"As part of the performance investigation of compressors for the J33 turbojet engine, the A-21 model and the A-23 model with a 17- and a 34-blade impeller were operated with water injection at their respective design equivalent speeds of 11,500 and 11,750 rpm. Inlet conditions of pressure of 14 inches of mercury absolute and of ambient temperature correspond to those of the investigation of these models without water injection. The water-air ratio by weight ranged from 0.05 to 0.06. By the use of water injection, the peak pressure ratio of the A-21 compressor and the A-23 compressor with a 34-blade impeller increased approximately 0.38, whereas that of the A-23 compressor with a 17-blade impeller increased only 0.14" (p. 1).

Report presenting an investigation of the effect of hull length-beam ratio on the hydrodynamic characteristics of flying boats that extend to a length-beam ratio of 20. The results are compared with flying boats having a length-beam ratio of 15. Results regarding longitudinal stability, spray characteristics, take-off performance, taxiing and take-off behavior in waves, landing behavior in waves, and a summary chart are provided.

From Summary: "Measurements of wing and fuselage pressure distributions were made at low and high subsonic Much numbers on a 0.16-scale model of the projected MX-656 research airplane. The MX-656 is a supersonic design utilizing a low-aspect-ratio wing and tail. Pressure-distribution measurements indicated that, although the critical Mach number of the wing was approximately 0.81 at 0 degree angle of attack, compressibility effects were of little significance below a Mach number of at least 0.90. The principal effect of compressibility was an increase in the pressure gradient over the after 30 percent of the wing chord, causing a tendency for the flow to separate."

"In a round turbulent jet at room temperature, measurement of the shear correlation coefficient as a function of frequency (through band-pass filters) has given a rather direct verification of Kolmogoroff's local-isotropy hypothesis. One-dimensional power spectra of velocity and temperature fluctuations, measured in unheated and heated jets, respectively, have been contrasted. Under the same conditions, the two corresponding transverse correlation functions have been measured and compared" (p. 1).

From Introduction: "An analysis of eddy currents in a compressor blade, the geometry of which has been limited to that of a flat plate for simplicity, is presented."

"Available information on gust structure, airplane reactions, and pertinent operating statistics has been examined. This report attempts to coordinate this information with reference to the prediction of gust loads on airplanes. The material covered represents research up to October 1947" (p. 807).

"Abrupt rudder-fixed aileron rolls have been made with the Bell X-1 airplane in powered flight at Mach numbers between 0.90 and 1.06 at about 40,000 feet pressure altitude. These aileron rolls indicate that the aileron effectiveness for large deflections at Mach number 0.94 is only one-fourth the value at Mach number 0.82, and the effectiveness at Mach number 1.06 is slightly greater than at Mach number 0.94" (p. 1).

Report presenting the results of flight tests showing lateral oscillation in the Bell X-1 and calculations created to determine the effects of changes in several mass and aerodynamic parameters on the lateral oscillations. Calculations indicate that lateral stability should be improved by a more positive inclination of the principal axis of inertia or a reduction of the value of yawing moment of inertia.

Results of previous model ditching tests of the Lockheed Constellation airplane are reported. Further model tests have been made to determine the probable ditching characteristics and the proper ditching technique for the airplane with the Speedpak attached. This paper presents the results of these tests. Design information was furnished by the Lockheed Aircraft Corporation. A three-vies drawing of the airplane with the Speedpak attached is shown. The tests were made in calm water at the Langley tank no.2 monorail.

"An experimental investigation, using microscopic observation and color motion photomicrographs of the action, was conducted to determine the cause of fretting. Glass and other noncorrosive materials, as well as metals, were used as specimens. A very simple apparatus vibrated convex surfaces in contact with stationary flat surfaces at frequencies of 120 cycles or less than l cycle per second, an amplitude of 0.0001 inch, and load of 0.2 pound" (p. 135).

Memorandum presenting measurements made in the transonic speed ranges of the static-pressure position error at a distance of 0.96 chord ahead of the wing tip of both the 8-percent-thick-wing and the 10-percent-thick-wing X-1 airplanes, and at a point 0.6 maximum fuselage diameter ahead of the fuselage nose of the X-1 airplanes. Results regarding the accuracy of pitot-static heads, static-pressure error of wing-tip installation, static-pressure error of the fuselage-nose installation, and error in total pressure are provided.

