バリスティック・レンジによる極超音速流実験 (第1報)

In order to investigate the atomic/molecular radiation from hypersonic flowfields, a small plastic projectile weighing 0.4g is accelerated up to higher than 5km/s using a ballistic range. A spectral measurement is done when a projectile passes through the test section, emitting radiation from its strong shock layer: The spectrographic data are obtained in the wavelength range 330 to 650nm. To study the radiation emission with high time-resolution, a high-speed shutter system using an image intensifier and a pulse generator is set up, giving a spatial distribution of radiation intensity in the shock layer. Another measurement is also done, taking framing pictures of the projectile during its flight. For the purpose of convenience, a transformation from the photographic to numerical data is performed, using a digital data-processing system composed of a CCD camera and an image processor. The measured results indicate that such measurement systems can be used in the study of reentry problems in a laboratory environment, after improving of the ballistic range performance.