Abstract
RainbowPIV is a recent imaging technology, proposed for time-resolved 3D-3C fluid velocity measurement using a single RGB camera. It dramatically simplifies hardware setup and calibration procedures as compared to alternative 3D-3C measurement approaches. RainbowPIV combines optical design and tailored reconstruction algorithms, and earlier preliminary studies have demonstrated its ability to extract physically constrained fluid vector fields. This article addresses the issue of limited axial resolution, the major drawback of the original RainbowPIV system. We validate the new system with a direct, quantitative comparison with four-camera Tomo-PIV on experimental data. The reconstructed flow vectors of the two approaches exhibit a high degree of consistency, with the RainbowPIV results explicitly guaranteeing physical properties, such as divergence free velocity fields for incompressible fluid flows.
Highlights
IntroductionDivergence-free flow fields for incompressible fluid flow. butions and velocity vector fields
Octagonal tank pt Blazed Grating 2 z us cri x Camera 4Collimated white light beam with DOE divergence-free flow fields for incompressible fluid flow.butions and velocity vector fields.Many single-camera methods suffer from a limited depth-to-width ratio, i.e.they can image only shallow volumes
The depth-of-field of the utilized hybrid refractive/diffractive lens is not affected by the aperture size, RainbowPIV can make use of the largest available aperture for maximum light efficiency, while still maintaining an extended depth-of-field
Summary
Divergence-free flow fields for incompressible fluid flow. butions and velocity vector fields. In principle the volume depth in RainbowPIV can be tuned by a) changing the thickness of the rainbow, and b) adjusting the design of the all-focus camera optics This was demonstrated in (Xiong, Fu, Idoughi & Heidrich 2018), which proposed a reconfigurable RainbowPIV system with an adjustable rainbow generation engine and a varifocal optical design, extending the depth range to (15-50 mm) while the lateral resolution is unaffected. This corresponds to a depth-to-width ratio of 0.3 - 1.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
