Toru Shimada

By employing X-ray photography and image analyses, internal three-dimensional flow field of a simulated solid propellant slurry containing lead sphere tracers is visualized in a double circular cylinder container. X-rays are projected on to the slurry flow from two directions perpendicular to each other and penetration images are recorded by a flat panel detector and an X-ray image intensifier. By suppressing the mutual interference of the X-rays, the two-directional X-ray photography has been successfully conducted. Using the time series data of the X-ray images from the two directions, the identification of each tracer particle in space and time has been done and their three-dimensional paths have been computed. From these procedures, the flow field or the velocity field inside the opaque slurry flow has been estimated.

Transient aerodynamic characteristics of the flows around bodies of parachute-like configuration are numerically analysed from solution of the Navier-Stokes equations. The computational method is mainly based upon combination of effective and efficient techniques recently developed in the field of computational fluid mechanics. The results show that the flow behavior around a mouth plays a key role in determining the maximum peak drag acting of the parachute-like body in the starting period from the rest and also a vent is effective in controlling the starting peak of the drag.