From Introduction: "The problem of free-convection flow as produced by a body force about a flat plate in the direction of the body force was studied at the NACA Lewis laboratory and is treated in a formal and more general manner herein. The method used is somewhat similar to that used in reference 4 wherein consideration was given to the free-convection flow at high Grashof numbers in a horizontal cylinder which had a variable surface-temperature distribution. In addition, the numerical solutions of references 2 and 3 are herein extended to cover a more complete range of variables."

Report presenting an experimental investigation of the effect of oil viscosity on bearing operation characteristics using a 75-millimeter-bore cylindrical-roller inner-race-riding cage-type bearing. Results regarding DN value, oil flow, viscosity, the combination of DN and oil flow, oil inlet temperature, and improvements to cooling correlation theory are provided.

Note presenting a theoretical solution obtained for the problem of the compressive buckling of flat rectangular Metalite type sandwich plates with simply supported loaded edges and clamped unloaded edges. The solution is based on the general small-deflection theory for flat sandwich plates developed in a previous NACA report. Results regarding the stability criterion and buckling curves, correction for plasticity, and a comparison with theoretical results are provided.

From Summary: "Results of an analytical and a sea-level experimental investigation of a turbojet engine with proportional speed control are presented."

Report presenting the use of the similarity law for steady hypersonic flow about slender shapes as extended to nonsteady flows. The aerodynamic forces and moments are correlated for related shapes by means of this law. The motions of related bodies in free flight could be correlated using the hypersonic similarity parameters and additional parameters relating the inertial properties of the bodies and air densities.

"The corrosion resistance of unprotected magnesium-zinc-zirconium alloy ZK60A was determined in a marine atmosphere and in tidewater. The unprotected alloy was so rapidly attacked in tidewater that it would be of no practical value in applications subject to wetting by sea water. In the marine atmosphere the rate of corrosion was much less and the alloy should give good service if adequately protected" (p. 1).

Report presenting some preliminary calculations for airplanes of current design in order to determine the proper angles of sideslip in order to design ideal vertical tails. Existing simplified calculations for determining these values are not generally applicable to airplanes of current design, but a new solution is proposed. Results for two different airplanes are provided and suggestions for adjusting calculated sideslip values are provided.

Report presenting transient data from approximate step and sinusoidal disturbances of fuel flow on a turbojet engine operated at one constant simulated altitude and flight condition. Results regarding coefficients of differential equations, Fourier representation, frequency response, transient analysis, and a comparison of the various analytical methods are provided.

Report presenting results of axial-load fatigue tests on notched specimens of three sheet materials: 24S-T3 and 75S-T6 aluminum alloys and normalized SAE 4130 steel. Tests were run at four levels of nominal mean stress.

"Direct-reading design charts are presented for 75S-T6 aluminum-alloy flat compression panels having longitudinal extruded Z-section stiffeners. These charts, which cover a wide range of proportions, make possible the direct determination of the stress and all panel dimensions required to carry a given intensity of loading with a given skin thickness and effective length of panel" (p. 1).

"An investigation to determine the structural damping characteristics of a full-scale airplane wing was conducted by the shock-excitation method wherein the wing was loaded to a predetermined deflection and the load suddenly released. The test specimen vibrated at its fundamental bending frequency of 1.69 cycles per second. Only the first 2 or 3 cycles showed any indication of a higher frequency being superimposed upon the fundamental bending frequency. The damping was found to increase from about 0.002 to critical at an amplitude of vibration of plus and minus 0.05 inch to approximately 0.006 of critical at an amplitude of + or - 5 inches" (p. 1).

"Several common methods for curve fitting a set of data by least squares are described and evaluated. The methods are evaluated by applying them to an example taken from aerodynamics: the problem of calculating the stability parameters of an airplane from flight data. There are other points considered: application of the methods to minimization problems other than curve fitting and the question of convergence to a mere stationary point as opposed to convergence to a minimum" (p. 1).

Report presenting supersonic profiles of minimum pressure drag for a given thickness ratio and a given area created by using non-linear pressure relation and compared with minimum-drag profiles found by linearized theory. The parameters determining the airfoil shape for a given thickness ratio found by linear and nonlinear theory are presented in graphs as a function of the base pressure coefficient.

