Review of the Modelling of Slush Hydrogen Flows

Abstract

In the perspective of mass savings related to future launchers, the use of slush hydrogen as propellant is attractive. Due to its higher density, the use of slush hydrogen could lead to the mass reduction of propellant and the utilisation of smaller tanks. However, the use of slush hydrogen in rocket engines presents different challenges. The first one is the production of slush hydrogen. Other aspects are the problems induced by the use of slush in a propulsion system: slush flow in pipes and singularities, design of a compatible turbopump and injection of slush in a combustion chamber. In order to prepare numerical tools for supporting future technical activities, ISA has undertaken a large effort in the direction of the modelling of slush hydrogen flows. The work has been split in two parts: the engineering modelling for slush flows in pipe lines and the preparation of more advanced models. At first, an extensive review of the available studies on this topic reported in the literature has been undertaken. Then, an engineering model has been selected and incorporated in a numerical tool. The different issues in term of modelling related to slush hydrogen have been identified and a potential model for future computational fluid dynamics calculations has been selected.