| STAGES ityp [COEFFICIENTS x1 x2 ... xn] [zone_selector] |
For structured grids, this keyword allows the user to use a Runge-Kutta time stepping option. The parameter ityp specifies the number of stages, and x1 x2 ... xn specify the coefficients. The following ityp values are available:
| ityp | Stages | Order | Description |
|---|---|---|---|
| 0 | 1 | 1 | Backward Euler method |
| 1 | 4 | 2 | Jameson style low-storage Runge-Kutta |
| 2 | 6 | 3 | Williamson's low-storage Runge-Kutta |
| 3 | 2 | 3 | Van Leer-Tai-Powell optimal smoothing method |
| 4 | 3 | 3 | Van Leer-Tai-Powell optimal smoothing method |
| 5 | 3 | 3 | Wray's minimal storage Runge-Kutta |
| 6 | 9 | 4 | Wray's minimal storage Runge-Kutta |
| 7 | 2 | 2 | Simple two-stage Runge-Kutta |
The number of required coefficients and their default values are:
| ityp | # Coefs | Default Values |
|---|---|---|
| 0 | 0 | n/a |
| 1 | 4 | 1/4, 1/3, 1/2, 1 |
| 2 | 6 | 0, 1/3, -5/9, 15/16, -153/128, 8/15 |
| 3 | 2 | 1/3, 1 |
| 4 | 3 | 0.1481, 0.40, 1 |
| 5 | 5 | 1/4, 8/15, 0, 5/12, 3/4 |
| 6 | 9 | 0.13777497, 0.41883005, 0.38832895, 0.88635766, 0.14633970, -1.0364937, 0.0037218696, -0.087624810, 0.32383451 |
| 7 | 2 | 1/2, 1 |
Last updated 30 Sep 2016