On numerical modeling of particle–wall impaction in relation to erosion prediction: Eulerian versus Lagrangian method

The modeling of particle–wall impaction in a confined gas-particle flow using both Lagrangian and Eulerian approaches is reported. The Lagrangian method is based on a general computational fluid dynamics (CFD) code, FLUENT (FLUENT-4.3, 1996). In the Eulerian method, based on our previously developed code [J. Eng. Gas Turb. Power 119 (1997) 709], a computational procedure by decomposing one Eulerian solution of particulate phase into two equivalent Lagrangian solutions for incident and reflected particles has been developed. These two approaches are evaluated versus experimental data for particle–wall impaction using spray droplets. Two test cases, a 45° ramp and an isolated single tube, have been studied using the above two approaches to determine the particle behavior and physical properties of impacting and reflected particles near wall surface. Results show that both approaches are successful in predicting the main features of particulate flow near wall, however, the Eulerian approach is much less expensive than the Lagrangian approach in obtaining the flow solution of impacting particles. The particulate flow predictions using both approaches have been applied for predicting tube erosions that are compared with reported data. Good agreement between predictions using the two approaches and between the predicted and measured erosion results are observed.