Use of an upwind finite volume method to solve the air bearing problem of hard disk drives

2000 ◽  
Vol 26 (6) ◽  
pp. 0592-0600 ◽  
Author(s):  
Lin Wu ◽  
D. B. Bogy
Keyword(s):  
Finite Volume Method ◽  
Finite Volume ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Air Bearing ◽  
Disk Drives ◽  
Volume Method

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

2012 ◽  
Author(s):  
Liping Li ◽  
David B. Bogy
Keyword(s):  
Control Volume ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Adaptive Grid ◽  
Air Bearing ◽  
Disk Drives ◽  
Control Volume Method ◽  
Generating Method ◽  
The Stability ◽  
Volume Method

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.

Unstructured Adaptive Triangular Mesh Generation Techniques and Finite Volume Schemes for the Air Bearing Problem in Hard Disk Drives

2000 ◽  
Vol 122 (4) ◽  
pp. 761-770 ◽  
Author(s):  
Lin Wu ◽  
D. B. Bogy
Keyword(s):  
Finite Volume ◽  
Mesh Generation ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Triangular Mesh ◽  
Air Bearing ◽  
Disk Drives ◽  
Algebraic Equations ◽  
Finite Volume Schemes ◽  
Linear Algebraic Equations

Unstructured adaptive triangular mesh generation techniques and vertex based finite volume schemes that suit slider air bearing simulation of hard disk drives are constructed and implemented. Different refinement and adaptation techniques are used to generate several levels of good quality mesh over sliders with complex rail shapes. At each level, either one geometrical or one physical property of the problem is captured. A group of implicit vertex based finite volume schemes is first constructed. The resulting simultaneous linear algebraic equations are solved iteratively by the Gauss-Seidel method. Unconditional stability of the scheme is achieved. In addition, we present a non-nested full approximation storage (FAS) multi-grid algorithm that can significantly speed up the convergence rate of the implicit finite volume schemes. The steady state flying attitude is obtained by a quasi-Newton iteration method. [S0742-4787(00)01804-X]

A Local Adaptive Multigrid Control Volume Method for the Air Bearing Problem in Hard Disk Drives

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Liping Li ◽  
David B. Bogy
Keyword(s):  
Control Volume ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Adaptive Grid ◽  
Uniform Mesh ◽  
Air Bearing ◽  
Disk Drives ◽  
Control Volume Method ◽  
Generating Method ◽  
Volume Method

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.

Air Bearing Slider Simulation and Modeling for Hard Disk Drives with Ultra-Low Flying Heights

2007 ◽  
pp. 314-314
Author(s):  
B. J. Shi ◽  
D. W. Shu ◽  
B. Gu ◽  
M. R. Parlapalli ◽  
C. N. Delia ◽  
...  
Keyword(s):  
Hard Disk Drives ◽  
Hard Disk ◽  
Air Bearing ◽  
Disk Drives ◽  
Simulation And Modeling ◽  
Air Bearing Slider

Design and Dynamics of Flying Height Control Slider With Piezoelectric Nanoactuator in Hard Disk Drives

2006 ◽  
Vol 129 (1) ◽  
pp. 161-170 ◽  
Author(s):  
Jia-Yang Juang ◽  
David B. Bogy ◽  
C. Singh Bhatia
Keyword(s):  
Numerical Study ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Areal Density ◽  
Flying Height ◽  
Air Bearing ◽  
Disk Drives ◽  
Adhesion Forces ◽  
Surface Design ◽  
Ultrahigh Density

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.

A Fast Implicit Algorithm for Time-Dependent Dynamic Simulations of Air Bearing Sliders

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Wei Hua ◽  
Shengkai Yu ◽  
Weidong Zhou ◽  
Kyaw Sett Myo
Keyword(s):  
Finite Volume Method ◽  
Finite Volume ◽  
Triangular Mesh ◽  
Time Dependent ◽  
Air Bearing ◽  
Dynamic Simulations ◽  
Unstructured Triangular Mesh ◽  
Simulation Results ◽  
Time Accuracy ◽  
Volume Method

An unstructured triangular mesh is successfully applied to the static simulations of air bearing sliders due to its flexibility, accuracy and mesh efficiency in capturing various complex rails and recess wall regions of air bearing surface, as well as fast simulation speed. This paper introduces a new implicit algorithm with second order time accuracy for the time-dependent simulations of the slider dynamics and available for the unstructured triangular mesh. The new algorithm is specially developed for the finite volume method. Since the algorithm has second order time accuracy, it provides the flexibility of applying various time steps while guaranteeing the numerical accuracy and convergence. Moreover, the unstructured triangular mesh is highly efficient and fewer nodes are used. Finally, due to the small variation of flying attitude between two neighboring time steps, it is especially efficient for iteration methods which are used in the finite volume method. As a result, the algorithm shows very fast speed in time-dependent dynamic simulations. Simulation studies are conducted on the flying dynamics of a thermal flying-height control slider after external excitations. The simulation results are compared with the simulation results obtained by the rectangular mesh based on the finite element method. It is observed that the simulation results are well correlated. The fast Fourier transform is also employed to analyze the air bearing frequencies. It is indicated that the new algorithm is of high efficiency and importance for time-dependent dynamic simulations.

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