Borescopic Spatio-temporal Measurements of Droplet Size and Velocity with kHz Resolution

Recently our group successfully developed a Digital Particle Image Velocimetry with a sampling frequency as high as 10,000 fps capable of resolving poly-dispersed multi-phase flows simultaneously for all phases present in the flow field. We were successful in developing very sophisticated image processing algorithms and velocity evaluation methodologies that deliver velocity and size measurements with accuracy better than 0.1%. We propose to capitalize on our previous success and develop a next generation Time-Resolved DPIV system with the capability to resolve quantitatively, both velocity and size of poly-dispersed multi-phase flows and in particular, sprays in a cross-flow, with 10 kHz sampling frequency. We propose to develop new methods to improve the accuracy of the velocity evaluation and new methods to provide quantitative droplet size measurements. Most importantly, we will design, built, and test a novel endoscopic imaging module based on gradient index rod lenses, that will be integrated with the DPIV system and will allow measurements in inaccessible or hostile environments. The proposed system will deliver droplet size measurements using exactly the same hardware as a DPIV velocity measurement system therefore alleviating the need for complex inteferometric setups, reducing the number of hardware components and cost and increasing ease of operation.