"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).

The results of tests of 22 triangular wings, representing two leading-edge shapes for each of 11 apex angles, at Mach numbers 1.62, 1.92, and 1.40 are presented and compared with theory. All wings have a common thickness ratio of 8 percent and a common maximum-thickness point at 18 percent chord. Lift, drag, and pitching moment are given for all wings at each Mach number. The relation of transition in the boundary layer, shocks on the wing surfaces, and characteristics of the pressure distributions is discussed for several wings.

"An investigation of the stability and control characteristics of a 1/10-scale model of a Canadian tailless glider has been conducted in the 10 Langley free-flight tunnel. The glider designated the N.R.L. tailless glider has a straight center section and outboard panels sweptback 43 deg. along the leading edge of the wing. The aspect ratio is 5.83 and the taper ratio is 0.323. From the results of the investigation and on the basis of comparison with higher-scale static tests of the National Research Council of Canada, it is expected that the longitudinal stability of the airplane will be satisfactory with flap up but unsatisfactory near the stall with flap down" (p. 1).

Report presenting a low-speed investigation in the stability tunnel to determine the effects of changes in profile and aspect ratio on the low-speed static-stability and rolling characteristics of triangular wings. The investigation was expanded to determine the effects of adding fins to the upper surface and of cutting portions from the tips of a triangular wing to form low-aspect-ratio tapered wings.

Report presenting the planing characteristics, as determined by tank tests, of three surfaces representative of hydro-ski forms. One surface had a rectangular plan form with a flat bottom, one had a rectangular plan form with a transversely curved bottom, and the third had a flat bottom and triangular plan form. Results are provided in the form of plots of the load on the water, resistance, trimming moment, and draft against total wetted area with speed and trim as parameters.

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 an investigation to determine the hydrodynamic characteristics of two aerodynamically refined planing-tail hulls. One hull had an afterbody shaped like a tapered boom and the other had two afterbodies with tapered booms fairing out of engine nacelles. Results regarding take-off stability and trim, landing stability, spray, resistance, directional stability, and static transverse stability are presented.

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.

"Flight tests were conducted at the NACA Pilotless Aircraft Research Station, Wallops Island, to determine the characteristics of the Allegany Ballistics Laboratory's 6.2inch-diameter Deacon and 10-inch-scale model solid-propellant rocket motors. The tests were performed to assist in the development of these rockets which were designed for, and urgently needed to propel supersonic research models and pilotless aircraft. The tests showed that the rocket motors functioned properly under various flight- acceleration loads over a range of pre-ignition grain temperatures" (p. 1).

Wind-tunnel tests of a full-scale model of the Republic XF-91 airplane were conducted to determine the distribution of pressure over the external wing fuel tank installation and over the vee tail and ventral fin. The data were obtained for a range of angles of attack and sideslip and elerudder deflection angles; the presentation is in tabular form.

Report presenting an analytical study of four combinations of subsonic and supersonic flow in the rotor- and stator-blade passages of axial-flow compressors.

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.

This report describes the flow meter for measuring air-flow rate through special hoods that allow the decrease in flow rate.

Data are presented showing compliance of C-54D with Army and Navy lateral and directional stability and control specifications. The airplane met requirements except for the rolling effectiveness pb/2V, the aileron forces in rolling, and the rudder forces in the asymmetric power conditions which were marginal. Also, the results of special tests concerning asymmetric power, asymmetric loading, and pitch due to yaw requested by the Airplane Handling Qualities Subcommittee of the Air Transport Association are presented.

Report discussing a geological study of the mineralogy of the carnotite ores of the Colorado Plateau. The report reviews the work done during the 1948 field season and proposes work to be done during the 1949 season.

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.

In programming the sequence of events in the operational cycle of the bevatron, certain devices must be triggered at specific values of magnetic field strength in the gap. It is desirable that the time-jitter, which corresponds to field jitter, of the tirggering pulses be small. In the synchrotron this is done with peaking strips which are located in the fringing field of the gap.

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.

Report presenting an investigation of the hydrodynamic take-off and landing characteristics of a model of a hypothetical jet- and rocket-propelled high-speed airplane fitted with various designs of a single monoplane hydrofoil mounted near the center of gravity. This testing is performed to determine the feasibility of the water-based operation of high-speed airplanes. Results regarding the general hydrodynamic characteristics, development of hydrofoils, and effects of some hydrofoil parameters are provided.

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

"An analysis and calculations on the stability of the free laminar boundary layer between parallel streams were made for an incompressible fluid using the Tollmien-Schlichting theory of small disturbances. Because the boundary conditions are at infinity, two solutions of the Orr-Sommerfeld stability equations need not be considered, and the remaining two solutions are exponential in character at the infinite boundaries. The calculations show that the flow is unstable except for very low Reynolds numbers" (p. 571).

A German log rodmeter of the pitot static type was calibrated in Langley tank no. 1 at speeds up to 34 knots and angles of yaw from 0 deg to plus or minus 10 3/4 degrees. The dynamic head approximated the theoretical head at 0 degrees yaw but decreased as the yaw was increased. The static head was negative and in general became more negative with increasing speed and yaw. Cavitation occurred at speeds above 31 knots at 0 deg yaw and 21 knots at 10 3/4 deg yaw.

"Results are presented from tank take-off tests of a dynamic model of a hypothetical high-speed airplane fitted with NACA hydro-skis and having the transverse curvature of the lower rear portion of the fuselage broken by small longitudinal chine strips. For the configuration tested, both trim and resistance were considerably reduced by the addition of the strips from the speed at which the ski emerged to the speed at which the rear of the fuselage came clear of the water. The results indicate that fuselage shape has a large effect on the take-off characteristics for a hydro-ski configuration in which the rear of the fuselage acts as a planing surface" (p. 1).

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.