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."

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."

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

From Introduction: "The NACA Lewis laboratory has undertaken a program of analytical study to evaluate the effect on turbojet-engine performance of extracting energy from several points in the cycle. The program included an investigation of the effects of air bleed from the compressor outlet, hot gas bleed from the turbine inlet, hot gas bleed from the turbine outlet, and shaft power extraction (references 1 to 4). "

For compressible flow with friction in a cylindrical pipe the momentum, continuity, and heat-transfer equations are examined to determine whether an increase in Mach number ("thermal" Laval nozzle) is obtainable through heat conduction from the gas through the pipe walls. The analysis is based on the assumption that the wall temperature is negligibly small in comparison with the stagnation temperature of the gas. The analysis leads to a negative result. When the gas cooling is increased by also considering radiation to the wall, a limited region at high temperatures is obtained where Mach number increases were theoretically possible. Obtaining this condition practically is considered impossible.

"An investigation of the heat transfer from an airfoil in clear air and in simulated icing conditions was conducted in the NACA Lewis 6- by 9-foot icing-research tunnel in order to determine the validity of heat-transfer data as obtained in the tunnel. This investigation was made on the same model NACA 65,2-016 airfoil section used in a previous flight study, under similar heating, icing, and operating conditions. The effect of tunnel turbulence, in clear air and in icing was indicated by the forward movement of transition from laminar to turbulent heat transfer" (p. 1).

Note presenting an experimental investigation in which measurements were made of the turbulent boundary layer of a two-dimensional unswept wing and a comparable wing swept 45 degrees. The results indicate the applicability of simple sweep theory for determining turbulent boundary-layer growth on the swept wing for a lift coefficient of zero.

Report presenting a theoretical investigation to determine the effect on the lateral stability of a typical high-speed fighter airplane of an autopilot sensitive to yawing velocity. The effects of inclination of the gyro spin axis to the flight path and of time lag in the autopilot were also determined. The damping of lateral oscillation of the airplane for all flight conditions studied should satisfy the Air Force-Navy criterion when the proposed autopilot is installed.

"An empirical method for the determination of the area, rate, and distribution of water-drop impingement on airfoils of arbitrary section is presented. The procedure represents an initial step toward the development of a method which is generally applicable in the design of thermal ice-prevention equipment for airplane wing and tail surfaces. Results given by the proposed empirical method are expected to be sufficiently accurate for the purpose of heated-wing design, and can be obtained from a few numerical computations once the velocity distribution over the airfoil has been determined" (p. 1).

Report issued by the U.S. Bureau of Mines on the known recoverable reserves of coking coal in Floyd County, Kentucky. The investigation includes a study on the properties of coal and coal blends found in the area. This report contains maps and tables.

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.

Report presenting an experimental investigation of the pressure distribution about a circular cylinder at yaw angles of 0, 15, 30, 45, and 60 degrees and a variety of Reynolds numbers. Testing indicated that for the range of Reynolds number near and above the critical value, the flow and force characteristics of a yawed circular cylinder cannot be determined only by the component of flow normal to the axis of the cylinder.

Note presenting an investigation to determine the distribution of water pressure on seaplanes, in which a rectangular flat-plate model 1 foot wide and 5 feet long was subjected to smooth-water impact and planing tests. Initial impact conditions and maximum pressures are presented in tables and figures for all impacts, together with time histories of the pressure distribution, draft, vertical velocity, vertical acceleration, and wetted length.

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 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.

"An experimental investigation was conducted to determine the temperature profile downstream of a heated-air jet directed perpendicularly to an air stream. The profiles were determined at several positions downstream of the jet as functions of jet density, jet velocity, free-stream density, free-stream velocity, jet temperature, and orifice flow coefficient. A method is presented which yields a good approximation of the temperature profile in terms of dimensionless parameters of the flow and geometric conditions" (p. 1).

It is shown that the ordinary Joukowski formula for lift force of cascade blades in incompressible flow can be applied to the case of subsonic compressible flow with sufficient accuracy, provided that the density in the formula is taken as the arithmetic mean of the densities far ahead of and behind the cascade.

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.

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.

From Summary: "A flight instrument that uses electric means for measuring the droplet-size distribution in above-freezing clouds has been devised and given preliminary evaluation in flight. An electric charge is placed on the droplets and they are separated aerodynamically according to their mass. Because the charge placed on the droplets is a. function of the droplet size, the size spectrum can 'be determined by measurement of the charge deposited on cylinders of several different sizes placed to intercept the charged droplets. An expression for the rate of charge acquisition by a water droplet in a field of coronal discharge is derived."

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.

Monthly report of the U.S. Geological Survey's trace element investigations including an outline of field work, laboratory work, and staff activities that have been completed or are in process.

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.

Abstract: Results of detailed mapping of the Salt Wash sandstone member of the Morrison formation in the Uravan and Gateway districts, Montrose and Mesa Counties, Colo., suggest that large areas containing both lenticular bedding in the ore-bearing sandstone and persistently altered mudstone beneath the sandstone are generally favorable for carnotite deposits.