Numerical study of the fluid flow and particle dynamics is presented by numerical techniques to characterize the performance of new cyclone separators. The design of this cyclone is based on the idea of improving cyclone performance by increasing the vortex length. This cyclone differs from a conventional cyclone with the separation space. Instead of conical part, the separation space of this cyclone consists of an outer cylinder and a vortex limiter. The Reynolds averaged Navier-Stokes equations with Reynolds stress turbulence model (RSM) are solved by use of the finite volume method based on the SIMPLE pressure correction algorithm in the computational domain. 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). In the results the dependency of collection efficiency and pressure drop on different geometrical parameters is investigated. Contours of velocity, pressure and turbulent kinetic energy within these cyclones are shown. Tangential velocity profiles and velocity vectors in different sections are investigated. (C) 2016 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.