The Box-Behnken design of mathematical model for cyclone separator was developed for the interactions of particle size, feed load, and pressure drop in the cyclone separator to determine the collection efficiency of sand particles. The collection efficiency of 90% and above was obtained by operating the cyclone separator in pressure drop range of 197-490 Pa for diameter of sand particles in the range of 200-800 mu m. The axial and tangential velocities were evaluated using Barth model for the cyclone separator studies. The studies were used to determine the contour regions of pressure fields and various velocity fields using computational fluid dynamics software Fluent for the purpose of flow analysis in the cyclone separator. The static pressure reduces from the wall to the center and negative pressure zone exists at central region due to presence of vortex zone.