A New Model for the Equation Describing the Cavitation Mean Depth Erosion Rate Curve

Abstract

Paper present a new relation describing the curve MDER(t) which mediates the experimentally obtained values of the mean depth erosion rates. These curves are used to characterize the cavitation erosion behavioor of materials tested in the Cavitation Laboratory of Timisoara Polytechnic University. Practically the new relation is an improvement of the analytical model established in 2004 by Bordeasu and coworkers, by introducing a supplementary element, which take into consideration the shape of the zone in where the cavitation erosion rate became stable and has linear variation. These addition allow increasing the approximation of the experimental values and also putting into evidence the tiny differences between different materials (various types of stainless steels, highly alloyed bronzes etc.) which till now were considered with similar resistance. Thus, the supplementary term allow a better differentiation resulting from the chemical composition, the structure and the mechanical properties.

New Results Regarding Cavitation Behavior of Polymers Modified with Anorganic Substances Coated on Bronze Surfaces

“…The use of curves and specific parameters, as usually done for resistance evaluation to cavitation erosion, is not possible due to short testing duration. The duration of cavitation testing in our laborator y, for making the specific curves and determinating the values of characteristic parameters using the relations established in laboratory [22], is minimum 165 min.…”

Influence of aging heat treatment at 180 °C on cavitation erosion for aluminum alloy type 5083 in cold rolled state

“…The values of the cumulative average erosion depth and the average penetration rate characterize the evolution of the erosion in the depth and area of the surface structure exposed to the cavity. For the analysis of the behavior of the surfaces modified by the different durations of maintaining at the temperature of 180 0 C the heat treatment of artificial aging, at the demands of the vibrating cavity, the values obtained from the measurements were mediated by analytical curves whose shapes are established in the Cavitation Erosion Research Laboratory [17], [20], as follows:…”

Cavitation Resistance of Elastomeric Coatings Deposited by Different Methods

“…This phenomenon that consists in the progressive loss of material from a solid surface, affects the runner blades and adjacent areas of the runner [1]. Cavitation is caused by continuous collapse of numerous bubbles due to localized pressure changes during high velocity flow [1,4]. If the pressure suddenly falls below the vapors pressure, the tensile stress imposed on the liquid generates cavities, because of the numerous small solid and gaseous cavitation nuclei generally present in a real liquid.…”

“…The cavities collapse violently when they reach a point of greater pressure. This collapse is accompanied by the sudden flow of liquid, which originates stress pulses that can cause plastic deformation on solid surfaces [2][3][4].Because the elastomers are a class of soft materials resistant to high loads that can recover their initial shapes after multiple cycles of large deformations, allowing reversible and repeated variations, their functional characteristics have been investigated for a wide range of industrial applications [5][6][7][8]. Depending on the type of system in which elastomeric materials are used, they usually manifest good resistance to tensile stresses and good wear behavior [9][10][11][12][13][14].…”

“…The cavities collapse violently when they reach a point of greater pressure. This collapse is accompanied by the sudden flow of liquid, which originates stress pulses that can cause plastic deformation on solid surfaces [2][3][4].…”