Note presenting an investigation of three centrifugal impellers, the same except for angular blade curvature, to determine the effect of the distribution of blade loading on impeller performance. Results regarding impeller efficiency, energy addition and pressure ratio, flow characteristics, and operating range are provided.

Report presenting the results of testing in the transonic range of four flutter airfoils attached to a freely falling body. Failures of the airfoils were metered and recorded in order to determine the Mach numbers and altitudes of failure.

"A solution based upon small-deflection theory is presented for the critical shear stress of curved rectangular panels with simply supported edges. Computed curves which cover a wide range of panel dimensions are presented; these curves are found to be in good agreement with test results. Estimated curves are also given for panels with clamped edges" (p. 1).

Report presenting the aerodynamic characteristics of 19 isolated tail surfaces, which have been determined by wind tunnel tests. Testing was also made of rectangular airfoils of various aspect ratios with and without double end plates of various shapes. The analysis indicated that the slope of the lift curve could be predicted within 10 percent for all models by use of lifting-surface-theory equations.

Abstract: The procedures recommended for analysis in Department 190 Laboratories, in the Limits Control Laboratory, and in the Analytical Development Laboratories, of all process materials from the HCP cycle are presented in a stepwise manner. A description of the characteristics of each sample type along with a brief description of factors involved in the Analytical Quality Control program is included.

Report presenting tests to determine the damping in roll and aileron rolling effectiveness of three wings with different degrees of sweepback. The results showed that the values of damping in roll decreased with increasing sweepback. The rolling effectiveness of the aileron of the sweptback wing was found to be predicted with fair accuracy from static aileron-rolling-moment tests and wing-damping tests.

Powered models of three different flying boats were landed in oncoming wave of various heights and lengths. The resulting motions and acceleration were recorded to survey the effects of varying the trim at landing, the deceleration after landing, and the size of the waves. One of the models had an unusually long afterbody. The data for landing with normal rates of deceleration indicated that the most severe motions and accelerations were likely to occur at some period of the landing run subsequent to the initial impact.

In accordance with a request of the Bureau of Aeronautics, Navy Department, tests were performed in the Langley 20-foot free-spinning tunnel to determine the spin and recovery characteristics of a 1/24 scale model of the Grumman XTB3F-1 airplane. The airplane is a two-place, midwing torpedo bomber equipped with a tractor propeller and an auxiliary jet engine. The effect of control setting and movement on the erect and inverted spin and recovery characteristics of the model were determined for the normal loading.

"The spin and recovery characteristics of the Curtiss-Wright XP-87 airplane, as well as the spin-recovery parachute requirements, the control forces that would be encountered in the spin, and the best method for the crew to attempt an emergency escape, are presented in this report. The characteristics were estimated rather than determined by model tests because the XP-87 dimensional and mass characteristics were considered to be noncritical and because data were available from model tests of several similar airplanes. The study indicated that the recovery characteristics of the airplane will be satisfactory for all loadings if the controls are reversed fully and rapidly" (p. 1).

Report presenting a test-stand investigation conducted on a rectangular ramjet engine design for installation in an aircraft wing. The engine operated without excessive engine noise or vibration over the entire range of operating conditions. Results regarding inlet velocity, exhaust flame characteristics, fuel-air ratio, and total-temperature rise are provided.

Note presenting a determination of friction coefficients for three constant-area vaneless diffusers, used in conjunction with a centrifugal impeller, from static- and total-pressure surveys taken at several radii and from the usual overall measurements of temperature, pressure, and air flow. The average value of the friction coefficient through the entire diffuser was approximately 50 percent higher than that for fully developed turbulent flow in smooth pipes.

Note presenting an investigation to determine the stability and control characteristics of an airplane model with a skewed wing in the free-flight tunnel. Flight tests, force tests, and damping-in-roll tests were made on the model with the wing set at angles of skew from 0 to 60 degrees. The investigation was of an exploratory nature and was intended to provide only a preliminary and qualitative indication of whether such a design could be flown.

