Compressible multiphase flows play a key role in a large number of applications in the energy and transport sectors: nuclear power plants and safety (fast depressurisation, loss of coolant, flash evaporation), hydraulic energy, naval propulsion, CO2 capture and storage for carbon neutrality (pipe depressurisation involving evaporative cooling and thermal stresses), hydrogen technology for low-carbon aviation (cryogenic pumps), etc.
Physical and numerical modelling faces a number of obstacles because of the heat and mass transfers between phases that can occur out of thermodynamic equilibrium, the large variation in thermodynamic properties (from near vacuum to the critical point), the presence of high-intensity pressure waves (shock waves emitted by the collapse of bubbles, evaporation and condensation fronts) and the complex interaction with turbulent structures. Accurate prediction by numerical simulation is a real challenge, even for simple geometries, due to the difficulty of modelling the interfacial exchanges and small-scale turbulence interacting with multipĥase structures.
This project aims to contribute to the modelling of compressible multiphase problems related to energy systems by carrying out high-fidelity simulations. In particular, we will seek to develop a numerical approach able of taking small-scale effects into account in order to investigate realistic multiphase configurations. We propose to jointly address the following challenges:
- Develop well-posed two-phase models with regard to thermodynamic laws and complex interfacial exchanges;
- Build a large-scale numerical approach to study the complex interaction between turbulence and multiphase structures;
- Perform high-fidelity simulations of realistic configurations to analyse and gain a better understanding of physical phenomena and instability mechanisms, leading to improvements in the design and lifespan of these energy systems.
