Development of a Mechanistic 3D Solid Particles Erosion Model

Summary Solid particle erosion has a significant impact on the operational reliability and cost of tools and equipment. Optimized designs can extend the erosion wear life by several orders of magnitude compared with suboptimal ones. Traditionally, new product designs were qualified through physical erosion tests under simulated conditions. However, the large-scale equipment required for these tests is costly, and the tests are time-consuming and can also raise safety concerns for gas applications. Recently, computational fluid dynamics (CFD) has started to replace physical tests and driving design optimization; however, it requires a generic erosion model for a range of industrially used materials. A generalized erosion model, incorporating only three material-dependent constants, has been derived based on the cutting and deformation mechanisms induced by 3D particles impact. The first constant is related to the material’s hardness and can be approximated from the material’s properties. The second constant pertains to the material’s toughness, reflecting the energy absorbed through elastic-plastic deformation. The third constant is associated with the continuous deformation wear factor. The resultant erosion model equations explain the experimentally observed phenomenon that the erosion exponent exceeds 2.0, which is attributed to the cutting by a near-spherical 3D particle. The exponent is 2.5 below the transitional impact angle, reducing to 2.0 at the higher impact angles. Additionally, the model provides an equation for the erosion impact angle function that differs from those in existing models, especially at low impact angles, where experimental measurements are challenging. It is also derived that the cutting mechanism transition angle is not constant, as commonly assumed, but decreases as the impact velocity increases. The proposed model is based on the fundamental laws of energy conservation and is simplified, making it suitable for implementation in CFD software. The physics-based nature of the equations also enables the estimation of coefficients for new materials that have not been erosion tested, based solely on their available mechanical properties, such as hardness, toughness, and Young’s modulus. Comprehensive validation against experimental data for nine metallic alloy materials confirmed the model’s accuracy. The study also provides a table of erosion model coefficients for common engineering metal alloys that can be used in the model implementation.