Multiphysics Coupling in the Non-Isothermal Analysis of Elasto-Viscoplastic Material Under Variable Hydro-Thermomechanical Conditions

This study presents the development of a numerical model of a tubular heat exchanger subjected to varying hydro-thermomechanical conditions in a solar power plant in Morocco. The anisothermal behavior of the exchanger material is also investigated. Initially, the focus is placed on selecting an appropriate geometric modeling approach, distinguishing between a local model concentrating on specific components and a global model considering the entire structure. The second part involves the use of numerical simulations to analyze heat transfer and fluid flow within the local geometry of the tubular exchanger. The governing equations for the elasto-viscoplastic material are incorporated to establish a robust multiphysics coupling. The third section outlines the physical equations that describe the phenomena within each domain under investigation. The fourth section is devoted to the implementation of a strong multiphysical coupling simulation, aimed at validating the proposed thermal model of the exchanger with experimental data and confirming the thermo-mechanical behavior of the exchanger material. Finally, numerical consolidation curves of the constitutive law and the Rochet effect characterizing the anisothermal material behavior are compared with established results from the literature.