Only part of the flow information in hypersonic inward-turning inlets can be got with a conventional observation method. In this paper, simultaneous surface tuft flow visualization technique, high-speed Schlieren imaging, and surface pressure measurements were adopted to comprehensively observe the dynamic flow in a hypersonic inward-turning inlet/isolator model at Mach 5.9. When a light-blockage was pre-set in the inlet, the surface tuft flow visualization on the forebody displayed the flow characteristics of the inward-turning inlet from un-starting to re-starting dynamically, providing evidence for self-starting of the inlet at similar conditions. Moreover, tufts on the inner surface of the isolator showed the propagation of the choked flow induced by the light-blockage. Un-start flow was also initiated by a throttling cone-plug, and shock wave oscillations (or buzz) appeared. The special flow pattern near the inner surface of the isolator in the initial phase of the buzz was detected. The surface tuft movie provided evidence of the upstream-propagating shock in the isolator during the buzz. The frequencies of the shock wave oscillation obtained by the observation methods and surface pressure measurements were consistent with each other.
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