Modeling of interior nozzle flows for transient effects, realistic high performance nozzle physics and coupling to Large Eddy Simulation modeling of t

The objective of the present proposal is to develop and apply accurate, robust and cost-effective methodologies for the prediction of the interior nozzle flow, seamlessly coupled with high-fidelity large eddy simulation (LES) for the prediction of the jet plume and radiated noise. Based on the Phase I results, the meshing strategy and the wall modeling inside the nozzle were identified as the two elements which had the most significant and beneficial impacts of the flow and noise predictions. Looking towards application of the LES methodologies to realistic exhaust systems, the tasks proposed for Phase II focus on these topics, to enable robust meshing of complex internal parts, and to further improve the accuracy and efficiency of the predictions. The developments of Voronoi Mesh infrastructure (task 1), the physics-based grid adaptation (task 2) and the part-based meshing (task 4) all aim at simplifying the meshing process and reducing the burden on the users while maintaining high quality meshes for resolving the turbulent fluctuations. The development of the novel dynamic-slip wall model (task 3) would address some of the challenges of the current wall-stress model identified in Phase I (namely, appropriate modeling in regions of transition and separation, and better performance).