Shock-wave equations have been evaluated for a range of Mach number in front of the shock from 1.05 to 4.0. Mach number behind the shock, pressure ratio, derivation of flow, and angle of shock are presented on charts. Values are also included for density ratio and change in entropy.

Report presenting knock testing of a sensitive fuel and a relatively insensitive fuel in a full-scale air-cooled cylinder. Six engine variables were investigated: fuel-air ratio, compression ratio, inlet-air temperature, spark advance, exhaust pressure, and cylinder temperature.

Note presenting three internally cooled exhaust valves with the same external dimensions but different throat designs were investigated to determine a method of obtaining increased coolant-flow area with increasing stresses. The valves were statistically loaded to simulate stresses in the throat region caused by valve closure.

Note presenting a discussion of the integral relations for flow of the boundary-layer type. It is shown that the characteristic laws of spread of jets, wakes, and so forth, can be obtained directly for the laminar case and, with the help of dimensional reasoning, for the turbulent case as well. Measurements of the mean velocity, the intensity and scale of the turbulent fluctuations, and of the turbulent shear in a two-dimensional mixing zone are presented.

Report presenting the results of an investigation of a specific tail configuration in the 15-foot free-spinning tunnel in order to supplement the existing published data on hinge moments of elevators and rudders in spins. Hinge-moment measurements are presented for a balanced elevator equipped with trim tabs and for a balanced rudder. Results regarding elevator hinge moments, rudder hinge moments, and application of hinge-moment data are provided.

From Summary: "Axial fatigue tests at zero mean stress have been made on 0.032- and 0.064-inch 24S-T and 0.032-inch 75S-T sheet-metal specimens 1/4, 1/2, 1, and 2 inches wide without a hole and with central holes giving a range of hole diameter D to specimen width W from 0.01 to 0.95. No systematic difference was noted between the results for the 0.032-inch and the 0.064-inch specimens although the latter seemed the more consistent. In general the fatigue strength based on the minimum section dropped sharply as the ration D/W was increased from zero to about 0.25. The plain specimens showed quite a pronounced decrease in fatigue strength with increasing width. The holed specimens showed only slight and rather inconclusive evidence of this size effect. The fatigue stress-concentration factor was higher for 75S-T than for 24S-T alloy. Evidence was found that a very small hole would not cause any reduction in fatigue strength."

"The theory of small disturbances is applied to the calculation of the pressure distribution and drag of a closed body of revolution traveling at supersonic speeds. It is shown that toward the rear of the body the shape of the pressure distribution is similar to that for subsonic flow. For fineness ratios between 10 and 15 the theoretical wave drag is of the same order as probable values of the frictional drag" (p. 1).

Report presenting information regarding the velocity potential, lift force, moment, and propulsive force on a two-dimensional airfoil in a stream of periodically varying angle of attack, as well as an application of the theoretical results.

This report summarizes the work that has been carried on in the experimental investigation of the problem of general instability of stiffened metal cylinders subjected to pure bending at the C.I.T. This part of the investigation included tests of 46 sheet-covered specimens. The most significant result was the determination of a new design parameter for the case of a stiffened metal cylinder subjected to pure bending.

"This is the third of a series of reports covering an investigation of the general instability problem by the California Institute of Technology. The first five reports of this series cover investigations of the general instability problem under the loading conditions of pure bending and were prepared under the sponsorship of the Civil Aeronautics Administration. The succeeding reports of this series cover the work done on other loading conditions under the sponsorship of the National Advisory Committee for Aeronautics" (p. 1).

From Introduction: "This paper deals only with the aerodynamics of the fan proper and demonstrates the manner in which the radial distribution of axial velocity of fluid through a fan is governed by geometry of the fan itself."

Note presenting results of a flight investigation conducted on a fighter-type airplane to determine the factors which affect the loads and load distributions on the vertical tail surfaces in maneuvers. An analysis is made of the data obtained in steady flight, rudder kicks, and fishtail maneuvers.

Note presenting data from flight measurements of the meteorological factors related to the intensity of icing conditions. The physical factors that establish the distribution of liquid water in clouds of various types are discussed and the results of the analysis are used to formulate certain rules for the forecasting of icing intensity. Discussion of the results includes the problem of forecasting icing conditions and the problem of defining the physical characteristics of icing conditions for the purpose of the design of ice-protection equipment.

Report presenting a method for determining, by step-by-step integration, the trajectories of water drops around any body in two-dimensional flow for which the streamline velocity components are known or can be computed. The equations are presented in general form and then water-drop trajectories are calculated about a 12-percent-thick symmetric Joukowski profile.

Report presenting a flight investigation of a scout-bomber airplane with 4.7 degrees and 10 degree geometric dihedral in the wing outer panels in order to obtain flight test results pertaining to the upper limit of the wing-dihedral angle for satisfactory handling qualities. No unusual or undesirable lateral control characteristics were observed with the combinations of stability parameters obtained with the two dihedral angles used.

Report presenting the results of high-speed wind-tunnel research on the effects of modifications to the horizontal tail profile on the static longitudinal stability and control of a pursuit airplane at high speeds. Two symmetrical stabilizers, two flat-sided elevators, and three elevators with bulged profiles were investigated. The pitching-moment and elevator hinge-moment characteristics with various tails are shown.

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 solution is presented for the problem of the buckling of curved rectangular panels subjected to combined shear and direct axial stress. Charts giving theoretical critical combinations of shear and direct axial stress are presented for panels having five different length-width ratios. Because the actual critical compressive stress of rectangular panels having substantial curvature is known to be much lower than the theoretical value, a semiempirical method of analysis of curved panels subjected to combined shear and direct axial stress is presented for use in design" (p. 1).

Report presenting six numerical examples for steady, two-dimensional, compressible, nonviscous flow in centrifugal compressors with straight blades, the center lines of which generate a right circular cone when rotated about the axis of the compressors. A seventh example is presented for incompressible flow. Correlation equations are developed whereby the flow conditions in any impeller with straight blades can be determined for all operating conditions.

Report presenting an investigation to obtain a record of any chemical changes directly associated with knock in a spark-ignition engine on a greatly magnified time scale by means of coordinated high-speed motion pictures and spectrograms.

"This is the fourth of a series of reports covering an investigation of the general instability problem by the California Institute of Technology. The succeeding reports of this series cover the work done on other loading conditions under the sponsorship of the National Advisory Committee for Aeronautics. This report is to deal primarily with the continuation of tests of sheet-covered specimens and studies of the buckling phenomena of unstiffened circular cylinders" (p. 1).

Report presenting design charts for 24S-T and 75S-T aluminum-alloy flat compression panels with longitudinal extruded Y-section stiffeners. Comparisons are also made among panels designed from these charts and 24S-T aluminum-alloy panels with formed Z-section stiffeners designed from available design charts.

Report presenting an investigation to determine the effects of compressibility on the aerodynamic characteristics of a 5-inch-chord NACA 16-009 airfoil with a 32.9-percent-chord flap with a nose overhang and an unsealed gap. Airfoil lift and pitching moment and flap hinge moments were obtained for a range of angles of attack, flap angle ranges, and Mach numbers.

Report presenting the optical principle of the NACA ultrahigh-speed camera. Simplified sketches are included illustrating the optical principle and main design features of the camera, but without minor design details. A detailed description of the camera is provided as well as some sample photographs taken with the camera.