The modified Reynolds equation for ultra-thin gas films between magnetic head; disk assembly is difficult to solve with conventional numerical methods, since the bearing number is very large; there exist boundary laye...The modified Reynolds equation for ultra-thin gas films between magnetic head; disk assembly is difficult to solve with conventional numerical methods, since the bearing number is very large; there exist boundary layers where pressure changes rapidly. An iterative finite difference algorithm is introduced to solve the nonlinear modified Reynolds equation, with special treatment for the abrupt change in the thickness of the gas film. The numerical results for two types of magnetic heads demonstrate that the scheme is effective.展开更多
When the decrease in the space between magnetic head and disk arrived at 10 nm or less, which is much lower than the mean free path of gas molecules, the gas flow presents distinctive features against the macro featur...When the decrease in the space between magnetic head and disk arrived at 10 nm or less, which is much lower than the mean free path of gas molecules, the gas flow presents distinctive features against the macro features because of the rarefied effects. The modified Reynolds equation considering rarefied gas effect is used to calculate the rarefied region of a negative pressure magnetic head working in the distance of 10 nm. Inverse Knudsen number was adopted to calculating the ratio of the rarefied area. According to the numerical resuks, discussions and analyses are then presented to reveal the rarefied effect on the working performances of a magnetic head. The results show that the magnetic head works in the slip-flow and transition regions and moves to the transition region with the increase in velocity. Furthermore, the maximum rarefied effects occur at the side edges where the flying height is thinner and pressure is lower, rather than in the minimum flying height on the rear. The results also show that with considering the rarefied effects, the load-carrying capacity of the magnetic head and the maximum pressure decrease significantly, but the minimum pressure slightly changes.展开更多
This paper introduces some final results of some key technologies in magnetic disk drives. We dicuss the design and experiment of thin film head, magnetic fluid exclusion seal system, head disk interface and the engin...This paper introduces some final results of some key technologies in magnetic disk drives. We dicuss the design and experiment of thin film head, magnetic fluid exclusion seal system, head disk interface and the engineering appilcations of these technologies in magnetic disk drives.展开更多
基金Supported by the Project of the State Key Basic Research and Development of China (Grant No. 2003CB716205)
文摘The modified Reynolds equation for ultra-thin gas films between magnetic head; disk assembly is difficult to solve with conventional numerical methods, since the bearing number is very large; there exist boundary layers where pressure changes rapidly. An iterative finite difference algorithm is introduced to solve the nonlinear modified Reynolds equation, with special treatment for the abrupt change in the thickness of the gas film. The numerical results for two types of magnetic heads demonstrate that the scheme is effective.
基金supported by National Basic Research and Development Program of China (973 Program, Grant No. 2003CB716205)
文摘When the decrease in the space between magnetic head and disk arrived at 10 nm or less, which is much lower than the mean free path of gas molecules, the gas flow presents distinctive features against the macro features because of the rarefied effects. The modified Reynolds equation considering rarefied gas effect is used to calculate the rarefied region of a negative pressure magnetic head working in the distance of 10 nm. Inverse Knudsen number was adopted to calculating the ratio of the rarefied area. According to the numerical resuks, discussions and analyses are then presented to reveal the rarefied effect on the working performances of a magnetic head. The results show that the magnetic head works in the slip-flow and transition regions and moves to the transition region with the increase in velocity. Furthermore, the maximum rarefied effects occur at the side edges where the flying height is thinner and pressure is lower, rather than in the minimum flying height on the rear. The results also show that with considering the rarefied effects, the load-carrying capacity of the magnetic head and the maximum pressure decrease significantly, but the minimum pressure slightly changes.
文摘This paper introduces some final results of some key technologies in magnetic disk drives. We dicuss the design and experiment of thin film head, magnetic fluid exclusion seal system, head disk interface and the engineering appilcations of these technologies in magnetic disk drives.
