The first three-dimensional problem we consider is flow past a NACA 0012 airfoil with plates attached to each end. We impose uniform upwind boundary conditions at inflow and outflow, and the domain is periodic from one end of the airfoil to the other.
This is a simple model of a wing between an engine and fusalage. The
domain was meshed with SIMPLEX2D [83] and extruded using
1960 prisms and 2095 hexahedra. A thin boundary layer of
hexahedra was used on the surface of the wing and the simulation was
run with upto 4th order expansion and Re=2000 (based on chord length). A
summary of the simulation parameters is given in
7.6.
| Parameter | Value |
| Dimension | 3d |
| Re | 2000 base on chord length |
| Mach | 0.5 |
 |
1e-4 |
| N-Range | 1 to 4 |
| KPrisms | 1960 |
| KHex | 2095 |
| Method | Discontinuous Galerkin |
At low-order the simulation ran to steady state. This is due to a reduced effective Reynolds number achieved because of numerical dissipation. As we increased the order we saw unsteadiness developing in the wake of the wing, and what appears to be oblique shedding. This is only a marginally three-dimensional domain but it does demonstrate the ability of to direct resolution into boundary layers and to fill out a domain with larger elements.
 |
