Erosion is the process by which material is removed from a wall surface due to micromechanical deformation or cracking of the wall’s surface. In fluid-carrying equipment (such as gas and water turbines, pumps, heat exchangers, and so on), surface erosion is caused in part by the impact on equipment walls by solid particles entrained within a fluid flow. Eventually, wall erosion leads to equipment degradation, decreasing the performance, and reduced service life.

A wall material's resistance to erosion depends on its ability to deform under impact, among other factors listed below. With brittle materials, erosion occurs as a result of cracking and chipping away of microsized pieces of wall material, whereas with ductile materials, erosion occurs through a series of repeated micro-plastic deformations. For such materials, the highest rate of erosion usually occurs at impact angles ranging from 20° to 30° [26].

The other parameters that govern the erosion mechanism are:

Experimental erosion data found in the literature are often subject to large uncertainties. Erosion rates reported by different authors can vary greatly (even by some orders of magnitude for the same material [26], [27]).

Note that erosion rates computed by the erosion models in Ansys Fluent are only a qualitative guide to erosion, unless precise values for the model constants are known.