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

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.

Author(s):  
Wei Hua ◽  
Jianhua Li ◽  
Bo Liu ◽  
Yansheng Ma

The unstructured triangular mesh is successfully applied to the steady simulations of the slider due to its flexibility, accuracy and mesh efficiency in capturing various complex ABS rails and recess wall regions. This paper introduces a new implicit algorithm with second order time accuracy for the time-dependent simulations of the slider dynamics based on the unstructured triangular mesh. The new algorithm is specially developed for the unstructured triangular mesh and the finite volume method. It is applied to simulate the load/unload details based on the 9-D model, such as the influences of the limiter position on the flying height during the unload process, and the development and the 3-D profiles of the air bearing pressure during the load process. Because of the mesh efficiency of the unstructured triangular mesh and the flexibility of applying greater time steps, the simulation times are significantly shorter than those of the structured rectangular mesh. The simulation results based on the algorithm are in good correlation with the experimental results.


2021 ◽  
Vol 2119 (1) ◽  
pp. 012152
Author(s):  
D V Platonov ◽  
A V Minakov ◽  
A V Sentyabov

Abstract The paper presents a numerical study of the free discharge of water through the turbine with a braked runner. The simulation was carried out for a unit of a full-scale Francis turbine. The finite volume method was employed for unstructured meshes using the DES method. The simulation results show the flow structures, integral characteristics, and pressure pulsations in the flow path. The analysis of the applicability of this approach to real conditions is carried out.


Author(s):  
George Tzabiras ◽  
Vlasia Papadopoulou

The present work deals with the numerical simulation of accelerating and decelerating motions of a submerged body of revolution, in order to investigate the influence of the thrust variation on the maneuvering characteristics. A finite volume method is adopted to solve the essentially 2D RANS, time-dependent equations in a body-fitted co-ordinate system. Two problems have been examined for a 50m body of revolution: (a) the stopping maneuver, i.e. crash stop from steady forward speed and then full astern and (b) full ahead at steady speed from rest and then full astern.


1993 ◽  
Vol 107 (2) ◽  
pp. 324-337 ◽  
Author(s):  
San-Yih Lin ◽  
Tsuen-Muh Wu ◽  
Yan-Shin Chin

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