Report presenting drag coefficients determined by the accelerometer method for the Bell X-1 airplane with 8-percent-thick wing and 6-percent-thick tail in power-off flight over a range of Mach numbers and lift coefficients. Results regarding the variation of computed lift and drag coefficients, variation of lift coefficient with Mach number, and effect of Mach number on lift-drag ratio are provided.

Report presenting results and analysis of the longitudinal stability and control characteristics of the Douglas D-558-I airplane at a range of altitudes and Mach numbers. It was found that large and rapid changes in elevator deflection and force were required for balance at Mach numbers above 0.84 due to a sharp decrease in elevator-stabilizer effectiveness.

Report presenting an investigation of some effects of aileron spanwise location and wing structural rigidity on the rolling power of 0.3-chord plain, flap-type ailerons on a wing with a taper ratio of 0.25, an aspect ratio of 3.5, and swept back 63 degrees at the leading edge. Results regarding the aeroelastic effects and aileron span and spanwise location are provided.

Memorandum presenting an NACA submerged inlet and an NACA series I nose inlet installed in bodies of 12.4 fineness ratio to determine the drag and pressure-recovery characteristics of each body-inlet configuration. The tests were conducted with large-scale free-fall models released at an altitude of 40,000 feet, for mass-flow ratios of about 0.4 and 0.7 over a Mach number range of about 0.70 to 1.10. Results regarding drag and ram-recovery ratios are provided.

"A simple apparatus particularly applicable to the determination of the corrosive effects of flowing liquid metals on structural materials is described. In this apparatus, flow of the liquid medium at known velocities may be induced in toroidal shaped channels fabricated from the test structural material only, with no pump, valves, or flow meter required. A circulating velocity of 25 ft/sec has been obtained in preliminary tests and no basic limitation on increasing the speed was encountered" (p. 1).

Memorandum presenting a study of the effect of prestrain in tension upon the stress-strain characteristics in compression for copper and brass. The residual stress phenomenon known as the Bauschinger effect is of primary importance in cyclic loading, inasmuch as it serves to reduce the yield strength of plastically strained metal to deformation of the opposite sign.

Report discussing an investigation of the effect of sweepback angle on wing-fuselage characteristics at a subsonic and a supersonic Mach number. Lift, drag, and pitching-moment coefficients, downwash-angle, and total-pressure measurements are all provided.

This report presents the results of an investigation to ascertain the lift, drag, and pitching moment of a wing-body combination having a triangular wing of aspect ratio 2 with NACA 0003-63 thickness distribution in streamwise planes and twisted and cambered for a nearly elliptical span load distribution. Results are shown for Mach numbers from 0.60 to 0.90 and from 1.30 to 1.70 at Reynolds numbers of 3.0 million and 7.5 million.

Report presenting design features for the instrumentation used in a study of the transient performance of gas-turbine engines and control systems. The dynamic characteristics of the instrumentation are discussed and examples of typical acceleration data for a controlled and an uncontrolled engine are provided.

Memorandum presenting low-speed tests of a semispan tapered wing with the leading edge swept back 63 degrees and with the NACA 0010 section cambered for a lift coefficient of 1.0 perpendicular to the leading edge to determine the extent to which stability characteristics could be improved by cambering the wing.

Report presenting measurements of pressure made over the chord of a swept-wing model at four stations along the span by the NACA wing-flow method. The model was an untapered 45 degree sweptback wing of aspect ratio 3.5 with 2-inch-chord NACA 65-210 airfoil sections normal to the leading edge. Results regarding the chordwise pressure distributions and spanwise distributions of section lift, drag, and pitching moment.

Report presenting the results of pressure-distribution and force tests on four wings at Mach number 6.86 and Reynolds number 980,000 in the 11-inch hypersonic tunnel. Characteristics of the wings tested included a 4-inch square plan form, a 5-percent maximum thickness, and diamond, half-diamond, wedge, and half-circular-arc sections. Information about pressure measurements, wing characteristics, and Schlieren photographs is provided.

Report presenting pressure distributions and wake measurements for wings with 30 and 45 degrees of sweepforward, in conjunction with a midwing fuselage, at Mach numbers up to 0.96. The wings had an NACA 65-210 section, a taper ratio of 0.38, and aspect ratios of 7.5 and 5.2. Results regarding pressure distributions, wake measurements, and corrections are provided.

