Chattering in dynamic mathematical two-phase flow models

This paper describes a chattering phenomena present in the thermodynamic simulations of steam-water two-phase flow mathematical models. The models were developed with the Modelica modelling language and the Dymola tool. Modelica is an object oriented, acausal modelling language with a library of thermal fluid components, Modelica.Media, which includes an implementation of the IAPWS-IF97 (the International Association for the Properties of Water and Stream - Industrial Formulation 1997). The chattering phenomena is presented in a practical case: once-trough boiler, and several approaches are proposed to avoid this practical simulation problem.