Methods to Increase the Robustness of Finite-Volume Flow Models in Thermodynamic Systems

Energies

Sylvain Quoilin¹  Ian Bell²  Adriano Desideri²  Pierre Dewallef² 

[1] Thermodynamics Laboratory, University of Liege, Batiment B49, Chemin des Chevreuils 7, 4000 Liège, Belgium;

关键词: finite volumes;    chattering;    two-phase flow;    stiffness;    Modelica;   

DOI  :  10.3390/en7031621

来源: mdpi

【 摘 要 】

This paper addresses the issues linked to simulation failures during integration in finite-volume flow models, especially those involving a two-phase state. This kind of model is particularly useful when modeling 1D heat exchangers or piping, e.g., in thermodynamic cycles involving a phase change. Issues, such as chattering or stiff systems, can lead to low simulation speed, instabilities and simulation failures. In the particular case of two-phase flow models, they are usually linked to a discontinuity in the density derivative between the liquid and two-phase zones. In this work, several methods to tackle numerical problems are developed, described, implemented and compared. In addition, methods available in the literature are also implemented and compared to the proposed approaches. Results suggest that the robustness of the models can be significantly increased with these different methods, at the price of a small increase of the error in the mass and energy balances.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.