{HLLE | RUSANOV} EPSS epss [zone_selector] |
This keyword allows the user to control the behavior of the anti-diffusion term in the HLLE and Rusanov schemes for structured grids. The parameter epss is used in the computation of a switch used to regulate the anti-diffusion terms. The possible values for epss are shown below.
epss | switch | Result | |||
---|---|---|---|---|---|
0.0 | 1.0 | Anti-diffusion terms are always fully on. | |||
> 0.0 | 1.0 − epss |pscal| | Anti-diffusion terms are on, scaled by the absolute value of a pressure gradient scaling parameter pscal, with epss as a coefficient. The result is that the anti-diffusion terms are smaller in regions where the pressure gradient is changing rapidly. Larger values of epss result in smaller anti-diffusion terms. The switch is limited to a minimum value of 0.0 (fully off). | |||
< 0.0 | 1.0 + epss | Anti-diffusion terms are on, with the switch hard-wired to the indicated value. Larger negative values of epss result in smaller anti-diffusion terms. The switch is limited to a minimum value of 0.0 (fully off), which corresponds to epss = −1.0. |
The default value for epss is 0.0 for the HLLE scheme, and 0.5 for the Rusanov scheme.
See Also: RHS
Last updated 6 Oct 2003