Real-time background oriented schlieren with self-illuminated speckle background

Background oriented schlieren (BOS) is a widely used technique that provides density gradient information in flow fields of interest. Raw BOS image data provide little, if any, visual indication of the density gradients in the flow. The acquired image data must be processed off-line after the test is completed, providing no indication of the quality of the BOS setup nor any feedback on the operational success of the test. The use of graphical processing units (GPUs) enables real-time acquisition, processing and display of BOS image data. In addition to real-time BOS processing, self-illuminated speckle backgrounds are implemented by incorporating a 4 K monitor into the BOS system. The combination of the real-time processing and a computer controlled/generated background speckle pattern enables self-optimization of the BOS system both prior and during testing.