This report presents the results of flight measurements of longitudinal stability and control characteristics made on a swept-wing jet aircraft to determine the origin of the pitch-up encountered in maneuvering flight at transonic speeds. For this purpose measurements were made of elevator angle, tail angle of attack, and wing-fuselage pitching moments (obtained from measurements of the balancing tail loads).

Report presenting force, moment, pressure-distribution, and boundary-layer measurements for a series of five airfoil sections. The stalling characteristics of the three airfoil sections at low speeds can be separated into three types. A deeper discussion of the role of boundary-layer flow and separation processes in relation to stalling and the sensitivity of stall to factors that influence boundary-layer growth is provided.

Note presenting the results of the experimental investigation of the self-excited torsional oscillation of an NACA 0006 airfoil suspended elastically. The relationship between the torsional oscillation and the shedding of vortices was investigated for this airfoil. Two types of oscillation phenomena were found: one was exhibited by cases with angles of attack just above stall and one was exhibited by cases with higher angles of attack.

Report presenting tables and curves that give values of the induced-upwash-velocity factors, due to jet boundary, at the horizontal center plane of a closed circular wind tunnel and of a closed bipolar wing tunnel. The application of induced-upwash-velocity factors to the determination of jet-boundary corrections is also discussed.

Note presenting a rapid method for designing turbomachine blades of a given turning and a desirable blade-thickness distribution for a compressible non-viscous fluid flow along an arbitrary stream filament of revolution. The method is illustrated with the design of several turbine cascades of highly cambered thick blades.

"The width of a Debye-Scherrer line under the combined influence of spectral width of the primary radiation and of the small size of the crystal grains is calculated, omitting all geometric causes of line broadening. The shape of the crystals is assumed spherical, with the same diameter for all grains. The orientation is assumed to be random, with negligible statistical fluctuations" (p. 1).

Note presenting an overview of bent crystal lamellae, which may consist of individual blocks, spaced somewhat irregularly and with a mutual angular disorientation. In this case, the x-ray intensities of the individual blocks will simply be added. A study was done to determine if there was any difference between diffraction by a bent lamella and by an array of irregularly spaced blocks arranged in a circle.

Report presenting equations derived for the equilibrium operation of a turbine-propeller engine in terms of parameters used in turbine- and compressor-performance maps. By use of the analytical relations, geometric, thermodynamic, and aerodynamic relations among compressor, turbine, and exhaust nozzle may be calculated.

Note presenting an investigation of the maneuvering tail load requirements conducted using a Lockheed Constitution airplane. An analysis of the forces exerted by the pilot, the control motions, and the airplane responses for a series of maneuvers occurred. Results regarding pitching maneuvers, yawing maneuvers, rolling pull-outs, and structural deflections are provided.

Report presenting an analysis of the supersonic flow in two two-dimensional high-solidity cascades and in a partly supersonic symmetrical nozzle. A method is developed for the determination of the supersonic flow along stream surfaces of revolution in turbomachines. In addition to their use in direct problems, the equations can be used to design blade elements in supersonic flow along an arbitrary stream filament of revolution in turbomachines.

Report presenting expressions for the velocity potential and the lift and moment for thin, oscillating, arrowhead-type wings with supersonic edges moving at a constant supersonic speed.

Report presenting linearized, compressible flow analysis as applied to the study of quasi-conical supersonic wing theory. Single-integral equations are derived which relate either the loading to the shape of a lifting surface or the thickness of a symmetrical wing to the pressure distribution for triangular wings with subsonic leading edges. For the nonlifting case, it is shown that for a specified pressure distribution the theory does not always predict a unique thickness distribution.

Note presenting the calculation of the increase in the resistivity of copper under cold-working. The increase is assumed to be caused by dislocations surrounded by a long-range electrostatic field that scatters the conduction electrons.

From Introduction: "This report covers three phases of investigation of the problem of improving take-off performance by use of flaps."

Report presenting formulas obtained by means of the linearized supersonic-flow theory for the lateral force due to sideslip, the yawing moment due to sideslip, and the rolling moment due to sideslip for normal tail arrangements consisting of rectangular, triangular, and sweptback vertical tails of arbitrary taper and sweep mounted symmetrically on a horizontal tail of arbitrary shape.

From Introduction: "This paper is concerned with the derivation of expressions for the velocity potential and associated forces and moments for oscillating triangular wings in supersonic flow."

Report presenting experimental studies conducted to evaluate the formation, under transient temperature conditions, of sulfide films on heated steel specimens immersed in solutions of free sulfur in cetane and to establish the necessary sulfide-film thickness for effective lubrication under static-friction conditions. Results regarding the chemical investigation, static-friction investigation, and significance of both investigations are provided.

Note presenting an analysis of the laminar compressible boundary layer over an insulated flat plate moving with a time-dependent velocity. A group of parameters arise which, if large, provide that the classical "starting from rest" solution applies, and if small, that the motion is quasi-steady. In various problems of unsteady boundary-layer motion, the parameters provide an advance criterion as to whether the flow need be considered essentially unsteady or whether the motion may be considered quasi-steady.

From Introduction: "The present paper is intended to give some features of flutter in bending alone and contains results of analyses made to determine some effects of wing mass-density ratio, angle of sweepback, length-semichord ratio, and Mach number. Some relations of pure-blending flutter to the conventional bending-torsion flutter are also given."

Report presenting an analytical investigation to determine the applicability of the Zehnder-Mach interferometer to two-dimensional cooled-boundary-layer studies. The main factor governing a test section design other than flow characteristics is the estimate of how close to the wall the boundary layer need be studied.

Report presenting a study to evaluate the importance of the type of air-compression process on the loads produced on an oleo-pneumatic landing gear during impact and to determine the type of air-compression process actually obtained during drop tests. Results regarding the importance of the type of air-compression process on landing-gear loads and air-compression process obtained during drop tests are provided.

Report presenting solutions for axially symmetric flow through an impeller with and without inducer vanes, which were obtained by relaxation methods using an analysis in the report. The fluid was considered inviscid and incompressible. Plots of streamlines, lines of constant velocity, and lines of constant tangential blade force are presented and discussed.

Note presenting a procedure based on the kinetic-energy equation and an extended form of the momentum equation that has been devised for calculating the development of turbulent boundary layers, in adverse pressure gradients, for that class of flows for which the fluid density in all points and total pressure outside the boundary layer are invariant. Results regarding two-dimensional flow, conical-diffuser flow, separation, and the application of the procedure are provided.

Report presenting the three partial differential equations of the laminar boundary layer for two-dimensional steady-state compressible flow, which have been transformed into two ordinary differential equations by the method of Pohlhausen, Falkner, and Skan. A total of 58 cases have been solved numerically by the method of Picard. For each of the cases, the displacement, momentum, and convection thicknesses, as well as Nusselt number and coefficient of friction at the wall, were computed.