A supplementary investigation on the stabilization of the Jettisonable nose section of the X-2 airplane has been conducted in the Langley 20-foot free-spinning tunnel. It was found that the nose section could be stabilized by the addition of curved fins which could be folded against the fuselage for normal flight.

Report presenting wind-tunnel testing to determine the independent effects of Mach and Reynolds numbers on the aerodynamic characteristics of a wing-fuselage combination with a wing with the leading edge swept back 63 degrees and with camber and twist. Results regarding the fuselage alone and the effects of camber and twist are also provided.

Report presenting a flight investigation of rocket-powered models at high-subsonic, transonic, and supersonic speeds to determine the zero-lift drag of fin-stabilized bodies of revolution differing in maximum diameter. All bodies had 6.04 fineness ratio and cut-off sterns with equal base area. The most favorable location out of the 20-percent, 40-percent, and 60-percent positions were evaluated for different speeds.

From Summary: "An apparatus for varying effective dihedral in flight by means of servo actuation of the ailerons in response to sideslip angle is described. The results of brief flight tests of the apparatus on a conventional fighter airplane are presented and discussed. The results of an investigation employing the apparatus to determine the tolerable (safe for normal fighter operation) range of effective dihedral on the test airplane are presented."

Results are presented for the moments and position of force centers of a series of cambered round bodies derived from a torpedo-like body of revolution. The effects of placing fins on the rear of the body of revolution are also included.

Report discussing an investigation to determine the effect of sweepback on the static and rolling stability derivatives of a series of wings with a taper ratio of 0.6 and an aspect ratio of 4. The influence on the straight-flow characteristics, rolling-flow characteristics, and aileron characteristics are provided.

Measurements are presented at Mach numbers from about 1.3 to 1.5 of reflection characteristics and the relative upstream influence of shock waves impinging on a flat surface with both laminar and turbulent boundary layers. The difference between impulse and step waves is discussed and their interaction with the boundary layer is compared. General considerations on the experimental production of shock waves from wedges and cones and examples of reflection of shock waves from supersonic shear layers are also presented.

Report presenting an investigation to determine the damping-in-roll characteristics of a 42.7 degree sweptback wing using a linearly twisted wing to represent a rolling wing. Results regarding the effect of the airfoil contour, damping-in-roll coefficient, wing-tip helix angle, and theoretical results are provided.

Report presenting an investigation of a series of flame holders designed with the objective of providing a high combustion efficiency in a ramjet combustor at an inlet air velocity of 200 feet per second, inlet-air pressure of 60 inches of mercury absolute, inlet air temperature of 200 degrees Fahrenheit, and near stoichiometric fuel-air ratio. Results regarding the preliminary experiments, two parallel rows of gutters, three rows of gutters, staggered gutters, simultaneous use of three rows and staggered gutters, use of molybdenum, and magnitude of pressure fluctuations are provided.

Report presenting the results of an experimental investigation to determine the pressure-recovery and mass-flow characteristics of single and twin NACA submerged intakes on the sides of a fuselage at various angles of sideslip. Tests were conducted with single and twin submerged intakes on a model of a fighter-type airplane.

Report presenting the boundary-layer and stalling characteristics on an NACA 64A006 airfoil section at a Reynolds number of 5,800,000. Data included measurements of lift, drag, and pitching moment, chordwise distributions of pressure, visual studies of the boundary-layer flow, and surveys of the static-pressure and velocity distribution within the boundary layer. Results regarding force and moment characteristics, pressure distributions, and boundary-layer characteristics are provided.

A model of a Consolidated Vultee Aircraft Corporation Skate 7 sea-plane was tested in Langley tank no. 2. Resistance data, spray photographs, and underwater photographs are given in this report without discussion.

Report presenting an analysis of the dynamic-lateral-stability characteristics of the Bell X-2 airplane as affected by variations in mass, aerodynamic, and dimensional parameters by means of calculations of the period and rate of damping of the lateral oscillation. Results regarding the airplane with flaps and gear retracted, airplane with flaps and gear lowered, and effects of assumed modifications to the airplane are provided.