The proposed work develops a framework for uncertainty quantification (UQ) for CFD solutions for computational platforms of interest (Task 1) and develops strategies for improving predictive capability of RANS and RANS-LES techniques (Task 2).

This proposal develops new strategies for predicting the performance of high-speed airbreathing propulsion systems using data-driven techniques. The project will involve researchers at the University of Michigan, Spaceworks, and NASA as well as two departments (MAE and NE) at NCSU.

The proposed effort will perform a complementary experimental and computational investigation of the scramjet inlet performance at sub-design Mach numbers.

This work will conduct large-eddy and direct numerical simulations of ethylene-fueled combustion in an inlet / isolator / combustor rig operational at the University of Illinois. Research issues include determination of the physical mechanisms that lead to the onset of thermal choking, upward propagation of pressure disturbances, and eventual transition to stable dual-model operation. Out-year tasks include simulations of combustion in non-axisymmetric flowpaths and predictive simulations of scramjet operation in the University of Queensland's R3X reflected-shock tunnel.

Intergovernmental Personnel Act Agreement for Dr. Jack R. Edwards, Department of Mechanical and Aerospace Engineering.

This work will support the Ph.D research of Andrew Navratil. The focus will be the development analysis techniques for quantifying the influences of unresolved turbulent fluctuations on apparent reactivity as expressed at the scales resolved during the simulation. NC State's multi-resolution analysis using mesh-sequenced realization (MRA-MSR) techniques will be used to examine the relative performance of several proposed closures for subgrid turbulence chemistry interactions and to develop optimal forms that may improve performance. A second thrust will be to use data-mining techniques under development at NCSU to improve Reynolds-averaged Navier-Stokes modeling of turbulence / chemistry interactions.

This is a computational investigation into the physical mechanisms that lead to the onset of boundary layer transition (BLT) within the swallowing distance of the entropy layer on slender hypersonic vehicles with blunt, hemispherical or ogival nosetips.

This proposal to NCSGC will support our AIAA DBF team by providing funds to construct their aircraft.

The proposed will develop new strategies for Reynolds-averaged Navier-Stokes (RANS) and hybrid large-eddy simulation / RANS modeling for hypersonic shock / boundary layer interactions. The approach will utilize wall-resolved large-eddy simulations, anchored using relevant experimental data, to provide information that can be used to refine and improve both classes of lower-fidelity models. Specific attention will be devoted to examining turbulence length scale evolution through a shock / boundary layer interaction, turbulence production near unsteady shock waves, and turbulent transport of energy to the surface, with a view toward incorporating more exact effects for these processes in engineering level models. An additional task will determine 'best practices' for comparing computational solutions with legacy experimental data sets for hypersonic flows. The University of Tennessee will be a subcontractor to this effort. UT will implement improved RANS and LES/RANS models developed by NCSU into COFFE, the higher-order finite-element branch of CREATE-AV's Kestrel suite of flow solvers.

The National Institute of Aerospace (NIA) proposes this collaborative research effort with Computational AeroSciences Branch at NASA Langley. The Principal Investigator (PI) will contribute to the development of effective iterative solution strategies to bridge the gap between the present DOF limit and the much larger problem sizes in practical aerospace applications. This will include but not be limited to implementing promising algorithms and evaluating their efficacy for robust & dependable solution for systems of interest. The principal purpose of this research is to establish the feasibility of iterative solvers for parameter studies of wave propagation problems encountered in aerospace applications, with an emphasis on laminar-turbulent transition and aeroacoustics. The expected outcomes include a knowledge base pertaining to the performance of candidate algorithms for the solution of large, linear algebraic systems and a technical report documenting the research findings.