Report presenting a preliminary investigation of cone-type diffusers designed for minimum spillage at the inlet during operation in the supersonic tunnel at Mach number 1.85. Pressure recoveries of a series of stationary cones with included angles from 20 degrees to 60 degrees were investigated. Results regarding the pressure recovery with stationary cones and pressure recovery of movable-cone configurations are provided.

This report contains a selected list of Government sponsored research projects on related aircraft materials in effect during the calendar year 1947. Information is contained on titles, description, sponsoring and conducting agencies.

Report presenting an investigation to study cowling-spinner combinations based on the NACA 1-series nose inlets and to obtain systemic data for one family of approximately ellipsoidal spinners. 11 of the spinners were also tested in various combinations with 9 NACA open-nose cowlings, which were also tested without spinners. Results regarding flow over spinners, internal flow, external flow over cowling, critical Mach number characteristics, envelope values, and cowling section are provided.

Report presenting testing of six flutter wings, two swept 45 degrees and four unswept, attached to three freely falling bodies. Flutter frequency and phasing were recorded.

Testing was conducting to evaluate the effects of support interference on the drag characteristics of two bodies of revolution at zero angle of attack at Mach number 1.5. Drag and base-pressure measurements are made for a variety of Reynolds numbers to determine the effect of varying the length or diameter of the rear support.

"It is shown how Schrenk's empirical method of estimating the lift distribution over straight wings can be adapted to swept wings by replacing the elliptical distribution by a new "ideal" distribution which varies with sweep.The application of the method is discussed in detail and several comparisons are made to show the agreement of the proposed method with more rigorous ones. It is shown how first-order compressibility corrections applicable to subcritical speeds may be included in this method" (p. 1).

Report presenting measurements of downwash angles at points at two vertical positions at the probable tail location behind a high-aspect-ratio wing with an NACA 65-210 section with no sweep and 30 degrees and 45 degrees of sweepback and sweepforward in conjunction with a fuselage.

Report presenting the results of testing on a model of the D-558-1 in order to determine its pitching-moment, lift, and drag characteristics with no nose-inlet flow, and with the tail removed and at a constant setting. Only a limited analysis is provided.

The effects on dynamic lateral stability and controllability of some of the important aerodynamic and mass characteristics are discussed and methods are presented for estimating the various stability parameters to be used in the calculation of the dynamic lateral stability of airplanes with swept and low-aspect-ratio wings.

Report presenting an experimental investigation at zero flight speed and sea-level conditions on a 4000-pound-thrust centrifugal-flow-type turbojet engine to determine the amount of thrust augmentation obtainable at maximum rotor speed by the injection of water, alcohol, and water-alcohol mixtures at the compressor inlets. A maximum thrust augmentation of 26 percent was obtained by the injection of 4.5 pounds per second of water and 2.0 pounds per second of alcohol. Results regarding the tail-pipe gas temperature, air-flow and compressor-outlet pressure, fuel flow, specific liquid consumption, and thrust augmentation are provided.

Report presenting an investigation of the rolling effectiveness of a wing-spoiler arrangement using a rocket-propelled test vehicle in free flight. The configuration investigated in the report is likely not optimum and indicates a need for further exploration.

"A spin investigation has been conducted in the Langley 20-foot free-spinning tunnel on a 1/24-scale model of the North American XP-86 airplane. The effects of control settings and movements upon the erect and inverted spin and recovery characteristics of the model were determined for the design gross weight loading. The long-range loading was also investigated and the effects of extending slats and dive flaps were determined" (p. 1).

Memorandum presenting an investigation of an axial-flow compressor rotor operating with supersonic velocities relative to the blade rows in order to determine the performance characteristics in air and to confirm the performance obtained in Freon-12 at another laboratory. Results regarding the weight flow, work of compression, pressure ratio and adiabatic efficiency, and entry of shock are provided.

