Abstract
In this paper, a numerical method to assess the risk of cavitation erosion is proposed, which can be applied to incompressible simulation approaches. The method is based on the energy description of cavitation erosion, which considers an energy transfer between the collapsing cavities and the eroded surface. The proposed framework provides two improvements compared with other published methods. First, it is based on the kinetic energy in the surrounding liquid during the collapse instead of the potential energy of collapsing cavities, which avoids the uncertainty regarding the calculation of the collapse driving pressure in the potential energy equation. Secondly, the approach considers both micro-jets and shock-waves as the mechanisms for cavitation erosion, while previous methods have taken into account only one of these erosion mechanisms. For validation, the proposed method is applied to the cavitating axisymmetric nozzle flow of Franc et al. (2011), and the predicted risk of cavitation erosion is compared with the experimental erosion pattern. This comparison shows that the areas predicted with high erosion risk agree qualitatively well with the experimental erosion pattern. Furthermore, as the current method can be used to study the relationship between the cavity dynamics and the risk of cavitation erosion, the hydrodynamic mechanism responsible for the high risk of cavitation erosion at the inception region of the sheet cavity is investigated in detail. It is shown for the first time that the risk of cavitation erosion in this region is closely tied to the separation of the flow entering the nozzle.
Highlights
Hydrodynamic cavitation is unavoidable in high-performance hy draulic machineries, such as propellers, water turbines, pumps, and diesel injectors
Indicator of cavitation erosion risk Based on the energy approach, the kinetic energy in the surrounding liquid of collapsing cavities is transferred to the nearby material by shock-wave or micro-jet mechanisms
This paper presents a new method to assess the risk of cavitation erosion using incompressible simulations of cavitating flows
Summary
Hydrodynamic cavitation is unavoidable in high-performance hy draulic machineries, such as propellers, water turbines, pumps, and diesel injectors. The cavitation erosion risk is assessed by applying experimental methods on the prototype of a newly designed machine These experimental methods include visual assessment of collapsing cavities using high-speed videos [1] complemented by paint test and/or acoustic measurement [2,3,4]. Using the energy description of cavitation erosion, a few methods have been proposed [24,25] and applied [26,27,28] in the literature All of these methods, possess the uncertainty regarding the defini tion of the collapse driving pressure, which is noted by Schenke et al [25]. The results are presented including a detailed discussion on the cavitation development and the hydrodynamic mechanisms leading to erosion in this flow as well as the comparison between the predicted risk of cavitation erosion using the developed method and the experimental erosion pattern
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
