While sonoluminescence is a well known phenomenon in acoustic cavitation (Gaitan et al. 1992), luminescence induced in hydrodynamic cavitation have only been addressed at the macro-scale by Farhat et al. (2010). In this experimental work, hydrodynamic cavitation of water is studied in a micro-channel. The nucleation, growth and collapse of microbubbles in the flow is achieved through a micro-step thanks to a strong pressure change. It is found that such flow can induce an emission of a low light signal (~ 200-1500 photons/s). To study the luminescence and to characterize the intensity of cavitation that is directly correlated to this light emission, an experimental set-up was built with an optical detection system, efficiently isolated from any external light sources (noise ~ 10 photons/s). The influence of the experimental system and data analysis on the quantitative data treatment is discussed. The influence of pressure difference is investigated. As well, the effect of dissolved gas concentration (O2, Ar, Xe) into deionized water on luminescence intensity is discussed in relation to existing theory (Flannigan & Suslick 2005).

References:

Gaitan et al. "Sonoluminescence and bubble dynamics for a single, stable, cavitation bubble". The Journal of the Acoustical Society of America. 91 (6): 3166–3183 1992.

Farhat et al. "Luminescence from hydrodynamic cavitation". Proc. Royal Society A, 2010.

Flannigan & Suslick, "Plasma formation and temperature measurement during single-bubble cavitation". Nature, 434, 52–55 2005.