High-speed Schlieren Imaging using Event-based Vision Cameras

Abstract

This study investigates the potentials of the recently introduced event-based vision (EBV) technology in the context of schlieren visualization. Unlike the ubiquitous framing cameras, EBV sensors record only contrast changes within the observed scene producing an asynchronous stream of contrast change "events" consisting of spatial coordinates and time-stamp of the event. With a response latency of order 100 µs, dynamic scenery can be acquired at the equivalent of 10,000 frames/s. In flow diagnostics the technology has already found increased interest for particle tracking velocimetry (PTV) or background oriented schlieren (BOS). In the present contribution the authors apply EBV for high-speed schlieren visualization to assess its potential in comparison with conventional frame based-imaging. Visualizations of the unsteady flow within a transonic compressor cascade are presented. Spectra extracted from the raw event data agree with those obtained with conventional high-speed schlieren imaging.