保存系支配方程式の高解像度スキームによる非定常層流圧力損失の高速高精度計算法

Abstract

A highly accurate unified computation of transient response in pipelines is desirable in order to improve pneumatic components. This paper deals with a high resolution simulation of transient response in laminar pipe flow by solving the governing equations directly. The authors employed a TVD scheme for computation of its stable and less diffusive properties. To apply this scheme, the governing equations must be described for a conservative system. The time-dependent friction loss in laminar pipe flow, which had only been discussed for a non-conservative system, was therefore transformed into a conservative system and solved with the Chakravarthy-Osher TVD scheme. Computations for a pneumatic pipeline with several pipe diameters were performed. The computations for the developed method were compared with the standard CIP method, and showed higher resolution, more stable computation and shorter computation time than the CIP method. The developed method can be easily applied to turbulent or high-amplitude pipe flow by simply changing the friction term.