Open AccessCavities "Pit Number" and micro-jets impingements
Author(s) -
Gil Bazanini,
Nicodemus Neto da Costa Lima,
José Divo Bressan
Publication year - 2018
Publication title -
semina. ciências exatas e tecnológicas
Language(s) - English
Resource type - Journals
eISSN - 1679-0375
pISSN - 1676-5451
DOI - 10.5433/1679-0375.2018v39n2p81
Subject(s) - cavitation , jet (fluid) , materials science , mechanics , flow (mathematics) , erosion , solid surface , conic section , geometry , composite material , physics , geology , mathematics , paleontology , chemical physics
Cavitation pits and erosion were obtained using the rotating disk device, where a steel disk with cavitation inducers and specimens fixed on it rotates inside a water chamber to provide the cavitating flow. These pits were observed with the aid of a scanning electronic microscopy. Micro-jets resulting from cavity collapse cause damages to solid surfaces. Because they are caused by the micro-jets, these pits are approximate circular. The exponent named pit number was calculated using the pit counting, that is the number of pits by area and by time unit. The influence of flow velocity was also analyzed here, and how greater is the flow velocity, how greater is the pit counting calculated. It was also calculated the distance from the collapsing cavity to the wall, considering a conic micro-jet.