The variability constraints in simulation of index-2 differential-algebraic processes

In the article a general simulation task of index-2 differential-algebraic equations (DAEs) is considered. To overcome difficulties connected with a nonlinear process dynamics, a new constraints type - the variability constraints - was introduced. The designed solution procedure is based on a multiple shooting method - it was assumed, that process dynamics in each shooting interval is constant. Therefore, the presented methodology can be treated as an extended direct shooting approach for simulation of the index-2 DAE equations with the variability constraints, which have an important practical application in various areas of applied informatics, e.g. manufacturing process modeling, simulation and optimization. Finally, the presented methodology was investigated on a two-phase reactor simulation task, which was described by the index-2 differential-algebraic equations.