In this paper, the effect of vortex finder shape on the performance and flow field of the new design cyclones is numerically investigated using CFD techniques. Nine different geometries of vortex finder are studied in three categories each with three geometries. In the first category, the effect of vortex finder flattening is investigated. In the second category, vortex finders with three different cross section geometries circular, square and triangular are investigated. Finally, in the third category, circular vortex finders with three different diameters are modeled. The new design cyclone is based on the idea of improving cyclone collection efficiency and pressure drop by increasing the vortex length. The Eulerian-Lagrangian computational procedure is used to predict particles tracking in the cyclones. The velocity fluctuations are simulated using the Discrete Random Walk (DRW). The results show that in the flat category, vortex finder without flattening (circular cross section) possess the maximum efficiency and the lowest pressure drop and with flattening, the cyclone efficiency dramatically decreases while pressure drop remarkably increases. Among the vortex finder with different cross section, maximum efficiency is associated to the circular vortex finder while the lowest pressure drop is assigned to the triangle one.
