Speaker
Description
Starting from the microscopic description of gas mixtures, a rigorous kinetic foundation is essential for capturing the complex interfacial dynamics often missed by phenomenological models. In this talk, we investigate the formal hydrodynamic limit of the multispecies Boltzmann equation, specifically in a regime where intra-species collisions are the dominant physical process [1]. By analyzing the asymptotic behavior as the Knudsen numbers approach zero, we derive the isentropic two-phase flow model originally proposed by Romenski and Toro [2]. This derivation provides a justification for multivelocity and multi-pressure frameworks, allowing for the explicit computation of model coefficients. Furthermore, we demonstrate how this kinetic scaling naturally accounts for the evolution of the volume fraction, bridging the gap between kinetic theory and macroscopic multiphase flow.
This is a joint work with Gabriella Puppo (Sapienza Universita di Roma) and Thomas Rey (Université Côte d’Azur).
[1] Gabriella Puppo, Thomas Rey, and Tommaso Tenna. Formal derivation of an isentropic two-phase
flow model from the multispecies boltzmann equation. Phys. Rev. E, 113:034119, 2026.
[2] Evgeniy Romenski, Dimitris Drikakis, and Eleuterio Toro. Conservative models and numerical methods for compressible two-phase flow. J. Sci. Comput., 42(1):68–95, 2010.