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Use of characteristics method with cubic interpolation for unsteady‐flow computation
Author(s) -
Yang JinnChuang,
Chiu KuangPing
Publication year - 1993
Publication title -
international journal for numerical methods in fluids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 112
eISSN - 1097-0363
pISSN - 0271-2091
DOI - 10.1002/fld.1650160405
Subject(s) - interpolation (computer graphics) , linear interpolation , mathematics , computation , flow (mathematics) , algorithm , numerical analysis , numerical stability , mathematical analysis , computer science , geometry , animation , computer graphics (images) , polynomial
The specified‐time‐interval (STI) scheme has been used commonly in applying the method of characteristics (MOC) to unsteady open‐channel flow problems. However, with the use of STI scheme, the numerical error for the simulation results can always be induced due to the interpolation used to approximate the characteristics trajectory. Hence, in order to remedy the numerical errors caused by the interpolation, one needs to seek some kind of interpolation technique with higher‐order accuracy. Instead of the linear interpolation technique, which has been used very commonly and can induce serious numerical diffusion, the Holly‐‐Preissmann two‐point, method, which is a cubic interpolation technique with fourth‐order of accuracy, is proposed here to integrate with the method of characteristics for the computation of one‐dimensional unsteady flow in open channel. The concept of reachback and reachout in space and time directions for the characteristics is also introduced to assure the model stability. The computed results from this new model are compared with those computed by using the Preissmann four‐point scheme and the multimode method of characteristics with linear interpolation.