scholarly journals High Speed Tribology of the Head-Disk Interface by Computer Simulation Final Report CRADA No. TC-297-92-C

2018 ◽  
Author(s):  
J. F. Belak ◽  
W. J. Martin
Keyword(s):  
Computer Simulation ◽  
High Speed ◽  
Final Report ◽  
Head Disk Interface ◽  
Disk Interface

scholarly journals In Situ Measurement of Seeking Speed and Seeking Induced Head-Disk Interface Instability in Hard Disk Drives

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Yu Wang ◽  
Xiongfei Wei ◽  
Yanyang Zi ◽  
Kwok-Leung Tsui
Keyword(s):  
High Speed ◽  
Hard Disk Drives ◽  
Laser Doppler Vibrometer ◽  
Voice Coil Motor ◽  
In Situ Measurement ◽  
Head Disk Interface ◽  
Magnetic Head ◽  
Interface Instability ◽  
Disk Interface

This paper investigated the instability of head-disk interface caused by the voice coil motor (VCM) end crashing the crash stop during the seeking of magnetic head. To make the whole process of that clear, an in situ measurement method based on maximum likelihood estimation and extended Kalman filter for seeking speed at component level was developed first and was then calibrated by a high speed camera. Given a crash between VCM end and crash stop that may be a consequence of the continuous increasing seeking speed, the seeking speed was carefully controlled by using our developed method to find a critical value that may induce vigorous head-disk interface instability. Acoustic emission sensor and laser Doppler vibrometer were used to capture the transient dynamic behaviors of magnetic head when the crash is happening. Damage analysis and mode identification were carried out to reveal the relationship between the damage patterns on disk surface and head dynamics. The results of this study are helpful to optimize the track seeking profile during the HDD operation, as well as the design of components such as head and head arm.

Dynamic Analysis of Sliding Contacts at Head-Disk Interface

2002 ◽  
Author(s):  
T.-J. Chuang ◽  
S. M. Hsu
Keyword(s):  
Data Storage ◽  
High Speed ◽  
Time History ◽  
Disk Drive ◽  
Element Model ◽  
Disk Surface ◽  
Magnetic Data ◽  
Head Disk Interface ◽  
Sliding Contacts ◽  
Disk Interface

As magnetic data storage technology moves towards higher areal data density with higher rotational speeds and lower flying heights, the propensity of severe sliding contacts at the head-disk interface is bound to increase. The tribological performance of the head-disk interface will have significant impact on the durability and service life of the hard disk drive (HDD). A 3D finite element model is constructed to simulate the high speed impact event of a slider on the disk surface. For a given design of the disk with known layer thicknesses and properties, as well as that of the slider with its surface texture, the model predicts contact zone, depth force and duration as well as time-history of energy transfer and its partition, substrate stress and plastic zone for a given impact velocity. The effects of the material properties and layer thicknesses on the performance of the HDD are investigated.

Experimental Study of High-Speed Contact at Head-Disk Interface in a Magnetic Hard Disk

2005 ◽  
Author(s):  
Mingwu Bai ◽  
Stephen M. Hsu
Keyword(s):  
Acoustic Emission ◽  
High Speed ◽  
Hard Disk ◽  
Disk Drive ◽  
Test Method ◽  
Head Disk Interface ◽  
Emission Analysis ◽  
Disk Interface ◽  
Emission Signal ◽  
Carbon Overcoats

Tribological performance of the head-disk interface will have significant impact on the performance and durability of the hard disk drive. A high-speed contact test method has been developed for the purpose of evaluating nanometer-thick lubricant film/carbon overcoats materials on hard-disk surfaces. Four different thickness overcoats were used in high speed contact experiments. High speed contact force was calculated based on the calibration of acoustic emission signal by proposed ball dropping tests. Acoustic emission analysis, frequency spectrum analysis, and surface morphology imaging were used to analyze the deformation and fracture at high speed contacted area. The availability of an experimental technique enables effective screening of different material chemistries and lubricant combinations to improve the level of protection for hard disk technology.

COMPUTER SIMULATION OF FLOW IN CORRUGATED CHANNEL OF PLATE HEAT EXCHANGER

2020 ◽  
pp. 51-58
Author(s):  
Л. А. Кущев ◽  
В. Н. Мелькумов ◽  
Н. Ю. Саввин
Keyword(s):  
Computer Simulation ◽  
Heat Exchanger ◽  
Heat Exchange ◽  
High Speed ◽  
Exchange Process ◽  
Plate Heat Exchanger ◽  
System Stability ◽  
Plate Heat ◽  
Corrugated Channel ◽  
Heat Exchange Process

Постановка задачи. Рассматривается теплообменный процесс, протекающий в модифицированном гофрированном межпластинном канале интенсифицированного пластинчатого теплообменного аппарата с повышенной турбулизацией теплоносителя. Необходимо разработать компьютерную модель движения теплоносителя в диапазоне скоростей 0,1-1,5 м/с и определить коэффициент турбулизации пластинчатого теплообменника. Результаты. Приведены результаты компьютерного моделирования движения теплоносителя в межпластинном гофрированном канале оригинального пластинчатого теплообменного аппарата с помощью программного комплекса Аnsys . Определены критерии устойчивости системы. Выполнено 3 D -моделирование канала, образуемого гофрированными пластинами. При исследовании процесса турбулизации были рассмотрены несколько скоростных режимов движения теплоносителя. Определен коэффициент турбулизации Tu, %. Выводы. В результате компьютерного моделирования установлено увеличение коэффициента теплопередачи К, Вт/(м ℃ ) за счет повышенной турбулизации потока, что приводит к снижению металлоемкости и уменьшению стоимости теплообменного оборудования. Statement of the problem. The heat exchange process occurring in a modified corrugated interplate channel of an intensified plate heat exchanger with an increased turbulence of the heat carrier is discussed. A computer model of the coolant movement in the speed range of 0.1-1.5 m/s is developed and the turbulence coefficient of the plate heat exchanger is determined. Results. The article presents the results of computer modeling of the coolant movement in the interplate corrugated channel of the original plate heat exchanger using the Ansys software package. The criteria of system stability are defined. 3D modeling of the channel formed by corrugated plates is performed. In the study of the process of turbulence several high-speed modes of movement of the coolant were considered. The turbulence coefficient Tu, % is determined. Conclusions. As a result of computer simulation, an increase in the heat transfer coefficient K, W/(m ℃) was found due to an increased turbulization of the flow, which leads to a decrease in metal consumption and a decrease in the cost of heat exchange equipment.

Computer simulation of high speed melting of amorphous silicon

1983 ◽  
Vol 43 (7) ◽  
pp. 669-671 ◽  
Author(s):  
H. C. Webber ◽  
A. G. Cullis ◽  
N. G. Chew
Keyword(s):  
Computer Simulation ◽  
Amorphous Silicon ◽  
High Speed

Effect of media overcoat on van der Waals interaction at the head–disk interface

2005 ◽  
Vol 97 (12) ◽  
pp. 126106 ◽  
Author(s):  
Raymond R. Dagastine ◽  
Lee R. White ◽  
Paul M. Jones ◽  
Yiao-Tee Hsia
Keyword(s):  
Van Der Waals ◽  
Van Der Waals Interaction ◽  
Head Disk Interface ◽  
Disk Interface
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