Novel Eulerian formulation for dilute gas-particle flows with an obstruction

A novel Eulerian formulation for dilute gas-particle flows with an obstruct ion is developed by laking into consideration explicitly incident and refle cted particles. Particles in a control volume are separated into two famili es, incident and reflected, each of which is assumed to move with approxima tely the same velocity. The drag force over a control volume is split into two components, one for the incident and one for the reflected particles, e ach of which can be physically consistently calculated using a standard for mula. The particulate phase flow can be described equivalently by the compo site family, which consists of incident and reflected particles. The partic ulate flow of incident particles is first evaluated by applying an outflow boundary condition at windward obstruction surfaces, and then the composite particulate flow is computed using the information of the incident particl e solution. The novel formulation is implemented in the commercial computat ion fluid dynamics code, FLUENT, via User Defined Subroutines. The predicti on of dilute gas-particle flows past a 45 degrees ramp and a cylinder with afterbody employing our novel Eulerian formulation shows excellent agreemen t with the results predicted by the Lagrangian approach. The detailed analy sis shows that the key mechanism involved in our novel Eulerian formulation is the correctly treated drag force oner each control volume. Our novel Eu lerian formulation can provide a useful approach for studying erosion and d eposition in coal-fired boilers.