New method for predicting the incipient cavitation index by means of single-phase computational fluid dynamics model

Abstract

Due to its serious consequences, cavitation in pipeline systems is one of the main concerns of engineers. In this context, the incipient cavitation index defined in many international standards such as those from International Society of Automation and International Electrotechnical Commission is a very important parameter as it accounts for the onset of cavitation. However, the standards define only the experimental determination of the incipient cavitation index, which is furthermore difficult to perform due to the considerable technical and economical burden of the experimental tests, above all in case of large-size systems. In this work, we propose a new method for predicting the incipient cavitation index by means of computational fluid dynamics, avoiding the need of making any experiment. The method is based on the generalized pressure criterion and requires only one Reynolds-averaged Navier–Stokes simulation of single-phase incompressible flow to provide estimates of the incipient cavitation index. The method is applied to predict the incipient cavitation index of multi-hole orifices with different geometrical characteristics, in terms of equivalent diameter ratio (0.40–0.70), relative thickness (0.73, 1.00), and number (13–52) and disposition of the holes. The experimental data revealed the reliability of the method. Its applicability was also confirmed for more complex geometries, and an application example regarding a control valve is briefly illustrated at the end of this article.