Elastohydrodynamic Analysis of Head to Flexible Disk Interface Phenomena

1981 ◽  
Vol 48 (4) ◽  
pp. 763-768 ◽  
Author(s):  
J. P. Licari ◽  
F. K. King
Keyword(s):  
Finite Element ◽  
Finite Difference ◽  
Numerical Models ◽  
Disk Interface ◽  
Disk Rotation ◽  
Lubrication Equation ◽  
Interface Phenomena ◽  
Element Approach ◽  
Flexible Disk ◽  
Finite Difference Techniques

The finite-element and finite-difference techniques are used to develop an analytical model which describes the interaction between a magnetic recording head and a flexible disk. The finite-element approach is used to describe disk deformation. Both disk bending stiffness and stiffness effects due to disk rotation are included. The finite-difference scheme is used to solve the Reynold’s or lubrication equation which describes the flow interaction between head and disk. The procedure used to couple the two numerical models into a complete head-to-disk interface simulator is outlined. Accuracy of the simulator is verified experimentally, and results of studies showing the sensitivities of various parameters are given.

scholarly journals Efficiency of High-Order Accurate Difference Schemes for the Korteweg-de Vries Equation

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Kanyuta Poochinapan ◽  
Ben Wongsaijai ◽  
Thongchai Disyadej
Keyword(s):  
Finite Difference ◽  
Fourth Order ◽  
Kdv Equation ◽  
Numerical Models ◽  
Finite Difference Methods ◽  
Von Neumann ◽  
The Kdv Equation ◽  
Von Neumann Analysis ◽  
Numerical Tools ◽  
Finite Difference Techniques

Two numerical models to obtain the solution of the KdV equation are proposed. Numerical tools, compact fourth-order and standard fourth-order finite difference techniques, are applied to the KdV equation. The fundamental conservative properties of the equation are preserved by the finite difference methods. Linear stability analysis of two methods is presented by the Von Neumann analysis. The new methods give second- and fourth-order accuracy in time and space, respectively. The numerical experiments show that the proposed methods improve the accuracy of the solution significantly.

Finite Element Analysis of the Dynamics of Flexible Disk Rotor Systems

1982 ◽  
Author(s):  
J. A. Palladino ◽  
J. N. Rossettos
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
System Matrix ◽  
Element Analysis ◽  
Finite Element Approach ◽  
Rotor Systems ◽  
Rigid Disks ◽  
Blade System ◽  
Element Approach ◽  
Flexible Disk

The trend towards higher speeds and lighter weight rotor designs, particularly in gas turbine applications, has brought about the need to consider the flexibility of the total shaft-disk-blade system in the calculation of system frequencies and whirl modes. It has been traditional to assume that blades and disks are rigid, although recent work has been aimed at evaluating the assumption of rigid disks. These works have used Laplace transform and Liapunov methods and have been limited to simple geometries. This paper describes the development of a special shaft finite element which incorporates analytical solutions for disk dynamics and approximations of blade effects. It is shown that the addition of disk and blade dynamics does not increase the size of system matrix and that this approach can consider multiple disks. Because of the versatility of the finite element approach, complex configurations and boundary conditions can be considered.

Factored-lmplicit Finite Difference Solution of a Non-Newtonian Fluid Lubrication Equation for Three-Dimensional Bearings

1996 ◽  
Vol 118 (4) ◽  
pp. 824-831 ◽  
Author(s):  
J. W. White
Keyword(s):  
Shear Stress ◽  
Finite Difference ◽  
Strain Rate ◽  
Data Storage ◽  
Newtonian Fluid ◽  
Time Interval ◽  
Finite Width ◽  
Disk Interface ◽  
Static And Dynamic Analysis ◽  
Lubrication Equation

A time dependent lubrication equation is developed for a non-Newtonian fluid whose shear stress is expressed in terms of instantaneous strain rate. By expanding the shear stress through a two function Taylor series, the stress/strain-rate relationship is linearized within the time interval (tn ≤ t ≤ tn+1) but accurate to O(Δt2). This produces a linear lubrication equation which is second-order time-accurate. The resulting finite difference form of the lubrication equation is then factored and split into two equations, each of which represents a sequence of one-dimensional systems of tri-diagonal scalar equations. A finite difference code based on this algorithm was written called VISQUSFLO which provides static and dynamic analysis of the head/disk interface of data storage systems. Numerical examples of a shear-thinning fluid are presented for clearances in the range of 25-50 nm for finite width slider bearings.

Non-Destructive 3-D Determination of Interior Stresses

2011 ◽  
Vol 70 ◽  
pp. 476-481 ◽  
Author(s):  
S.J. Lin ◽  
S. Quinn ◽  
B.R. Boyce ◽  
R.E. Rowlands
Keyword(s):  
Finite Element ◽  
Finite Difference ◽  
Stress Analysis ◽  
Thermoelastic Stress ◽  
Experimental Results ◽  
Thermoelastic Stress Analysis ◽  
The Individual ◽  
Non Destructive ◽  
Finite Difference Techniques

Thermoelastic stress analysis and grey-field photoelasticity are combined with the Laplace and Beltrami-Michell equations to non-destructively evaluate the individual internal components of stress in a loaded 3-D aluminium member. Experimental results agree with those predicted numerically by the finite element and finite difference techniques.

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