From Introduction: "Tests have recently been conducted in the Langley 8-foot high-speed tunnel (reference 1) to study the effects of changes in operating advance ratio, blade plan form, blade-section thickness, section camber, and other variables on the on the propeller characteristics in the transonic-speed range. The method in reference 2, which evaluated the profile drag losses and the induced losses seperately, is followed in this paper. The method as presented offers the general prediction of propeller performance, and can be used to supplement the experimental data."

Report presenting a blade-vibration survey that was conducted during normal operation of a 10-stage axial-flow compressor powered by part of a complete jet engine. Strain-gage records were obtained from all stages during acceleration, deceleration, and constant-speed runs. Results regarding the inlet disturbances and damping characteristics are provided.

Report on the atomic bomb injuries in Hiroshima City.

Report presenting an investigation of the time lag between flap deflection and force development on a rectangular wing with a 9-percent-thick symmetrical circular-arc profile with a full-span 30-percent-chord flap. This was performed in order to determine further information about the rapidity of response for a supersonic missile after a given flap deflection due to the potential time lag between the deflection of the controls surfaces and the development of aerodynamic forces.

Memorandum presenting pressure-distribution and force data at various angles of attack of a triangular wing of aspect ratio 2 and having an NACA 0005 modified section. The wing had a plain, constant-chord, trailing-edge flap which was deflected 0 and 10 degrees. Results regarding the gross force characteristics of the wing, including lift, drag, pitching-moment, and flap hinge-moment coefficients are provided.

Report discussing the progress made on the Experimental Breeder Project during the period from March 1, 1949 to January 31, 1950.

Report discussing a procedure for the preparation of anhydrous vanadium trifluoride. From abstract: "By selecting proper operating conditions and equipment, a method of preparation was devised such that anhydrous vanadium trifluoride of high purity was produced reliably in five pound batches." The method of preparation involves manipulating the starting material, vanadium pentoxide.

Report presenting an investigation of thrust augmentation by injection of water and water-alcohol mixtures in the combustion chambers at sea-level zero-ram flight conditions on 4000-pound-thrust axial-flow and centrifugal-flow turbojet engines. Thrust augmentation, compressor characteristics, fuel flow, and turbine-outlet-temperature distributions are presented for various injection rates and water-alcohol mixtures.

A method is presented for analysis of the compressible flow between the hub and the shroud of mixed-flow impellers of arbitrary design. Axial symmetry was assumed, but the forces in the meridional (hub to shroud) plane, which are derived from tangential pressure gradients, were taken into account. The method was applied to an experimental mixed-flow impeller. The analysis of the flow in the meridional plane of the impeller showed that the rotational forces, the blade curvature, and the hub-shroud profile can introduce severe velocity gradients along the hub and the shroud surfaces. Choked flow at the impeller inlet as determined by the analysis was verified by experimental results.

Report presenting additional wind-tunnel tests of a model of the X-3 airplane at low and high subsonic numbers to investigate the lateral and longitudinal-stability and control characteristics. Results regarding the aerodynamic characteristics in pitch and aerodynamic characteristics in yaw are provided.

From abstract: This paper presents temperature-entropy and Mollier charts for sodium, and describes briefly the method used for their construction, based upon data from the literature.

Report presenting results obtained with quiescent fuel-air mixtures and with small diffusion flames, which indicate that combustion efficiencies close to 100 percent were obtained at pressure much lower than those found in turbojet combustors at altitudes of 60,000 feet.

To determine effect of nonuniform inlet-air velocities, a full scale, axial-flow turbojet engine was investigated in Lewis altitude wind tunnel at altitudes from 20,000 to 50,000 feet, 0.21 flight Mach number and corrected engine speeds from 77.3 percent of rated speed to rated speed. Total-pressure variations as large as 103 pounds per square foot in radial direction and 90 pounds per square foot in circumferential direction at 30,000 feet were obtained. With the distortions investigated, net thrust varied between 0.95 and 1.03 of the thrust with uniform inlet-air distribution. Similarly the ratio of specific fuel consumption varied from 1.00 to 1.04. Within the arrange of this investigation the effects of nonuniform inlet velocity were not serious for the engine investigated.

