Interfacial Area Modeling for Eulerian Spray Simulations in Liquid Rocket Engines

Abstract

Contributions to Statistical Eulerian-Eulerian (SEE) flow models of two-phase flow are discussed in this article. Special attention is given to the Interfacial Area Transport Equation (IATE) which al-lows for sub grid scale modeling of exchange processes and a topological interpretation of continuous results. An interfacial area convection velocity is derived based on the assumption of strati-fied flow. This scheme will be shown to also hold in the limit of dilute spray. In the case of vanishing surface tension and heat of vaporization, disintegration of a supercritical jet can be described as a mixing rather than an atomization process. Following this assumption, growth of interfacial area due to stretching is dis-cussed and a new model term suggested. To resolve former diffi-culties with the interfacial area inflow boundary condition, an automatic interfacial area detection is proposed. This new term also allows for automatic creation of interfacial area in the case of unsteady injection or formation of a phase (e.g. condensation, cavitation, vaporization). The described model is implemented in the DLR finite volume TAU code.