Effect of three surface finishes of roughness 4 to 5, 20 to 25, and 70 to 80 micro inches rms on fatigue properties were determined for low-carbon N-155 alloy of grain size A.S.T.M. 1 at temperatures of 80 , 1000, 1350, and 1500 F. The fatigue properties for the various finishes differed appreciably at room temperature; however, after short periods at 1000 F and for all periods investigated at temperatures above 1000 F, the specimen finishes had the same fatigue strength. It was concluded that the primary cause of the difference in room-temperature strength was due to compressive stresses set up in the surface and that at elevated temperatures these compressive stresses were relieved by annealing.

Report presenting testing of a series of three wings over a range of Mach numbers by the use of the transonic-bump technique. The lift, drag, pitching-moment, and root-bending-moment data of wings of a variety of aspect ratios but with the same quarter-chord lines and airfoil sections were obtained.

"Tabulated pressure coefficients and aerodynamic characteristics are presented for six spanwise stations on the left wing of the Bell X-1 research airplane. The data were obtained in an unaccelerated stall and in pull-ups at Mach numbers of 0.74, 0.75, 0.94, and 0.97" (p. 1).

Report presenting some highlights of recent experimental studies of flutter at high speeds. Flutter problems have become more varied with the advent of transonic flight and importance of aeroelasticity, and the flutter field has merged with other aspect of aeroelasticity such as divergence and buffeting. The two main subjects of flutter, classical flutter and stall flutter, are explored in these studies.

"A camera designed for use in flight has been developed by the NACA Lewis laboratory to photograph cloud droplets in their natural suspension in the atmosphere. A magnification of 32 times is employed to distinguish for measurement purposes all sizes of droplets greater than 5 microns in diameter. Photographs can be taken at flight speeds up to 150 miles per hour at 5-second intervals, A field area of 0.025 square inch is photographed on 7-inch-width roll film accommodating 40 exposures on an 18-foot length" (p. 1).

Report presenting pressure distributions, wake measurements, and tuft patterns for wings with 30 and 45 degrees of sweepback in conjunction with a midwing fuselage at Mach numbers to 0.96. The wings have an NACA 65-210 section, a taper ratio of 2.6:1, and aspect ratios of 7.5 and 5.2. The study indicated that when the Mach number reached high subsonic values at low angles of attack, the locations of peak negative pressure coefficients on the upper surfaces of the sections near the wing-fuselage junctures shifted rearward.

Report presenting an investigation in the 19-foot pressure tunnel to determine the effects of a fuselage and a horizontal tail located at various vertical positions on the low-speed longitudinal characteristics of a circular-arc 52 degree sweptback wing. Results regarding the effect of fuselage on longitudinal characteristics of the wing, effect of tail position on stability and tail effectiveness, and air-flow characteristics are provided.

Memorandum presenting an investigation to evaluate the effect of Reynolds number and Mach number on the aerodynamic characteristics of a horizontal tail of aspect ratio 3 equipped with a plain, sealed, full-span elevator. The line joining the quarter-chord points of the airfoil sections was swept back 45 degrees and the sections perpendicular to this line were the NACA 64A010. Results regarding the effect of Reynolds number and effects of leading-edge roughness and elevator-nose seal are provided.

Report presenting a study of the flow phenomena within the rotating passages of a 48-inch radial-inlet impeller at low tip speeds. Total and static pressures were measured within the impeller passages at two different tip speeds by using a suitable pressure-transfer device to transmit the pressures from the rotating passages to the stationary measuring station. Results regarding the overall compressor performance, static-pressure distribution along blades, total-pressure distribution across the passage, static-pressure distribution across the passage, pressure distribution from hub to shroud, and power input to impeller are provided.

The paper presents flight measurements of the dynamic lateral stability of the D-558-II (BuAero No. 37974) research airplane. Data are presented for a range of calibrated airspeed from 167 miles per hour to 474 miles per hour.

Memorandum presenting the pressure recovery, mass flow, and axial force of four bodies with nose inlets measured at Mach numbers between 1.4 and 2.0 and angles of attack of 0, 3, 6, and 9 degrees. The drag coefficients of axially symmetric diffusers operating at the maximum mass-flow rates were calculated from schileren photographs of the head shock waves and frictional drag considerations. Results regarding open-nose diffusers and conical-shock diffusers are provided.