Advanced Numerical Tools for Design and Analysis of In-Space, Valve and Feed Systems

In-space valves for the main fuel and oxidizer feed systems are required to provide precise control, wide throttling range and handle rapid on-off control. These design requirements result in significant unsteady, transient effects both on the fluid mass flow rate, as well as the torque required from the actuators controlling the valve. However, there currently are no fundamental analytical or numerical modeling tools that can predict the unsteady/transient performance of these valves; current design tools are limited to quasi-steady models and empirical correlations. The innovation proposed here is a high-fidelity, comprehensive numerical tool that can characterize the transient performance of these flight valves and provide design support. Geometry complexity and numerical accuracy problems associated with resolving valve configurations with moving surfaces are addressed via a grid adaption strategy within an unstructured framework. Unsteady effects due to both turbulence interactions as well as multi-phase cavitation are addressed with advanced numerical framework that incorporates both real-fluid thermodynamics for cryogens as well as advanced LES models for unsteady turbulence modeling. The tools and technology developed here would directly impact design support efforts for the J-2X upper-stage engine in the Ares 1 launcher envisioned under the Constellation program for the mission to the moon.