Report presenting tests of an NACA 4-(5)(08)-03 two-blade propeller in the 8-foot high-speed tunnel for blade angles of 45 and 60 degrees extending the Mach number range from that of previous tests of the propeller up to Mach number 0.913. When the forward speed was increased from a low value to a forward Mach number of 0.90, the loss in peak efficiency was found to be not more than 47 percent.

This report for May, 1947 describes progress regarding analytical work, chemical work, beta-counting methods of analysis, ore-dressing and pyrometallurgical studies, and pyrometallurgical work.

Report presenting wind-tunnel testing to determine the low-speed lift, drag, and pitching-moment characteristics of a 40 degree sweptback wing with high-lift and stall-control flaps and a fuselage with a fineness ratio of 10.2 to 1. Low, medium, and high-wing-fuselage combinations were tested at high Reynolds numbers. Results regarding the high-lift and stall-control flaps and wing-fuselage combinations are provided.

Report issued by the U.S. Bureau of Mines on exploration of kaolin clay deposits for alumina. Properties of the kaolin clay and alumina recovered are listed. This report includes tables, graphs, and illustrations.

Note presenting an application of the iterative interference method to three problems concerning the design of cascades. The three problems considered include the determination of the shape and setting of thin blades with a prescribed type of vortex distribution, determination of the shape and setting of thin blades with certain prescribed types of pressure distributions, and determination of the blade setting for a cascade of given airfoil shape and solidity.

Report presenting testing of a standard turbojet engine by water injection at the inlet of the axial-flow compressor in the altitude wind tunnel. Engine performance at 7600 rpm was obtained over a wide range of water-air-pressure ratios and ram-pressure ratios. Results regarding the engine-component performance are also provided.

"At the request of the Air Material Command, Army Air Forces, an investigation was conducted by the NACA Cleveland laboratory to determine the performance characteristics of the compressor of the XJ-41-V turbojet engine. This report is the second in a series presenting the compressor performance and analysis of flow conditions in the compressor. The static-pressure variation in the direction of flow through the compressor and the location and the cause of the maximum flow restriction at an equivalent speed of 8000 rpm are presented" (p. 1).

Report presenting an investigation of the forward-flight performance characteristics of a typical single-rotor helicopter equipped with main and tail rotors. Testing occurred over a range of tip-speed ratios and thrust coefficients. Results regarding the fuselage effects and rotor characteristics are provided.

"An experimental investigation of the general instability of reinforced thin-walled metal cylinders was carried out at the California Institute of Technology. The basic parameters involved were the spacing and sectional properties of the stiffening elements, the wall thickness, and the diameter of the cylinder. An analysis of the experimental data led to a suitable parameter for estimating the general instability stress of reinforced metal cylinders when subjected to pure torsion loading" (p. 1).

Report presenting a determination of the tunnel-induced velocities for yawed and swept-back airfoils in a closed circular wind tunnel. Calculations were performed for elemental horseshoe vortices with one tip of the bound vortex on the tunnel axis for a range of yaw angles and bound-vortex lengths.

Report presenting an investigation of two 10-foot-diameter three-blade propellers to determine the effect of swept-back blade tips on propeller aerodynamic characteristics. Results regarding the effect of swept-back tips on maximum efficiency and constant-power propeller operation are provided.

Introduction. The main objective of the Metallurgical Project was the preparation of large quantities of plutonium 239, an isotope of element 94, by the interaction of neutrons and uranium. At the beginning, only predictions of its chemical and biological properties could be made since it is a new element. It was predicted that it would be toxic to tissue by virtue of its high atomic weight, and in addition, that it would be toxic by virtue of its radioactivity. Thus, the preparation and use of the element on a large scale meant the manipulation of, and possible exposure to, toxic quantities. It was, therefore, of practical importance to obtain data which would elaborate on the predicted toxicity. The objectives of the work reported here were to establish the acute toxicity of plutonium in experimental animals and to study the distribution of the element in the body after the administration of a wide range of doses. In the interest of economy of what was, at that time, a rare substance, and of animals and facilities, these two objectives were frequently pursued in the same experiment. The information obtained from the separate experiments is therefore frequently incomplete in one or another respect. …