Project Title: Advanced modelling and simulation of sediment mobilization and resuspension
Doctoral Candidate: Evangelos PETRIDIS
Project Description: This project investigates the structural stability of the Brinkman–Forchheimer model for flows in porous media with variable porosity. Unlike constant porosity cases, variable porosity introduces key differences: the velocity field becomes compressible, the shear stress term involves the full deviatoric strain-rate tensor, and an additional term from normal stresses appears. We establish continuous dependence of solutions on physical parameters and derive bounds on kinetic energy decay. Building on this foundation, we perform 2D numerical simulations of bedform evolution in dense sand-water systems using a two-phase mixture-theoretic model. This model captures evolving sand-water interfaces and complex granular rheology. Simulations under unidirectional and oscillatory forcing reveal how flow and packing affect instability onset, bedform growth, and sand migration, offering insight into pattern formation in dense granular-fluid environments. Finally, we aim to extend the study to 3D numerical simulations to examine the three-dimensional nature of flow turbulence.