This paper gives the detailed description of the piston driven shock tube built at Kyoto University and some results of its performance tests. The compression processes are studied experimentally and compared with the theoretical predictin reported in the reference 2. The shock speed and the flow duration time are measured by electrostatic probes. The Mach numbers of up to 24 in air at the initial pressure of 0.09-10mmHg and the flow duration times of 20-150μs are obtained.
The nozzle flows of weakly ionized plasmas of helium and argon are considered. It is assumed that the plasmas are composed of neutral atoms, singly ionized positive ions and electrons, that the flows are quasi-one-dimensional, and that the chargeneutrality is almost maintained throughout the nozzle. The flows start from a nonequilibrium state with regard to the energy and the ionization. As they flow through the nozzle, the electron-ion recombination and the adjustment of the temperature difference between the electron gas and the atom-ion gas occur. The electron temperature, the rate of ionization and the other flow parameters along the nozzle axis are calculated.
Actual rocket bodies have a finite bending stiffness. Low bending stiffness reduces the pitching moment of the body in comparison with the case where the rocket body is assumed to be rigid and this tendency becomes stronger as the velocity increases. This paper treats the case of the single step rocket of finite bending stiffness and gives an approximate equation of the righting pitching movent. This approximation is expected to be also applicable to multi-step rockets.
Natural frequencies of rectangular plates in the post-buckling states are analytically and experimentally studied as a fundamental study of the supersonic panel flutter. For panels which are simply supported for bending and constrained for in-plane displacement at four edges, the natural frequencies of the first and second modes are approximately calculated by using two modes approximation and GALERKIN method. The variation of the natural frequencies of a square plate with the amount of the buckling deformation is shown in figures for four cases of the in-plane stress condition of the two directions. For comparison with experiment, the first and second natural frequencies of clamped rectangular panels are obtained by two modes approximation. Furthermore, a higher approximation is studied for the lowest symmetrical mode, and the eflect of initial imperfection of the plate is also studied. Experimental results for a square panel firmly clamped at four edges are in good agreement with the present analytical results.
An optimization procedure of the thrust programming is stated for a rocket which is required to reach a maximum altitude with given initial and propellant weight. The problem of thrust programming is treated as that of the pressure programming. The chamber pressure is assumed as a polygonal function of time. The problem is solved numerically by a multipe-parameter optimization technique. The analysis is performed on a rocket with arbitrary drag coefficient flying in a vertical plane wherein the gravity and the properties of atmosphere are known as functions of altitude. The relation between this method and the design procedure of a sounding rocket is stated.