Revealing the origins of vortex cavitation in a Venturi tube by high speed X-ray imaging
Hitoshi SOYAMA, Xiaoyu Liang, Wataru Yashiro, Kentaro Kajiwara, E. M. Asimakopoulou, Valerio Bellucci, Šarlota Birnšteinová, Gabriele Giovanetti, Chan Kim, Henry Kirkwood, Jayanath Koliyadu, Romain Letrun, Yuhe Zhang, Jozef Uličný, Richard Bean, Adrian P. Mancuso⋈, Pablo Villanueva‐Perez, Tokushi Sato, Patrik Vagovič, Daniel Eakins, Alexander M. Korsunsky
Abstract
Hydrodynamic cavitation is useful in many processing applications, for example, in chemical reactors, water treatment and biochemical engineering. An important type of hydrodynamic cavitation that occurs in a Venturi tube is vortex cavitation known to cause luminescence whose intensity is closely related to the size and number of cavitation events. However, the mechanistic origins of bubbles constituting vortex cavitation remains unclear, although it has been concluded that the pressure fields generated by the cavitation collapse strongly depends on the bubble geometry. The common view is that vortex cavitation consists of numerous small spherical bubbles. In the present paper, aspects of vortex cavitation arising in a Venturi tube were visualized using high-speed X-ray imaging at SPring-8 and European XFEL. It was discovered that vortex cavitation in a Venturi tube consisted of angulated rather than spherical bubbles. The tangential velocity of the surface of vortex cavitation was assessed considering the Rankine vortex model.