No abstract

The primary focus of this thesis is on the developments of image-based flow diagnostics for supersonic jet flow and noise control. Three different in-house techniques are presented: (1) 3D shock wave reconstruction technique based on schlieren imaging and visual hull concepts, (2) schlieren image velocimetry based on the optical flow algorithm (SIVOF), and (3) a data-driven approach to identify and characterize intermittent jet screech based on proper orthogonal decomposition (POD) of time-resolved schlieren images. The secondary focus is to provide experimental data and improve understanding on problems associated with the supersonic jet. To this end, the in-house techniques are applied in conjunction with conventional experimental techniques to Mach number 1.45 supersonic cold jets produced from convergent-divergent circular nozzles. In order to achieve flow and noise control,