Title: low Mach two-phase flow modeling with high heat transferts
In this presentation, we are interested with modeling the flow of a heat transfert fluid (water) inside a nuclear reactor core.
To this purpose, we first present a low Mach simplified model with three equations (obtained as the low Mach limit of a compressible model, the HEM model), which lies on a pressure decomposition into a thermodynamical pressure (which is involved in the state equation) and a dynamical pressure (involved in the momentum equation). This decomposition has several advantages, in terms of obtaining exact and asymptotic solutions, but also from the numerical point of view.
We then study a new model (with four equations) describing the low Mach two phase flow behavior, which can be obtained as the low Mach limit of the HRM model. After giving some model properties, we show its convergence to the previous (three equations) model in the instantaneous relaxation regime. We introduce a scheme preserving the asymptotics which enables numerical simulations of the spatial coupling between the two regions with different characteristic relaxation times.
This is a joint work with Gloria Faccanoni and Yohan Penel.