Modelling liquid hydrogen flows in cryogenic conditions for low-carbon aviation

L’institut P’ est un laboratoire de recherche des domaines des Sciences Physiques et des Sciences de l’Ingénierie. Ses activités couvrent un large spectre de thématiques et de compétences complémentaires allant de la physique des matériaux à la mécanique des fluides, au génie mécanique et à l’énergétique.

Context
This study takes place in the context of the decarbonization of aviation, notably with the deployment of hydrogen as a fuel. The fluid has to be used in liquid form under cryogenic conditions (LH2 around 20 K). This requires for an adaptation of storage and supply systems, including the fuel circuit that carries hydrogen from the tanks to the engine.

In some cases, a vaporization phenomenon may develop within the axial pump (first element of the carburant pump), i.e. the liquid vaporizes under the effect of a local decrease in pressure, forming pockets of gas attached to the blades, leading to degraded pumping performance and strong vibrations. The design of these systems must therefore be capable of controlling the two-phase instabilities that can develop.

Despite the efforts made in this field, numerical simulation of multiphase hydrogen flows in cryogenic conditions still presents major scientific challenges: i) in terms of modeling phase change coupled with heat transfer between phases, and ii) in terms of thermodynamic behavior  (equations of state).

Objectives
The aim of the internship is to set up and test various models representing a compressible two-phase hydrogen flow involving non-isothermal liquid-vapor phase change. This requires adding source and/or sink terms to the various balances. A one-fluid formulation will be considered, with no-slip between liquid and gas phases.
The study is centered in compressible two-phase solvers developed in Pprime. The work will consist in testing different closure relations (relaxation models, heat transfer models) and also to plug thermodynamic tables at equilibrium (CoolProp library). Validation will be firstly carried out on simple academic cases, then on a NASA 2D hydrofoil for which experimental data are available. Comparisons will be made with the commercial software StarCCM+.

Skills in fluid mechanics, thermodynamics and numerical simulation.

Knowledges in two-phase flows will be appreciated.