Relationship between material pitting and cavitation field impulsive pressures

Abstract

Material pitting from cavitation has been used on and off as an indicator of the vague concept of ‘cavitation intensity’. Periodically, some researchers suggest the use of pitting tests as a means to provide quantitative measurements of the amplitude of the impulsive pressures in the cavitation field, especially when combined with Tabor׳s formula or with finite element computations with idealized synthetic loads. This paper examines the viability of such a suggested method using fully coupled bubble dynamics and material response, and strongly concludes that the method provides at best a qualitative assessment of the cavitation erosion potential. Peak pressures deduced from pit geometry are significantly lower than the ones actually applied. In addition the correspondence is highly dependent on the way the load is applied and different loading scenarios with the same amplitude of the cavitation impulsive pressure result in different pit aspect ratios.