Local Adaptive Multi-Grid Control Volume Method for the Air Bearing Problem in Hard Disk Drives

Author(s):  
Liping Li ◽  
David B. Bogy

A new local adaptive grid-generating algorithm is developed and integrated with the multi-grid control volume method to simulate the steady state flying condition of air bearing sliders in HDDs (Hard Disk Drives) accurately and efficiently. Two sliders are used to demonstrate the applicability of this method. The results show that this new local adaptive grid-generating method improves substantially the stability and efficiency of the simulation scheme.

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Liping Li ◽  
David B. Bogy

A new, local-adaptive, grid-generating algorithm is developed and integrated with the multigrid control volume method to simulate the steady flying state of the air bearing sliders in hard disk drives (HDDs) accurately and efficiently. Local finer meshes (mesh dimension decreases to half) are created on the nodes of the current finest grids that have pressure gradients or geometry gradients larger than a predefined tolerance after the pressure distribution has been obtained on the initial uniform mesh. In this way, the pressure- or geometry-sensitive regions have higher resolution, leading to more accurate results without inefficiently larger meshes. Two sliders are used to demonstrate the applicability of this method. It is found that this new, local-adaptive, grid-generating method improves the stability and efficiency of the simulation scheme.


Author(s):  
Liping Li ◽  
David B. Bogy

Over the past decade, there has been an increase in the demand of hard disk drives (HDD) used in portable devices. In such applications HDDs are often subjected to mechanical shocks. Hence it is important to study the stability of mobile drives during operational shocks (op-shock) in order to improve their shock performance. Former numerical investigations [1–3] used either detailed structure models and simplified air bearing models or vice versa to understand the HDI response during an opshock event. In 2012, Rai and Bogy [4] proposed a method in which both the HDD components and the air bearing were modeled in detail and were coupled with each other. However, in this model the head actuator assembly (HAA) was assumed to be amounted on a fixed support and hence the flexibility of the base plate and those effects on the HAA were neglected. In this study, we model the HAA as mounted on the base plate to investigate the effects of HDD components on the shock performance of mobile drives.


2007 ◽  
pp. 314-314
Author(s):  
B. J. Shi ◽  
D. W. Shu ◽  
B. Gu ◽  
M. R. Parlapalli ◽  
C. N. Delia ◽  
...  

2006 ◽  
Vol 129 (1) ◽  
pp. 161-170 ◽  
Author(s):  
Jia-Yang Juang ◽  
David B. Bogy ◽  
C. Singh Bhatia

To achieve the areal density goal in hard disk drives of 1Tbit∕in.2 the minimum physical spacing or flying height (FH) between the read/write element and disk must be reduced to ∼2nm. A brief review of several FH adjustment schemes is first presented and discussed. Previous research showed that the actuation efficiency (defined as the ratio of the FH reduction to the stroke) was low due to the significant air bearing coupling. In this paper, an air bearing surface design, Slider B, for a FH control slider with a piezoelectric nanoactuator is proposed to achieve virtually 100% efficiency and to increase dynamics stability by minimizing the nanoscale adhesion forces. A numerical study was conducted to investigate both the static and dynamic performances of the Slider B, such as uniformity of gap FH with near-zero roll over the entire disk, ultrahigh roll stiffness and damping, low nanoscale adhesion forces, uniform FH track-seeking motion, dynamic load/unload, and FH modulation. Slider B was found to exhibit an overall enhancement in performance, stability, and reliability in ultrahigh density magnetic recording.


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