Reduced order models for a high speed jet with time-resolved PIV

In the current investigation, we examine a turbulent, compressible jet flow field in the high subsonic range (Mach 0.85). Experiments take place in the fully anechoic jet facility at Syracuse University, where the flow field is probed in order to measure near-field hydrodynamic pressure, far-field acoustic sound, and near-field velocity. High resolution 10 kHz time-resolved particle image velocimetry (TRPIV) is implemented to gain better insight into the structures formed in the region of the collapse of the potential core of the jet. By exploring these structures in conjunction with the near and far-field pressure, low-dimensional modeling techniques are implemented. With such techniques as proper orthogonal decomposition (POD) and observable inferred decomposition (OID), we seek to gain a better understanding of how jet noise created in the near-field propagates downstream, and how control can be implemented accordingly using such approaches. It has been found that through low-dimensional modeling techniques, "loud" modes in the flow have been identified, which will be utilized through a closed-loop control methodology.