Report presenting the use of porous-walled tunnels at supersonic Mach numbers as a means of avoiding reflection of a stream disturbance extending to the walls. Results from analysis and an experiment with a 4 degree wedge at a Mach number of 1.2 are provided.

The tests described in this report were static tests devised to afford a basis for a quick evaluation of the resistance of uranium to attack by lithium. The work was done at the same time as the tests of beryllium, thorium, and various engineering metals in lithium (described in ANL-4990); but the results with uranium are given in the present classified report so that the results of the other tests can be published as an unclassified document. The procedure for carrying out the tests is described in ANL-4990.

Ignition characteristics of AN-F-32 and two AN-F-58a fuels were studied in a single can-type turbojet combustor under air-flow conditions representing engine speeds of 1600, 2500, and 4000 rpm, altitudes from sea level to 30,000 feet, ambient temperatures at sea level from 90 degrees to minus 36 degrees F, and flight Mach numbers of 0 and 0.6. Critical fuel-flow rates for ignition increased with increase in preignition engine speed, with increase in altitude, or with decrease in sea-level ambient temperature. This flow rate appears to increase in a direct relation to decrease in fuel volatility as indicated by the 10-percent-evaporated temperature.

A preliminary study was made of the feasibility of three cycles for nuclear propulsion of aircraft: a direct-air-turbojet, a binary liquid-metal turbojet, and a helium compressor jet. All three cycles appeared feasible for flight at a Mach number of 0.9 and altitudes up to 50,000 feet; the liquid-metal cycle appeared feasible for flight at a Mach number of 1.5. The air and helium cycles resulted in heavier aircraft than did the liquid-metal cycle, particularly at a Mach number of 1.5. The relative advantage of the liquid-metal cycle became greater as the flight speed and altitude increased, and as the reactor wall temperature decreased.

Report discussing an investigation into the ability of human pilots to control short-period yawing oscillations using a yaw simulating device. The ability to control the oscillations was determined to be a function of period, control effectiveness, and inherent damping. Pilot control effectiveness was found to improve with practice.

"This report briefly summarizes some of the available information on fuels for gas-turbine powered aircraft. The effects of fuel volatility and composition on the range, reliability, and safety of aircraft are discussed. Availability is briefly considered for fuels at various volatility levels" (p. 1).

Report presenting an investigation in the free-flight tunnel to study the dynamic longitudinal stability of equal-size models coupled in tandem with a single joint providing freedom in pitch. Results regarding the characteristics of the model motions, effect of elevator gearing ratio, effect of weight ratio, and effect of static stability of the front model are provided.

A method is presented which allows the use of nonlinear section lift data in the calculation of the spanwise lift distribution of unswept wings with flaps or ailerons. This method is based upon lifting line theory and is an extension to the method described in NACA rep. 865. The mathematical treatment of the discontinuity in absolute angle of attack at the end of the flap or aileron involves the use of a correction factor which accounts for the inability of a limited trigonometric series to represent adequately the spanwise lift distribution. A treatment of the apparent discontinuity in maximum section lift coefficient is also described. Simplified computing forms containing detailed examples are given for both symmetrical and asymmetrical lift distributions. A few comparisons of calculated characteristics with those obtained experimentally are also presented.

Technical report describing results on work which cannot be ascribed to one reactor program. Outlines the results of miscellaneous corrosion testing, the development of new shielding materials, the testing of irradiated plastics, and general heat transfer investigation. [From Preface]

"A summary of methods for making dynamic lateral stability and response calculations and for estimating the aerodynamic stability derivatives required for use in these calculations is presented. The processes of performing calculations of the time histories of lateral motions, of the period and damping of these motions, and of the lateral stability boundaries are presented as a series of simple straightforward steps. Existing methods for estimating the stability derivatives are summarized and, in some cases, simple new empirical formulas are presented. Detailed estimation methods are presented for low-subsonic-speed conditions but only a brief discussion and a list of references are given for transonic and supersonic speed conditions" (p. 1).

Report presenting results during demonstration flight tests of the Northrop X-4 No. 1 and No. 2 airplanes. Results regarding the static and dynamic longitudinal- and lateral-stability characteristics, the stalling characteristics, and the buffet boundary.