Humboldt-Universität zu Berlin - Mathematisch-Naturwissenschaftliche Fakultät - Institut für Mathematik

Preprint 2019-06

Diana Estévez Schwarz und René Lamour


A Projector Based Decoupling of DAEs obtained from the Derivative Array. 


Abstract: The solution vector of a differential-algebraic equation contains different types of components, depending on their properties. In this paper, we particularly present an orthogonal decoupling that, for higher-index DAEs, describes in which context these orthogonal components appear in the derivative array. In this sense, we characterize different types of so- called “higher-index” components with regard to the explicit and hidden constraints. As a consequence, for linear DAEs we obtain a straightfor- ward possibility to determine a projected explicit ODE and compare it with the so-called inherent regular ODE related to the projector-based decoupling associated with the tractability matrix sequence. By several examples we illustrate the differences of these two projector-based ap- proaches and discuss their relationship.


Preprint series: Institut für Mathematik, Humboldt-Universität zu Berlin (ISSN 0863-0976), 2019-06


27 pp.