifting-surface problems in stationary three-dimensional flow and in unsteady two-dimensional flow.

"The experimental results are presented for a part of an investigation of the compressive strength of 75S-T6 aluminum-alloy flat panels with longitudinal extruded Z-section stiffeners. This part of the investigation is concerned with panels in which the ratio of the thickness of the stiffener material to the skin material varies from 0.4 to 1.0 and the ratio of stiffener spacing to skin thickness varies from 15 to 40" (p. 1).

Note presenting a survey that has been made of the various systems of equations which have been given in the literature for the analysis of small deflections of thin elastic shell. A new system of equations has been derived for the analysis of shells, which includes the effects of transverse shear and normal stresses.