Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
HIGH-ORDER CONSERVATIVE INTERPOLATION FOR UNSTEADY AERODYNAMICS APPLICATIONS
Submission Author:
Renan Santos , SP
Co-Authors:
Renan Santos, João Luiz F. Azevedo
Presenter: Renan Santos
doi://10.26678/ABCM.COBEM2021.COB2021-1373
Abstract
The capability of handling unsteady flow over complex geometries with efficiency and high-order accuracy is quite often desirable for the aerospace industry. Recent research on high-order overset flux reconstruction methods have shown successful results over moving boundary problems without the need of remeshing. The ability of accurately handling such type of requirements is very important, for instance, when addressing rotary wing flows and similar problems. In the present study, a high-order flux reconstruction solver is implemented coupled with a high-order conservative interpolation approach and a kd-tree algorithm over the mesh nodes for data communication in the overset regions. The flow is modeled by the 2-D Euler Equations discretized in space with a spectral difference method, a Roe approximate Riemann solver with Harten’s entropy correction for the flux reconstruction over the cell faces, and an explicit strong stability-preserving Runge-Kutta for time discretization. In the overset grid scenarios, two grids are generated: a background Cartesian mesh including all the fluid box domain and a near-body quadrilateral mesh. In order to determine which cell of the donor grid embeds a specific node in the receiver grid, both mesh nodes are implemented with a tree data structure expecting the logarithmic time complexity of O(k.logN) in the geometry search, where k is the order of flux points over the boundary interfaces of the receiver mesh and N the order of nodes in the donor grid. Furthermore, the solution is interpolated from the donor cell to the receiver grid point based on the donor cell polynomial expansion at the solution points and, then, imposed in a weak manner as a boundary condition to exactly reconstruct the flux with the approximate Riemann solver, as for any other interior face. The implementation is tested for different validation problems from the 5th International Workshop on High-Order CFD Methods (HiOCFD5). Additionally, accuracy and convergence studies are being performed on both single and overset grid approaches and compared to results in the literature.
Keywords
Overset grid, High-order methods, Unsteady Aerodynamics, Computational Fluid Dynamics
