Fluorescent tracer particles have found a number of uses in PIV. A light sheet produces flare when it impinges upon an object within the field of view, preventing particle images from being obtained and hence preventing velocity measurements in that locality. An example is shown in figure 1 where 532nm light is used for excitation and imaging. Whilst in some situations flare may be minimized by careful experiment setup, in some applications flare is difficult to avoid and prevents information from being obtained, e.g. in boundary layer measurements. A further application has been explored where fluorescent tracers are used to optically label one phase or constituent of a flow and thereby enable simultaneous multi-constituent PIV [1-3]. The general application of fluorescent tracers to gas phase flow seeding requires sufficient fluorescence emission from micron sized tracers when imaged over 10s of mm field of view. For multi-constituent and multi-phase flows sufficient chromatic separation is also required between the illumination and the fluorescence and between the fluorescence and any wavelengths used for Mie scattering. 德國LaVision PIV/PLIF粒子成像測速場儀 Imager sCMOS PIV相機(jī)