20.500.12556/RUL-117662 Cavitation bubble interaction with a rigid spherical particle on a microscale Cavitation bubble collapse close to a submerged sphere on a microscale is investigated numerically using a finite volume method in order to determine the likelihood of previously suspected mechanical effects to cause bacterial cell damage, such as impact of a high speed water jet, propagation of bubble emitted shock waves, shear loads, and thermal loads. A grid convergence study and validation of the employed axisymmetric numerical model against the Gilmore’s equation is performed for a case of a single microbubble collapse due to a sudden ambient pressure increase. Numerical simulations of bubble-sphere interaction corresponding to different values of nondimensional bubble-sphere standoff distance δ and their size ratio ε are carried out. The obtained results show vastly different bubble collapse dynamics across the considered parameter space, from the development of a fast thin annular jet towards the sphere to an almost spherical bubble collapse. Although some similarities in bubble shape progression to previous studies on larger bubbles exist, it can be noticed that bubble jetting is much less likely to occur on the considered scale due to the cushioning effects of surface tension on the intensity of the collapse. Overall, the results show that the mechanical loads on a spherical particle tend to increase with a sphere-bubble size ratio ε, and decrease with their distance δ. Additionally, the results are discussed with respect to bacteria eradication by hydrodynamic cavitation. Potentially harmful mechanical effects of bubble-sphere interaction on a micro scale are identified, namely the collapse-induced shear loads with peaks of a few megapascals and propagation of bubble emitted shock waves, which could cause spatially highly variable compressive loads with peaks of a few hundred megapascals and gradients of 100 MPa/μm. bubble dynamics cavitation fluid–solid interaction shock wave emission bacteria eradication dinamika mehurčkov kavitacija interakcija fluid – trdnina emisija udarnih valov uničevanje bakterij true false true Angleški jezik Slovenski jezik Članek v reviji 2020-07-20 07:29:24 2020-07-20 07:29:32 2022-08-30 03:59:28 0000-00-00 00:00:00 2020 0 0 13 str. Vol. 69, art. 105252 Dec. 2020 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 532.528(045) 1350-4177 10.1016/j.ultsonch.2020.105252 22788355 RAZ_Zevnik_Jure_2020.pdf RAZ_Zevnik_Jure_2020.pdf 1 BA2F3BF248F3BE29CF13FB666E2BFDA0 7694e482116d0759eaa759f3ef743e46265ee319c55ec04a0c99ac710e5d99d2 3bc4006f-a1b9-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=131548 https://www.sciencedirect.com/science/article/pii/S135041772030626X 0 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=131547 Fakulteta za strojništvo 0 0 0