Glare Spot Phase Doppler Anemometry
Hespel , Camille
Ren , Kuan Fang
Gréhan , Gérard
Onofri , Fabrice
- Publisher: HAL CCSD
[ SPI.FLUID ] Engineering Sciences [physics]/Reactive fluid environment | particle imaging | Phase doppler Anemometry | Dual-Burst PDA | Glare points | refractive index
International audience; The Phase Doppler anemometry has been developed to measure simultaneously the velocity and the size of droplets. The measurement of the refractive index is also necessary since it depends on the temperature and the composition of the particle and its measurement permits both to increase the quality of the diameter measurement and to obtain information on the temperature and/or the composition of the droplets. In this paper, we introduce a Glare Spot Phase Doppler Anemometry which uses two large beams. In this case, the images of the particle formed by the reflected and refracted light, known as glare spots, are separated in space. When a particle passes in the probe volume, the two parts in a signal obtained by a detector in forward direction are then separated in time. If two detectors are used the phase differences between two signals, the distance and the intensity ratio of reflected and refracted parts can be obtained and they provide rich information about the particle diameter and its refractive index, as well as its velocity. This paper is devoted to the numerical study of such a configuration with two theoretical models: geometrical optics and rigorous electromagnetism solution.