New CFD-based method for erosion prediction in control valves

Control valves often experience erosion produced by the impacts of solid particles within the flow. This is a very serious concern of engineers, as it causes downtime, loss of income, and high repair costs. Field and lab erosion testing are extremely onerous both economically and technically and, for this reason, the use of CFD techniques for erosion prediction is gaining ground in recent years. The standard practice involves the usage of two-phase CFD models which follow the trajectories of all solid particles within the flow. However, the huge computational burden of these models even for simple flows prevents, or even preclude, their application to complex flows of engineering interest such as valve flows. In this paper an innovative approach for erosion prediction is proposed. Its strength compared to the traditional practice resides in the numerical efficiency, arising from the usage of a different CFD two-phase method in which the detailed analysis of the fluid dynamics characteristics of the solid particles is restricted to the vicinity of the surfaces most vulnerable to erosion. This feature reduces considerably the computational burden of the erosion predictions in case of simple flows and, most important, makes it feasible to perform these estimations also in case of complex geometries such as control valves. In this paper, we discuss about the application of the method to sketched model of a Needle and Seat valve after its validation in abrasive jet benchmark tests.