This thesis presents the result of a numerical investigation on the airflow characteristics and particle traj ectories inside a small form factor hard disk drive (HDD) enclosure. A simple model and a geometrically exact model of the HDD enclosure are meshed using unstructured tetrahedral elements. Using a commercial flow-solver, the incompressible Navier-Stokes Equations are solved for the two computational domains. The superior results, in term of resolution and accuracy extracted from the detailed model are compared to the simpler model. Using the computed results, insight on the airflow characteristics in the vicinity of the slider are obtained. The effect of a geometrical true arm model on the global flow field is also addressed for typical disk operation conditions. The computed airflow patterns are then used to predict particle trajectories in the vicinity of head/disk interface (HDI), the knowledge of which has relevance for tribological aspects connected with the HDI region. The effects of gravity and thermal gradients on the airflow characteristics within the HDD enclosure are also considered. MASTER OF ENGINEERING (MAE)