MOLD FILLING SIMULATION BY FINITE DIFFERENCE METHOD WITH HIGH ORDER SCHEME IN REGULAR CARTESIAN GRID
Finite difference methods in the regular Cartesian grid are often used for mold filling simulations. The main advantages of these methods are memory and CPU saving and ease of grid generation compared to other unstructured methods. However, representation accuracy of casting shape is very poor; for example, slopes or curves are represented as stair-steps. Therefore, in those cases, calculated results are rarely consistent with the actual phenomena. However, those disagreements would be caused not only by the poor representation of shape but also by the numerical error of the upwind scheme. Namely, it is expected that high order schemes give the more accurate solution without improving stair-step representation of casting shape. The aims of this work are to speculate about the error of stair-step representation, and to improve accuracy of the numerical analysis by CIP (Constrained Interpolation Profile) method as high order scheme. By speculating about the problem of stair-step approximation, it is found that inappropriate pressures are caused from numerical decay of flow velocity. The decay is proportional to the n-th power of the Courant number, if accuracy of scheme is time-space n-th order. In General the Courant number is less than 1. So the error of stair-step representation can be reduced by using the high order scheme. Some problems were solved by upwind scheme and CIP method. In the simulated results by the upwind scheme, the error of stair-step arises strongly. On the other hand, it was found that CIP method reduces the error.
Mold filling Finite difference method Simulation
Tomoki Sawada Koichi Anzai
Department of Metallurgy, Graduate School of Engineering, TOHOKU UNIVERSITY, 6-6-11-1009 Aoba Aramaki Aoba-ku, Sendai 980-8579, Japan
国际会议
大连
英文
131-138
2007-08-19（万方平台首次上网日期，不代表论文的发表时间）