Dynamic Hybrid RANS/LES Modeling of Interior Nozzle Flows and Jet Plumes

ATA Engineering proposes to simulate complex interior and exterior flowfields of hot, supersonic aircraft engine nozzles by applying a novel dynamic hybrid RANS/LES (DHRL) modeling framework coupled to the Loci/CHEM (CHEM) finite-volume flow solver. DHRL is code- and turbulence model-independent. It dynamically determines the appropriate interface between large eddy simulation (LES) and Reynolds Averaged Navier-Stokes (RANS) portions of a computational domain, ensuring smooth and continuous turbulence production across the interface. It has been validated on attached and separated flows ranging from transitional cardiovascular devices to very high Reynolds number ship hydrodynamics. CHEM is a massively parallelizable solver for highly compressible flows both with/without real gas properties and chemistry. The technical approach will first demonstrate and validate that DHRL provides LES accuracy at hybrid RANS/LES costs on a test problem relevant to high-performance engine nozzles. Best practices for grid generation, time stepping, and turbulence model selection will then be applied to full nozzle simulations on a government-furnished geometry. Finally, a technical plan will be outlined for inclusion of real geometry effects including throttle transients, advanced wall boundary conditions, and realistic inflow turbulence.