Dynamic Hybrid RANS/LES Modeling of Interior Nozzle Flows and Jet Plumes Navy SBIR FY2013.2 Sol No.: Navy SBIR FY2013.2 Topic No.: N132-102 Topic Title: Dynamic Hybrid RANS/LES Modeling of Interior Nozzle Flows and Jet Plumes Proposal No.: N132-102-0843 Firm: ATA Engineering, Inc 11995 El Camino Real Suite 200 San Diego, California 92130-2566 Contact: Parthiv Shah Phone: (858) 480-2101 Web Site: www.ata-e.com Abstract: 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. Benefits: The primary benefits of the technology is that it will allow simulation and modeling of interior flows in high performance turbine engine exhaust nozzles at a level of accuracy that has not been achievable to date and full coupling of the interior and exterior regions without the need for ad hoc assumptions. Applications of these tools and methods to engine development programs will enable the design, evaluation, and optimization of advanced nozzle technologies that can meet the ever more challenging performance requirements. The downstream benefits of using highly accurate simulation methods early in the design cycle include reduced technology risk and reduced development cost and schedule. The initial commercial market for this technology is in providing services and software tools to the developers of next generation military and commercial jet engines. Both military and commercial aircraft programs are under increasing pressure to develop engines that offer higher performance, higher durability, and reduced noise signature. The methods and tools that will be developed here will be a key enabler in the design of advanced nozzle hardware that can contribute to these goals. The methods will also be directly applicable to the development of rocket engines, launch vehicles, and supersonic and hypersonic vehicles where similar high-speed flow simulation challenges exist. Return