羽生 宏人

Ammonium perchrolate (AP) is the most useful oxidizer for the solid rocket motors (SRMs) under the present situation, however it is also the source of the environmental pollution close to the launch site. It is well known that HCl is exhausted through the firing of SRMs and its concentration reaches approximately 10 to 20 mole percent of the total exhaust.`Environmentally friendly' and `High performance' are required for the next-generation SRMs. In this study, ammonium dinitramide (ADN), which has recently attracted attentions as a halogen-free oxidizer was employed for a substitution of AP and the combustion properties of the composite propellants were investigated. Thermoplastic elastomer (TP) and hydroxyl-terminated butadiene polymer (HTPB) were used as a binder for this research. Pyrotechnic sensitivity analysis was conducted to estimate the safety of TP/ADN propellants. Strand burning tests were also carried out for all samples and the burning rate and temperature profile were obtained through these experiments. It was found that the burning rate characteristics of ADN-based propellants were influenced by the binders.

The educational hybrid-rocket was successfully launched and it also landed within the predicted area. Aerodynamic characteristics of the rocket designed by students of Tsukuba University were evaluated by the wind tunnel testing with the support of Tokai University. The flight path affected by the environmental condition, especially wind direction and velocity, was simulated with the original calculation program. The altitude of the rocket was measured with the optical equipment and the apex was 123 m although the calculation indicated 198 m. We expected that the insufficient filling or the volatilization of Nitrous oxide as an oxidizer led to this result. And then, the apex was verified with a function of the oxidizer filling ratio. The results showed that 81.2 % of the oxidizer volume in comparison with the firing test condition was accumulated in the tank at the launch.

A lot of slurry fluids have an opaque substance. It is difficult to visualize using previous photograph system with a visible ray. Therefore, we use the X-ray photograph to visualize inside a slurry fluid. And also to capture three-dimensional flow structure of the slurry flow, we use two X-ray sources and detectors. Time-serial data of the particle position are obtained by particle tracking and stereo-pair matching techniques. 3-Dimensional velocity vectors inside the slurry fluid are obtained