ANALYSIS OF EROSIVE CAVITATION BY HIGH SPEED VIDEO RECORDS

Övrigt konferensbidrag, 2011

The paper, being a continuation of a paper presented at AMT09, deals with detection of erosive cavitation and analysis of hydrodynamic mechanisms of scales possible to relate to engineering design selections. With the present analysis of cavitation events the two papers provide a significant update and supplement to parts of the EROCAV observation handbook. The main contribution in this paper is the extension of the decomposition of the hydrodynamics of erosion, which now covers the main mechanisms down to medium small scales, including generation of vortices at the end of an asymmetric collapse of a cavity, the internal flow in a cavity and mechanisms for generation of cloud cavitation. The decomposition introduced unfolds the collapse and rebound processes into sub processes related to detection and control of erosion. These processes are typically related to the global flow and observations improve the assessment and links to design considerations. The decomposition and analysis are applicable on data from experiments and advanced numerical simulations. The decompositions relate to selections in model testing, high-speed video recordings and numerical simulations and form a background for advanced prediction and design work.