To understand the roles that wear particles play in disk crashes, analytical and numerical approaches have been used to study three dimensional fluid flow and wear particle transport and deposition in computer disk drives. The study shows that wear particles are flying very close to the disk surface. They can deposit on the disk surface and cause damage to disk drives. Cooling air flow through the disk hub of corotating disks has been found to play important roles in removing wear particles from disk drives. Parametric study has shown that the optimum cooling air flow rate is 12 slpm for 8″ disk with the Reynolds number of 150,000.