Observations on Cavitation Damage in a Flowing System

Abstract

Cavitation damage to specimens of stainless steel, carbon steel, aluminum, and plexiglas, placed in a cavitating venturi using water and mercury as test fluids is mostly in the form of irregularly shaped pits which do not change with additional exposure to the cavitating field within the limited durations utilized. The rate of damage is very high initially, decreases for a relatively short period of time, then increases again up to the maximum test durations of 150 hours with water and 270 hours with mercury. Observation of damage effects by several independent techniques, using a variety of specimen materials, with two different fluids under various fluid dynamic conditions, leads to a suggested correlating model in terms of the cavitation bubble density and energy and specimen material strength.

On the mechanisms of cavitation erosion – Coupling high speed videos to damage patterns

“…All the mentioned studies agree that cavitation structures carry a significant amount of potential energy [11] and can, at their collapse, emit pressure waves of magnitude of several MPa [12]. Yet it seems that the macroscopic cavitation cloud collapse itself cannot be a direct cause of erosion as its energy is not enough concentrated.…”

An energy conservative method to predict the erosive aggressiveness of collapsing cavitating structures and cavitating flows from numerical simulations

“…The indicator is derived in two steps. Starting from the potential energy hypothesis by Hammitt (1963) and Vogel and Lauterborn (1988) , the first step involves an energy conservative conversion of locally radiated power into local surface impact power. A modified formulation of the cavitation intensity approach proposed by Leclercq et al (2017) is employed in this step.…”

“…The jet is supposed to cause erosion pit formation if the liquid mass velocity exceeds a critical threshold velocity ( Lush, 1983 ). An important foundation of the shock wave hypothesis on the other hand is the potential energy hypothesis initiated by Hammitt (1963) . According to the later formulation by Vogel and Lauterborn (1988) , it states that the potential energy of the spherical bubble is proportional with its initial volume and the difference between static ambient and vapor pressure.…”

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An energy conservative method to predict the erosive aggressiveness of collapsing cavitating structures and cavitating flows from numerical simulations Schenke, Sören; van Terwisga, Tom J.C.

a b s t r a c tA new technique is proposed in this study to assess the erosive aggressiveness of cavitating flows from numerical flow simulations. The technique is based on the cavitation intensity approach by Leclercq et al (2017), predicting the instantaneous surface impact power of collapsing cavities from the potential energy hypothesis (see Hammitt, 1963;Vogel and Lauterborn, 1988). The cavitation intensity approach by Leclercq et al (2017) is further developed and the amount of accumulated surface energy caused by the near wall collapse of idealized cavity types is verified against analytical predictions.

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Ferroelektretsensor zur Messung der Kavitation in UltraschallreinigungsbädernFerroelectret Sensor for Measurement of Cavitation in Ultrasonic Cleaning Systems

“…Mit Probekörpern wird mittels Differenzwä-gung der durch erosiven Oberflächenangriff bedingte Masseverlust bewertet [3]. Die Geometrie von Erosionsstrukturen wird auf massiven Körpern und auf beschichteten Oberflächen ausgewertet.…”