A MHz rate imaging system for study of turbulent and time evolving high speed flows

We present a second generation MHz frame rate imaging system, based on a custom fabricated "pulse-burst" laser and a commercial CCD framing camera. The utility of the system for high-speed flow visualization is demonstrated in a Mach 1.3 axisymmetric jet. Complete 17 frame image sequences are used to explore the evolution and interaction of large scale structures and to determine their convective velocity, employing a novel spatial correlation technique, which includes a "translating template" that convects downstream with the structure being tracked. Preliminary progress towards the development of a MHz rate Planar Doppler Velocimetry diagnostic is also included.