Chattering in dynamic mathematical two-phase flow models

This paper presents a chattering problem which arises in a dynamic mathematical two-phase flow model. The real system under study is also introduced, the DISS test facility, a parabolic-trough solar thermal power plant. The heat transfer fluid in the DISS facility is the steam-water mixture. A dynamic model of this plant, using Modelica as the modeling language, was previously developed in order to study its behavior. Chattering arises in the pipe model reducing the computational performance and hence limiting the applicability of the model. The problem source is studied and analysed together with an approach to the problem which is based on the smooth interpolation of some thermodynamic properties.