| This dissertation focuses on the development of a general purpose slider air bearing simulation program to be used as a tool for designing air bearings in modern hard disk drives. The computer code, called the CML Air Bearing Design Program, implements a multi grid control volume method to solve the generalized Reynolds equation. It can simulate all the main air bearing surface features such as multiple etch depth, shaped rails, and arbitrary wall profile. A mass flow rate averaging method is incorporated to deal with clearance discontinuities.; It is found that aligning the grid lines with rail boundaries and the taper location can improve the accuracy and consistency of the solution. A adaptive grid method based on the pressure gradient field is also implemented which greatly facilitates grid generation. The implementation of a full approximation storage and full multi grid method dramatically improves the solver efficiency.; Under high speed, low spacing conditions, the numerical solution may become unstable if the central difference method is used for the convective term in the Reynolds equation. Several alternatives are compared and it is found that the hybrid scheme is superior to all other schemes for slider air bearing applications.; Several sub-25 nm, "negative pressure" slider designs are presented. The designs all have flat fly height profiles across the disk radius and low take-off speeds. It is found that the wall angle resulting from the etching process can alter the air bearing fly height significantly. It is important to include the wall angle effect in the simulation. |
