Research database

The aim of the THEMAS project is to forge a physical understanding on several microscale aspects of heat and mass transfer in fluid flows with focus on mixtures and their interactions with micro- and nano-textured smooth and rough walls with controlled wettability. High-fidelity interface-resolved numerical simulations will provide unprecented details whereas novel laboratory experiments will enable us to explore a wide range of different configurations, and not only validate the numerical model. Phase change is the most efficient way to increase heat transfer since latent heat is typically much larger than sensible heat. It is one among the challenges we need to tackle to meet the rising global energy demand in a sustainable manner. Better understanding the mechanisms by which the system microstructure (the nucleii of the second phase, the wall temperature, surfactant distribution and species concentration, as well as the wall topology and chemical properties) determines the global heat transfer, is crucial for many applications involving heat transfer. While recent advances in micro- and nano-fabrication techniques are providing new technological opportunities, we lack highfidelity models capturing how the underlying small-scale physiochemical processes affect the large-scale flow and the global heat- and mass-transport. A better prediction of the interfacial fluxes in non-ideal fluid mixtures will therefore have a huge impact on engineering solutions. To reach the objectives, the team will develop a high-fidelity numerical tool for numerical simulations of compressible multiphase flows. Simulations of multiphase flows are one of the challenges ahead of us, where advances will come mostly from more generic formulations, able to efficiently exploit modern accelerated architectures. Here, we propose the Baer-Nunziato diffuse-interface framework for multiphase systems with chemical disequilibrium. The experiments will enable us to investigate the different processes under fully controlled conditions of wall texture, ambient flow and temperature/humidity. The type of experiments and simulations proposed here will open new avenues for physics-based engineering models, with an impact we anticipate similar to that of the first fully resolved simulations of turbulence few decades ago.