Multiple-field systems dynamic modeling, Part I: Physical decomposition of multi-physical systems, a bond graph approach

In coupled-field studies, compatibilities of different fields' solutions are as important as the solutions themselves, as they directly affect the investigation results that the solutions of the individual fields are intended to provide. This paper aims to address this issue in fluid-structure-interaction (FSI) studies by proposing an effective framework with which the compatibility of the solid and fluid fields' solutions is guaranteed prior to the derivations of the individual solutions. To this aim, the role of the classical assumptions used by conventional approaches in FSI studies is first analyzed, and their impact on the drawbacks of the conventional approaches is revealed. A physical-decomposition framework based on the Bond graph terminology is then designed in which inherent physical connections between the components of coupled fields are exposed and systematically accounted for by the use of a continuous dynamic data-transaction network between the fields. The proposed framework is seen to overcome the drawbacks of its conventional counterparts, and to address the FSI compatibility issue satisfactorily. It offers a unique strategy for effective multi-physical multiple-field systems dynamic modeling.