The first test case is the CERFACS CO-VO, already performed on many codes.
Definition
An isentropic vortex is simply moving to the east of a periodic square grid. With time. The flow is supposed inviscid Euler Equations.
| CO-VO Parameters | |
|---|---|
| Density | 1.1608 Kg/m3 |
| Temperature | 300 Kelvins |
| Pressure | 10^5 Pascals |
| Circulation | 34.728 |
| Radius | 0.005m |
| Convection speed | Uc = 170m/s (Mach 0.5) |
| Resolution | 64×64 |
| Domain | -0.05, 0.05 m |
For further details on the initialization equations, download the Cerfacs technical report here.
Secondary test: unaligned convection
In LBM, the streaming operator is aligned with the grid. Therefore a vortex convection from west to east is a very good situation: only one direction is really working.
The secondary test is simply a convection with an angle, exactly atan (1/10) / pi180. = 5,71059314 degree*.
Therefore, after 10 revolution, the vortex should still be in the center.
The only difference is a small velocity component to the Y direction (south to north).
| Unaligned CO-VO | |
|---|---|
| Convection speed x | Uc = 170m/s (Mach 0.5) |
| Convection speed y | Vc = 17m/s |
Article originally written by Antoine Dauptain (CERFACS), research scientist focused on computer science and engineering topics for HPC.