Development and applications of two and three component particle image velocimetry techniques for simultaneous measurement in multi-phase flows and automative fuel sprays

Abstract

The introduction of a new imaging approach for simultaneous multi-phase and multi-constituent velocity measurements is the main focus of this research. The proposed approach is based on the use of a single off-the-shelf colour camera which will enable simultaneous imaging of phases/constituents which are colourtagged using fluorescent droplets and multi-wavelength illumination. Highly efficient florescent tracers used to seed the constituents are presented and their visibility in full field imaging experiments is evaluated. A commonly found problem in experimental systems using laser illumination, known as flare, is discussed and the application of the developed fluorescent tracers for its reduction is presented. A strong focus of the imaging approach proposed is its flexibility and simplicity allowing its extension to stereoscopic imaging to obtain simultaneous multi-phase/constituent 3-component measurements with the addition of a second imaging camera. Proof of principle experiments with spatially separated and well mixed flows are presented for which successful phase discrimination is obtained and the uncertainty of the measurements is estimated. The imaging system developed is applied for simultaneous air and fuel velocimetry measurements in a Gasoline Direct Injection spray for which a more detailed understating of the interaction mechanisms is required to generate improved designs. The modified imaging system and experimental setup are presented and previously unavailable simultaneous air/fuel 2 and 3-component velocity fields are presented and analysed