Advanced Flow Analyses in Complex Feed Systems

The development of simulation technology is proposed for carrying out high-fidelity transient analyses of systems that support experimental rocket testing such as control valves, feed system elements, pressure regulators and other flow control elements. The simulation technology comprises of a generalized multi-element unstructured framework (CRUNCH CFD) with integrated sub-models for grid adaption, grid movement and multi-phase flow dynamics including cryogenic cavitation. As part of our Phase I effort, simulations were performed for a series of systems that included the 10-inch LOX service valve, split-body valve, pressure regulator valve and the cavitating LOX venturi valve, all at constant valve settings. Results indicated excellent agreement with experimental flow coefficient curves. In Phase II, we will extend the framework to provide coupled valve motion - flow transient analyses with the development of an automated grid movement procedure to track valve motion. Valve timing analysis for a number of high pressure valve systems will be performed and the resultant dynamic events such as cavitation and valve chatter that lead to pressure fluctuations will be simulated. The framework will be used as an analysis support tool to generate performance metrics, evaluate design modifications and identify dominant frequencies associated with hydrodynamic instabilities and valve motion.