Report presenting an investigation of the two-dimensional aerodynamic characteristics of 15 NACA airfoils at four Reynolds numbers. The results indicate that the drag coefficient at the design lift coefficient and the maximum lift coefficient are the most important aerodynamic characteristics and are most affected by Reynolds number changes.

From Introduction: "This paper presents the results of the investigation of the wing-alone and of the wing-fuselage configuration employing a wing with an unswept quarter-chord line, aspect ratio 4, taper ratio 0.6, and an NACA 65A006 airfoil section parallel to the air stream. The results of closely related sweptback-wing investigations, which are part of the present transonic programs, are presented in references 1 to 3."

Report discussing tests of a scale model of the XB-51 airplane to determine its force, stability, and control characteristics in pitch and yaw at various Mach numbers. The effects of the dive breaks and the bomb bay are also described.

Report presenting an investigation to determine the effects of a vertical tail with the leading edge swept back 63 degrees on the aerodynamic characteristics of a wing-fuselage combination with a wing with the leading edge swept back 63 degrees. The aerodynamic characteristics in sideslip with and without the vertical tail are also presented. Results regarding the directional stability, rudder effectiveness, and rudder hinge moments are described.

None

Report presenting an altitude-chamber investigation to determine the altitude performance characteristics of the British Rolls-Royce Nene II turbojet engine with an 18.41-inch-diameter jet nozzles. Testing occurred at a range of simulated altitudes and ram-pressure ratios. Results regarding the simulated flight performance, generalized performance, and effect of jet-nozzle area on performance are provided.

Report presenting airspeed and altitude data for nonscheduled cargo operations of a Douglas DC-4 airplane between Seattle, Washington and Alaska during February and March of 1947 to determine the probability of reaching or exceeding given values of airspeed and Mach number. The total probability of exceeding a placard never-exceed speed of 266 mph depends primarily on exceeding the speed in descent. The probability was found to be about once in 100 hours of descent or once in 1000 hours of general flying time.

None

None

"A study is made herein of the irrotational adiabatic motion of a gas in the transition from subsonic to supersonic velocities. A shape of the de Laval nozzle is given, which transforms a homogeneous plane-parallel flow at large subsonic velocity into a supersonic flow without any shockwaves beyond the transition line from the subsonic to the supersonic regions of flow. The method of solution is based on integration near the transition line of the gas equations of motion in the form investigated by S. A. Christianovich" (p. 1).

Report presenting an investigation to determine the lift, drag, and pitching-moment characteristics of the NACA 0010 and 0010-64 airfoil sections at Mach numbers up to 0.91 and for a range of Reynolds numbers.

Report presenting a wind-tunnel investigation of a semispan pointed wing of aspect ratio 1.7 with 60 degree leading-edge sweepback and 30 degree trailing-edge sweepforward with a control surface. The purpose of the investigation was to determine the effectiveness of flap-type controls at transonic and supersonic speeds. Results regarding the wing characteristics and control-surface characteristics are provided.

Report presenting a wind-tunnel investigation of a semispan delta wing with the leading-edge swept back 60 degrees. A half-delta control surface was used and testing was performed with and without fences. Results regarding the rolling effectiveness, wing characteristics, and control-surface characteristics are provided.

"A theoretical solution is given for the critical shear stress of a simply supported curved rectangular plate stiffened by a central stiffener offering no torsional restraint which lies in either the axial or circumferential direction. Results are obtained by means of the Galerkin method and are presented in the form of computed curves and tables" (p. 1).

None

The following report describes the developmental process of the determination of free nitric acid in solutions containing uranyl nitrate, aluminum nitrate and sodium dichromate.

Abstract: "A number of direct current conduction type electromagnetic pumps for liquid metals were constructed. Pumping capacities of over 400 gpm and efficiencies of over 50 percent were obtained. NaK alloy at temperatures up to 400 C was used in the test. The large currents required were obtained from rectifiers or from a homopolar generator constructed for the purpose."

"An additional series of high-speed wind-tunnel tests of a modified 0.17-scale model of the McDonnell XF2H-1 airplane was conducted to evaluate the effects of a reduction in the thickness-to-chord ratios of the tail planes, the displacement of the horizontal tail relative to the vertical tail, and the extension of the trailing edge of the wing. Two tail-intersection fairings designed to improve the flow at the tail were also tested. The pitching-moment characteristics of the model were improved slightly by the use of the thinner tail sections" (p. 1).

Note presenting the compressive buckling stress of outstanding flanges reinforced by bulbs, which was computed by the strain-energy method for flanges with 10 shapes and a range of lengths. The results were checked for some cases by computations based on a differential-equation method. The results were analyzed to determine which shape of flange gave the greatest support to the structure to which it was attached.

Memorandum presenting an analysis of selected experimental pressure-distribution data at transonic speeds for the purpose of deriving an empirical method which may be used for estimating the trailing-edge loads and bending moments at the design stage. The trailing-edge normal-force and bending-moment coefficients calculated by the derived method follow the general trend of the experimental data and appear to be a guide where specifically applicable chordwise pressure-distribution data at transonic speeds are not available.

Report presenting an experimental study of the pressure fluctuations at the combustion-chamber inlets of a ramjet operating a Mach number of 1.92 in the supersonic tunnel. Results are presented for two burner configurations of different operating characteristics to indicate trends in pressure magnitude, frequency, and wave form. Results regarding the perforated conical flame holder, regenerative-type burner, and diffuser total-pressure recovery are provided.

From abstract: "The present report describes experimental work performed to establish a procedure for the production of uranium metal wire. In all cases, the size of the initial rod was 1/2 inch diameter. Three materials were used: hot extruded tuballoy rod, high purity cast tuballoy rod, and cast U-235 rod."

None

Report presenting rocket-powered flight tests from high subsonic to supersonic speeds and at high Reynolds numbers to determine the zero-lift drag of a transonic wing-body and body-alone configuration. The configuration tested featured a wing of 45 degree sweepback, aspect ratio 4, taper ratio 0.6, and an NACA 65A006 airfoil section, and a body of fineness ratio of 10 and a frontal area equal to 6.06 percent of the wing-plan-form area.