DEVELOPMENT OF HYBRID CROSS-CORRELATION AND OPTICAL FLOW METHOD FOR BACKGROUND ORIENTED SCHLIEREN

Abstract
Flow visualization is one of the most active fields of research in fluid dynamics. The BOS technique is a modern measurement technique aimed at obtaining quantitative data based on variations of refractive index in optically transparent fluids. Flow parameters can be measured with a simple experiment configuration with the help of this technique. This project aims to develop a hybrid algorithm combining cross-correlation with an optical flow algorithm that lends itself to an efficient algorithm that extracts the data accurately. A test setup was built for image acquisition for testing of the algorithm. Chronos 2.1 high-speed camera and iPhone 11 mobile phone were used to obtain image data from experiments conducted with a thermal plume from a candle as a unit test subject and an under-expanded jet from a nozzle as the main test subject. The project successfully demonstrated the efficacy of the hybrid cross-correlation and optical flow algorithm in the context of BOS. By integrating these techniques, the project introduced a novel approach to quantitative flow measurement, showcasing its accuracy and reliability in obtaining precise measurements.
Description
Flow visualization is one of the most active fields of research in fluid dynamics. The BOS technique is a modern measurement technique aimed at obtaining quantitative data based on variations of refractive index in optically transparent fluids.
Keywords
Cross-Correlation, Flow Visualization, Optical Flow, Speckle Pattern
Citation