Following the preceding paper which dealt with the buckling pressure of spherical shells, results of measurements of deformation pattern and strain distribution up to the critical pressure of the shells are reported. Some of the results obtained are as follows; that is, the pre- and postbuckling deformation patterns are axisymmetrical, the prebuckling deformation modes are not constant but vary with the loading, the number of waves in the meridional direction increases with the geometrical parameter, deflections up to the occurrence of buckling are small especially for the shells of large geometrical parameter, and the so-called boundary layer of deflection is generated when the geometrical parameter becomes larger. The detailed discussions on the results seem to contribute to make the mechanism of the buckling of spherical shells subjected to external pressure clear.
Three dimensional analysis is made with respect to electric power consumption of the electron bombardment ion engine at an orbital transfer or a station keeping of an artificial satellite. The optimum position for the ion engine operation is determined, and three types of control are possible to compensate for a change of thrust level. Variations of power are calculated, and the most advantageous control method is obtained. It is clarified that propellant fllow control, which is usually adopted, does not necessarily give optimum one. The change of accelerating voltage does not need more propellant, but may go unsteble owing to changes in position of plasma boundary. When the ion production cost is changed, the shift to the optimum point is required to operate at minimum power consumption.
In this paper, a method to measure the wind velocity by ultrasonic techniques is presented. The principle used is as follows: Since the ultrasonic beam is deflected by wind, the uniform wind velocity can be measured by the change of received acoustic pressure. When the continuous wave is used, the relation between the received acoustic pressure and the wind velocity is determined through the directivity characteristics of ultrasonic transmitter and receiver, and the effects of wind direction and so forth are also investigated. The agreement between the theoretical values and the experimental results is considered to be extremely good.
Vibration and supersonic flutter characteristics of plate wings with constant thickness are systematically presented using the direct method of the variational problem. Especially, the influences of the wing planform, i.e. the sweep back angle, the taper ratio and the aspect ratio, on the supersonic flutter characteristics are investigated in detail and the influences of the wing thickness and flight altitude are also shown. Furthermore, the high frequency flutter is systematically studied.