"Evaluation of the rotating multicylinder method for the measurement of droplet-size distribution, volume-median droplet size, and liquid-water content in clouds showed that small uncertainties in the basic data eliminate the distinction between different cloud droplet-size distributions and are a source of large errors in the determination of the droplet size. Calculations of the trajectories of cloud droplets in incompressible and compressible flow fields around a cylinder were performed on a mechanical analog constructed for the study of the trajectories of droplets around aerodynamic bodies" (p. 1).

Report presenting a flight investigation conducted to establish the heat requirements for ice prevention on aircraft windshields mounted on the forebody of an airplane at several angles. Electrically heated windshields were used in order to provide accurate measuring of heat input to the windshield. Results regarding the quantity of heat provided, amount of water collection, ideal windshield angle, ranges in airplane velocity, and icing conditions are provided.

Time constants that characterize engine speed response of a turbine-propeller engine over the cruising speed range for various values of constant fuel flow and constant blade angle were obtained both from steady-state characteristics and from transient operation. Magnitude of speed response to changes in fuel flow and blade angle was investigated and is presented in the form of gain factors. Results indicate that at any given value of speed in the engine cruising speed range, time constants obtained both from steady-state characteristics and from transient operation agree satisfactorily for any given constant fuel flow, whereas time constants obtained from transient operation exceed time constants obtained from steady-state characteristics by approximately 14 percent for any given blade angle.

Memorandum presenting the results of a wind-tunnel investigation of the damping in pitch of a model triangular wing with an aspect ratio of 4 combined with a slender pointed body. The investigation was conducted at Mach numbers from 0.10 to 0.95 for Reynolds numbers of 550,000 and 1,250,000 with additional data obtained at Reynolds numbers of 3,000,000 and 6,000,000 at Mach number 0.23. Results regarding the effects of oscillation amplitude, Mach number, Reynolds number, angle of attack, frequency, and pitching axis position are provided.

Report presenting the low-speed stalling and lift characteristics of the Douglas D-558-II airplane measured in a series of 1 g stalls in four different airplane configurations. Various combinations of landing gear, flaps, inlet-duct flaps, and slats were tested at a range of altitudes.

The characteristics of a wedge static-pressure sensing element with various holder configurations were determined and compared with the characteristics of the conventional tube. The probes were tested over a range of Mach number from 0.3 to 0.95 and at various pitch and yaw angles. The investigation showed that the spike-mounted wedge sensing element has a pressure coefficient comparable with the conventional subsonic static-pressure probe and the pressure coefficient of the wedge varied less than that of the conventional probe for corresponding change of yaw angle.

Performance of a J47D (RX1-1) turbojet engine equipped with afterburner, variable-area exhaust nozzle, and integrated electronic control was determined over a range of flight conditions. These data were obtained with the electronic control both operative and inoperative. For operation with scheduled exhaust nozzle area, the minimum specific fuel consumption of 1.15 pounds of fuel per hour per pound of net thrust occurred at about 7200 rpm at altitudes from 5000 to 25,000 feet at a flight Mach number of 0.19.

Report presenting testing using rocket-powered models to provide an experimental comparison with linearized theoretical calculations for zero-lift drag of sweptback tapered wings with thin, symmetrical, double-wedge airfoil sections. The theory compared favorably with experimental results over most of the test range. Taper was generally found to increase wing drag at low supersonic speeds but reduced drag at higher speeds.

The time-average characteristics of boundary layers over a flat plate in nearly quasi-steady flow are determined. The plate may be either insulated or isothermal. The time averages are found without specifying the plate velocity explicitly except that it is positive and has an average value.

The present paper is a continuation of a theoretical investigation of the stability of the laminar boundary layer in a compressible fluid. An approximate estimate for the minimum critical Reynolds number, or stability limit, is obtained in terms of the distribution of the kinematic viscosity and the product of the mean density and mean vorticity across the boundary layer. The extension of the results of the stability analysis to laminar boundary-layer gas flows with a pressure gradient in the direction of the free stream is discussed.