THIS GRANT IS A CONTINUATION OF N00014-13-1-0827 FY13 SBA NNR AIRCRAFT - Strand Grid Methodology for Dynamic Ship/Aircraft Interaction Simulations
Abstract
FY16 funds are provided to continue the four main tasks defined to achieve the overall research goals.Tasks 1 and 2 involve the investigation of two different approaches for achieving efficient high-order accuracy on strand grids. Both methods represent emerging paradigms in high-order methods. Task 3 involves the extension of high-order strand grid methods to overset systems using techniques that preserve accuracy and efficiency. Task 4 involves the demonstration of the strand-Cartesian approach to unsteady multi-body problems, including VDI flows of interest to the Navy. Portions of tasks 3-4 will be performed through a sub-award to Jay Sitaraman at the University of Wyoming.Task 1: High-order flux correction (FC). The PI s recently introduced third-orderaccurate flux correction (FC) scheme will be extended to fourth and higher orders for 3D viscous flows involving high aspect ratio strand grids. Subtask 1.1: Energy stability analysis. The FC method will be formulated topossess good stability characteristics, both in terms of L2 energy norms as well aslocal extremum diminishing (LED) and total variation bounded (TVB) propertiesat shocks.Subtask 1.2: Viscous Extension. Options for including viscous terms in the FCmethod will be explored, including continuous Galerkin finite element approaches, and derivations arising from hyperbolic systems that encompass diffusion terms.Subtask 1.3: Extension to strand grids. The semi-structured nature of strandgrids will be exploited to provide the necessary high-order accurate gradients along strand directions and to facilitate line-based solution procedures.Task 2: Comparison of FC with high-order flux reconstruction (FR). A rigorous comparison of the FC method of Task 1 with another promising new high-order method known as flux reconstruction, will be performed for canonical inviscid, viscous, and unsteady flows. FC and FR represent two different approaches to high-order, FC being continuous with extra-cell stencils, FR being discontinuous with intra-cell stencils.Subtask 2.1: FR methodology for strand grids. The FR naturally lends itselfto efficient implementation on strand grids through prism-based tensor productsand line-decoupled implicit solution procedures.Subtask 2.2: Comparison of FR and FC for canonical cases. Test cases to beperformed include those of the recent high-order workshops sponsored by DLR,AIAA, and AFOSR. These cases range in difficulty from 2D steady inviscid flowsto 3D transitional flows.Task 3: High-order overset interpolation. Both FC and FR have the potential toprovide high-order accurate solutions for strand overset systems provided proper treatment is given at overset boundaries. Numerical tests will be performed to determine optimal methods of minimizing conservation errors and improving convergence rate. Collaboration will potentially be pursued with Mavriplis and Sitaraman on related ONR proposed research to interface with a discontinuous Galerkin off-body solver.Task 4: Application of strand-Cartesian grids to VDI flows. Three problems willdemonstrate strand-Cartesian methodology for VDI flows:Subtask 4.1: Blade-vortex interaction (BVI). The ability of strand-Cartesianmethods to handle dynamic geometry and hole-cutting for multiple bodies willbe evaluated using a parallel wing upstream of a two-bladed rotor configuration.Computational results will be compared to experimental data obtained by Kitaplioglu, et al. and to previous computations with traditional meshes.Subtask 4.2: VDI for fixed-wing. The ability to simulate an approaching fixed-wingaircraft interacting with an uneven and discontinuous ship surface will betested using a generic fighter configuration vehicle landing on a simplified carriergeometry. The aircraft will perform a prescribed maneuver through the turbulentship airwake.Subtask 4.3: VDI for rotary-wing. The ability to simulate an approachinghelicopter interacting with an uneven and discontinuous ship surface will be tested using a UH-60A
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 26, 2018
- Source ID
- N000141612074
Entities
People
- Aaron Katz
Organizations
- Office of Naval Research
- United States Navy
- Utah State University