Description: This project is geared towards a computationally efficient, robust computational fluid dynamics (CFD) tool for simulating unsteady multiphase flows of critical importance to NASA in their ground and launch systems processing technologies. The proposed work seeks significant cost reduction for unsteady simulations via the PIMPLE algorithm in the Loci-STREAM CFD code. The basic PIMPLE algorithm for pressure-velocity coupling has been implemented in Loci-STREAM for incompressible laminar/turbulent flows and a speedup of a factor of three has been demonstrated. The proposed Phase I project will extend the PIMPLE-based methodology to handle compressible flows followed by coupling with the cavitation capability in Loci-STREAM. This will allow unsteady simulations of cavitating flows of interest to NASA with significantly reduced turnaround times. The long-term objective is to extend this unsteady methodology to other selected multiphase applications (such as turbulent combustion) along with enhancements to the overall algorithm in Loci-STREAM, including implementing a fully coupled flow solver, implementing more efficient matrix solvers, etc.

Benefits: Modeling of cavitation in cryogenic propellant tanks, valve flows, and run lines Modeling of transient fluid structure interaction (FSI) between cryogenic fluids and immersed components to predict the dynamic loads, frequency response of facilities Modeling of water jets for flow tests on the B-2 test stand Water deluge mitigation for rocket launch induced environments Subcritical injector analysis for gas generators, preburners and thrust chambers

Multiphase applications for Air Force and Navy applications involving non-reacting & reacting flows. Simulation for cavitating flows and reacting flows at companies dealing with space propulsion, gas turbine, diesel engines, etc. Loci-STREAM code is being used at Aerojet Rocketdyne for rocket engine combustion simulations