Part IIB: Computational Multi-Fluid Dynamics
Part IIB reflects the growing interest in the application of CFD techniques to multi-phase flows and covers the most common computational techniques. The introductory chapters from a book authored by Tryggvason, Scardovelli and Zaleski will be emailed to the participants in Part IIB to prepare them for the lectures.
Thursday (8:30-13:00 and 14:30-18:00)
13B. Introduction to CMFD
Interpenetrating media approach, phase averaging / void fraction; Two-fluid formulation in the RANS concept, boiling & condensation; One-fluid formulation; Population balance approach. Part B:Lagrangian particle tracking (1,2 & 4-way coupling).
14B. Introduction to RANS modelling of two-phase flows
Overview of single fluid & multi-fluid modelling in CMFD. Turbulence in multiphase flows: scale separation; averaging and filtering; from RANS to
LES, through DNS
15B. Introduction to Interface Tracking
Need for numerical simulations and history. Overview of the governing
.equations and standard solution methods. Introduction to the various methodsused to track sharp fluid interfaces.
16B. Volume of Fluid (VOF) method
Volumetric tracking, piecewise linear interface reconstruction. Advanced VOF methods: unsplit, exactly-conserving VOF methods, oct-tree adaptive mesh refinement, height-function methods. High-density ratio and momentum-conserving methods.
17B. Applications of VOF, Phase Field and Lattice Boltzmann
The Gerris, ParisSimulator and Basilisk free codes. Flows with large interface deformation and disruption. Ligament formation, atomization and entrainment. Droplet splashing. Multiphase flow in porous media. Introduction to the Phase-Field / Cahn-Hilliard model. Multiphase Lattice Boltzmann. Lattice Boltzmann at high density ratio.
Friday (8:30-12:30)
18B. Embedded Interface Methods
Interface tracking for direct numerical simulations (DNS) of multiphase flows. Applications to bubbly flows and flows with phase change and mass transfer. Multiscale issues.
19B. Application of CFD codes to complex multiphase flow systems
Introduction to different modelling approaches for multiphase flows, including Multi-component systems with mass transfer. Treatment of local heat transfer with phase change, using Interface Tracking and Phase averaging. Compressible multiphase flows with phase change. Applications: PTS, Condensing jets, Nucleate and convective flow boiling, Water hammer.