Numerically robust co-simulation using transmission line modeling and the Functional Mock-up Interface

Modeling and simulation are important tools for efficient product development. There is a growing need collaboration, interdisciplinary simulation, re-usability of models. This usually requires to be coupled together co-simulation. However, the usefulness co-simulation often limited by poor performance numerical instability. Achieving stability especially hard stiff mechanical couplings. A suitable method use transmission line modeling (TLM), which separates submodels using physically motivated time delays. The most established standard tool coupling today Functional Mock-up Interface (FMI). Two example models in one dimension three dimensions used demonstrate how next version FMI can conjunction with TLM. properties TLM also proven analysis. Results show that ensured without compromising on performance. With current standard, this tailor-made custom solutions interpolation input variables. Without solutions, variables must exchanged sampled communication extrapolation. In case, improved reducing step size. it shown cannot achieved even when unacceptably small steps. motivates include an intermediate update mode, where interchanged between points. It suggested should extended optional callback functions providing output requesting