Interaction of a cavitation bubble with a polymeric coating–scaling fluid and material dynamics. (March 2019)

• Record Type: Journal Article
• Authors: Chahine, Georges L.; Gnanaskandan, Aswin; Mansouri, Amir; Hsiao, Chao-Tsung; Content, Romain
• Is Part Of: International journal of multiphase flow. Volume 112(2019)
• Page Start: 155
• Page End: 169
• Publication Date: 2019-03
• Subjects: Multiphase flow -- Periodicals; Écoulement polyphasique -- Périodiques; Multiphase flow; Periodicals; 620.1064
• DOI: 10.1016/j.ijmultiphaseflow.2018.12.014
• Languages: English
• ISSNs: 0301-9322

Abstract

Highlights: This paper addresses the interaction between a cavitation bubble and a polymeric coating. Spark-generated bubbles are used to visualize the bubbles. The polymeric coating is represented in the scaled experiment by Agar. Parallel numerical simulations model the fluid structure interaction. The simulations show that the scaled tests actually provide an accurate picture of the interaction between a microscopic bubble in a cavitating jet and Polyurea. The paper proposes a procedure to conduct accurate scaling. Abstract: Cavitation bubble dynamics and interaction with a polymeric coating material can be scaled in space and time using spark-generated bubbles near an appropriate soft material and can be simulated using fluid-structure interaction (FSI) modelling. In this paper, cavitation bubble dynamics in a high-pressure cavitating jet eroding a Polyurea layer on a rigid substrate is simulated using spark-generated bubbles operating at reduced pressures near an Agar layer of a properly selected concentration. Geometric scaling is based on the ratio of bubble maximum radii in the two configurations, and fluid dynamics scaling follows the Rayleigh scaling, i.e. lengths are normalized by the bubble maximum radius and times by the Rayleigh time. Scaling of the materials properties is achieved by equating the ratio of the materials mechanical properties (Young's and shear moduli) to the ratio of the local ambient pressures collapsing the bubble. Full FSI numerical simulations conducted at different scales with the two materials indicate the validity of the scaling.