High-speed 3D imaging of liquid sheet surfaces using the FP-LIF technique

Abstract

Accurate visualization and understanding of liquid breakups and dynamics of liquid jets, sheets, blobs and ligaments is important for a wide range of spray applications. Here, temporally resolved 3D measurements are necessary to obtain the complete characterization these processes. The currently available 3D imaging techniques are usually based on time-averaged data and do not have the capability of 3D temporally resolving fast liquid breakup phenomena. We have developed a novel technique called Fringe Projection -Laser Induced Fluorescence, FP-LIF, with the possibility of generating snapshot 3D surface reconstructions of irregular liquid structures, such as liquid sheets, ligaments, blobs and other large liquid bodies. The advantage of this technique is that only a single camera is used for generating 3D data. In this article we push the technique one step forward by using a Photron SA-Z high-speed camera to obtain 3D reconstructions of a hollow cone liquid sheet structure at 20 000 frames per second. This liquid sheet is generated from a pressure swirl atomizer. Such new type of data, presented here, are particularly relevant for the validation and improvement of computational spray models and for acquiring detailed insight on the conical sheet development and breakup.