Report presenting flame speeds for methane-air, propane-air, and ethylene-air mixtures at -73 degrees Celsius and for ethylene-air mixtures at -132 degrees Celsius. The data extend the curves of maximum flame speed against initial mixture temperature previously established for the range from room temperature to 344 degrees Celsius. Results regarding velocity profile of the nozzle, flame speeds based on the outer edge of shadow, and a comparison of experimental and theoretical data are provided.

"The report presenting information on the stress problems in the analysis of pressurized cabins of high-altitude aircraft not met with in other fields of stress analysis related to aircraft. The material may be roughly divided into shell problems and plate problems, the former being concerned with the curved walls of the cabin or pressure vessel and the latter being concerned with small rectangular panels of its walls, framed by stiffeners, but not necessarily plane" (p. 1).

Note presenting a determination of the reciprocal equations relating the lift and moment acting on an airfoil due to harmonic oscillations in compressible flow to the indicial lift and moment functions for a pitching airfoil. Two functions are required to completely describe the lift or moment on the airfoil: one is used for describing the effects due to angular position of the airfoil while the other is used for describing the effects due to pitching velocity.

Report presenting an investigation of the altitude performance of a 28-inch diameter ram-jet engine using a direct-connect system in an altitude test chamber. The majority of the investigation occurred at Mach number 2 at altitudes above the tropopause (250 degrees Fahrenheit inlet temperature). Various design configurations were explored and runs were made with different types of fuel.

"An investigation was conducted in the NACA Lewis icing research tunnel to determine the characteristics and requirements of cyclic deicing of a 65,2-216 airfoil by use of an external electric heater. The present investigation was limited to an airspeed of 175 miles per hour. Data are presented to show the effects of variations in heat-on and heat-off periods, ambient air temperature, liquid-water content, angle of attack, and. heating distribution on the requirements for cyclic deicing" (p. 1).

From Summary: "A photographic technique for investigating water droplets of diameter less than 200 microns falling freely in air at temperatures between 0 C and -50 C has been devised and used to determine: (1) The shape of frozen droplets, (2) The occurrence of collisions of partly frozen or of frozen and liquid droplets, and (3) The statistics on the freezing temperatures of individual free-falling droplets."

Report presenting an investigation at Mach number 1.91 to determine the gross spreading characteristics of jets expanding from convergent and convergent-divergent nozzles using total-temperature surveys. Results regarding the preliminary development and jet spreading characteristics of the different types of nozzles are provided.

"The frequency of blade temperature to exhaust gas temperature is presented for two locations in the blade and at several operating conditions. The frequency response was determined by Fourier analysis of transient data. Two analytical methods are presented, and results are compared with experimental data. Dynamic response of turbine-blade temperature to exhaust-gas temperature exhibited the form of an approximate first-order lag" (p. 1).

Memorandum presenting the pressure recovery, mass flow, and drag of a twin-scoop inlet-body combination measured at Mach numbers 1.4 and 1.7 at zero angle of attack. Tests were made of the inlet-body combination with an ogival forebody, an ogival forebody with a small amount of bluntness near the tip, and two forebodies of elliptical longitudinal section. Results regarding the effect of forebody bluntness on pressure recovery, effect of forebody bluntness on mass-flow ratio, and the effects of forebody bluntness on drag are provided.

Report presenting a low-speed investigation in the stability tunnel to determine the static longitudinal stability and control characteristics of two wing-fuselage combinations equipped with wing-tip controls of half-diamond and half-delta plan form. Results regarding the effect of control area and plan form on control characteristics and on trim characteristics are provided.

Report presenting testing on the NACA 16-009 airfoil and on eight airfoils of the NACA 6A series, which shows that the chordwise loading due to lift at a Mach number of 1.0 is insignificantly affected by thickness distribution within the range of airfoil shapes presented and only slightly affected by thickness. Results regarding the experimental loading on symmetrical airfoils, method of estimating pressure distribution, experimental loadings on cambered airfoils, and scope of method are provided.