Note presenting a theory of stall propagation in a cascade of airfoils of high solidity, which includes the effects of finite blade chord and of the boundary-layer response to changes in angle of attack. For a stationary circular cascade and a single-stage axial-flow compressor, the theory predicts propagation velocities within 25 percent over a wide range of wave lengths.

Note presenting an evaluation of the existing theories of linearized tire motion and wheel shimmy. A series of systematic approximations to the summary theory is developed for the treatment of problems too simple to merit the use of the complete summary theory. Procedures are discussed for applying the summary theory and its systematic approximations to the shimmy of more complex landing-gear structures than have previously been considered.

Report presenting a method for obtaining influence coefficients for thin low-aspect-ratio wings of built-up construction. Symmetric and anti-symmetric load-support conditions are considered. A simple method is given for taking account of attachment to a flexible fuselage.

Note presenting an investigation indicated that nominal additions of 0.1, 1.0, and 5.0 weight percent copper and magnesium to aluminum have significant effects on damping behavior. An internal-friction peak at abotu 125 degrees Celsius was observed in aluminum containing 1 percent copper and is believed to result from the interaction of dislocations and impurity particles. The internal friction during plastic deformation was sensitive to strain rate, amount of strain, alloy content, heat treatment, temperature, and the frequency at which the measurements are made.

Note presenting an instrument of fairly simple design for measuring time correlation functions of two stationary random electrical signals. It is intended primarily for use in problems connected with aerodynamically produced acoustic fields but has suitable properties for application to a rather wide range of aerodynamic problems involving turbulent fields.

Paper presenting a preliminary account of some research conducted on the general problem of flow separation. The research is fundamental in nature, partly theoretical, and partly experimental. Measurements are made of subsonic and supersonic speeds for a variety of two dimensional model shapes involving separation.

Report presenting flight testing of a model of a cruciform missile configuration with a low-aspect-ratio wing equipped with flap-type controls in order to determine the stability and control characteristics while rolling at about 5 radians per second. Results indicated that if the ratio of roll rate to natural circular frequency in pitch is not greater than about 0.3, the motion following a step disturbance in pitch essentially remains in a plane in space. Results regarding time histories, normal force due to angle of attack, pitching moment due to angle of attack, damping, and control effectiveness are provided.

"A theoretical investigation has been made of the Saint-Venant torsion of certain composite bars. These bars are composed of two materials -- one material in the form of a thin-walled cylindrical shell and the other material in the form of a core which fills the interior of the shell and is bonded to it. An approximate boundary-value problem is formulated on assumptions similar to those of the theory of torsion of hollow thin-walled shells (Bredt theory)" (p. 771).

Report presenting an acceleration control that operates on fuel flow and uses directly measured acceleration as the control signal as applied to an axial-flow turbojet engine. A study to determine the feasibility and dynamic characteristics of the control was undertaken. Results regarding the open-loop characteristics and closed-loop characteristics are provided.

Report presenting pressure-drag coefficients and the changes in these coefficients with mass-flow ratio, which have been measured in tests of six open-nose conical cowls at an angle of attack of 0 degrees. Testing occurred in the Ames 8 by 8-inch supersonic wind tunnel at a range of Mach numbers. Results regarding pressure distributions, change in cowl pressure drag with mass-flow ratio, cowl pressure drag at a given mass-flow ratio, and changes in cowl pressure drag with mass-flow ratio as a function of Mach number are provided.

Report presenting the zero-lift drag of several wings obtained at supersonic Mach numbers in free flight with rocket-propelled models. The wings tested all had the same exposed area, mounted on the same basic body configuration, and had one of four different types of wings.

Report presenting an investigation in the 8- by 6-foot supersonic tunnel to determine the external-stream effects on the gross thrust and pumping characteristics of ejectors operating at off-design Mach numbers. Results regarding the pumping, thrust, and base characteristics, boattail drag characteristics, and stream effects on jet thrust for typical ejector installations are provided.

Memorandum presenting rudder-pulse maneuvers performed with a swept-wing fighter-type airplane at altitudes from 30,000 to 43,000 feet over a Mach number range of 0.71 to 1.48 to determine the lateral stability characteristics relative to the stability axes, in general, and the lateral derivative characteristics, in particular. Four configurations were employed; three involves different vertical tails with varying aspect ratio or area and the fourth employed a large tail with an extension of the wing tips.

Report presenting an investigation of three phases: an experimental investigation of a thin airfoil with blowing over a trailing-edge flap, a comparison of the results of the experimental investigation with the results of other similar investigations, and a theoretical study of the relationships among the air-flow and power parameters for the general blowing case. The investigation utilized a two-dimensional model of the NACA 0006 airfoil equipped with a nose flap and six alternate trailing-edge flaps.

A series of neutron multiplication measurements were made on assemblies of Pu metal (density 15.8 g/cm/sup 3/) in order that a safe melting crucible could be designed for charges of 10 kg or more. Suitable ingot shapes and masses that could be rolled into sheets were determined. Final charge limits must be determined by making in situ measurements with the actual production furnace when the furnace and crucible are compieted. (H.G.G.)

A new back-emf method for measuring the thermodynamic emf of molten salt cells of the type M/MCl/sub 2/ in molten salt solvent/Cl/sub 2/ is presented. Decomposition potentials are measured in the course of the thermodynamic emf determination. The systems PbCl/sub 2/-ZrCl/sub 2/, LiCl-KCl eutectic, LiCl-KCl- NdCl/sub 3/, MgCl/sub 2/ in LiClKCl and NaCl, SnCl/sub 2/, KCl, and PbCl/sub 2/, and ZnCl/sub 2/ in LiClKCl eutectic were studied. The thermodynamic emf's obtained by the back-emf method are in good agreement with values calculated from independent thermochemical data. Thus Raoult's law is thought to apply in these simple systems to within a factor of two in the activity coefficient. (auth)

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The package boiler was operated at a maximum steam rate of 1750 Ib/hr at 1500 psi. The operation of the pumps, relief valves, gages, and pressure controller was checked. The time required for the boiler to come up to full operation was 15 to 20 min. On the basis of the test the boiler is considered to meet the manufacturer's specifications. (auth)

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Much study has been devoted to the motion of shafts in lubricated journal bearings. In contrast, the work done on the motion of shafts in unlubricated or dry bearings is negligible. The reason is obvious: in most applications, lubrication of the bearings is relatively simple. This is not the case in nuclear power plant appliciltion where bearings operate in low viscosity primary coolants of liquid metal or water without the benefit of coolant contaminating lubricants. For this reason, an analytical study was made to determine what motions would be excited in a shaft mounted in a dry bearing. The study splits naturally into two parts: (a) the shaft maintains continuous contact with the bearing, either rolling or sliding or a combination of the two; (b) the shaft dances (or chatters) about the bearing in a series of impacts. Typical motions in each of these cases (rolling oscillations, sliding oscillations, stick- slip oscillations, chatter) are calculated and plotted. Except for the stick- slip oscillation, none of the motions studied is self-sustaining; rolling and sliding oscillations will damp out due to frictional and other losses, and chatter degenerates into a rolling whirl of the shaft around the bearing. (auth)

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