Report presenting testing on a series of five flat plate models of aspect ratio 2.0 with 25-percent-mean-aerodynamic-chord flaps at a range of Mach numbers in order to investigate the effect of sweepback on flap effectiveness.

Report presenting calculations to determine the effect of several operating conditions on the performance of condensers for steam-turbine power plants. The analysis covered a range of turbine-inlet pressures and turbine-outlet pressures for various condenser cooling-air pressure drops, flight speeds, and altitudes. Results regarding steam-cycle performance, effect of turbine-outlet pressure on condenser performance, effect of cooling-air pressure drop on condenser performance, effect of turbine-inlet temperature on condenser performance, and power-plant-weight estimates are provided.

Memorandum presenting a review of information relating to aircraft fires to determine what new or further research might lead to a substantial reduction of the aircraft fire hazard in flight and following crashes. An examination of fuels, lubricants, and hydraulic fluids as inflammable liquids is presented, together with possible sources of ignition under the general categories of hot surfaces, electric sparks and arcs, flames, and hot gases.

The problems of static and dynamic longitudinal stability both at high speeds and at low speeds are discussed and data are presented which indicate recent progress made in the solution of these problems.

Report presenting an investigation of the problems of static and dynamic longitudinal stability both at high speeds and low speeds as well as information about progress that has been made to solve these problems. The incorporation of large amounts of sweepback on both the wing and horizontal tail can improve the rate of trim changes and stability. Longitudinal stability has been attained for configurations with a sweep angle of 45 degrees with stall-control devices, but experimental proof is needed for these devices.

Report presenting an investigation of the properties of hydrazine, stability and corrosiveness with a number of construction materials, sensitivity to detonation and temperature, and spontaneous reaction with the oxidants, concentrated hydrogen peroxide, sodium permanganate solution, fuming nitric acid, and tetranitromethane. Results regarding corrosion and stability, sensitivity to temperature and detonation, and theoretical calculations are provided.

An investigation is being conducted to determine the altitude performance characteristics of the British Nene II engine and its components. The present paper presents the preliminary results obtained using a standard jet nozzle. The test results presented are for conditions simulating altitudes from sea level to 60,000 feet and ram pressure ratios from 1.0 to 2.3. These ram pressure ratios correspond to flight Mach numbers between zero and 1.16 assuming a 100 percent ram recovery.

"This report presents the results of pilot observations and photographs of the compression shock wave on the wing of an airplane in flight. A detailed description of the test conditions necessary and the procedure to be following in producing the visible shock are presented. The pilot's observations of the occurrence of an oscillating shock wave and its possible relationship with the airplane buffeting are also presented" (p. 1).

Report presenting testing of a 42.7 degree sweptback tapered wing with three types of ailerons tested at a Mach number of 1.9 and a Reynolds number of 2,200,000; the wing geometry was similar to that of an XS-2 airplane. The purpose of the investigation was to determine the effectiveness of ailerons at these specified flight characteristics. Results regarding the aerodynamic characteristics of the wing are also provided.

Report presenting testing in the 300 mph tunnel of a model with a sweptback vee tail and a sweptback wing to determine its low-speed stability and control characteristics. The results are compared to testing with the same tail panel with zero dihedral on the same wing-fuselage combination. The longitudinal stability characteristics, downwash at the tail, longitudinal control characteristics, lateral stability characteristics, and rudder control characteristics are provided.

From Summary: "Theoretical performance data including nozzle-exit temperature, specific impulse, volume specific impulse and composition, temperature, and mean molecular weight of reaction products based on frozen equilibrium and isentropic expansion are presented for 13 propellant combinations at reaction pressure of 300 pounds per square inch absolute and expansion ratio of 20.4. On basis of maximum specific impulse alone, five fuels had the following order for any given oxidant: liquid hydrogen, hydrazine, liquid ammonia, and either hydrazine hydrate or hydroxylamine. Three oxidants with a given fuel had the following order: liquid ozone, liquid oxygen, and 100-percent hydrogen peroxide."