26.4.2 Convective Flux Types

Three convective flux types exist when using the density-based solver:

• Roe flux-difference splitting (Roe-FDS)

• Advection Upstream Splitting Method (AUSM)

• Low diffusion Roe flux-difference splitting (Low Diffusion Roe-FDS)

Roe-FDS splits the fluxes in a manor that is consistent with their corresponding flux method eigenvalues. It is the default and is recommended for most cases.

AUSM provides exact resolution of contact and shock discontinuities and it is less susceptible to Carbuncle phenomena.

Low diffusion Roe-FDS is used when the LES viscous model is enabled. It reduces the dissipation in LES calculations and is used only for subsonic flows.

User Inputs

The convective fluxes are selected from the Flux Type drop-down list in the Solution Methods task page (Figure  26.4.1).

Solve $\rightarrow$ Controls $\rightarrow$ Solution...

Select Roe-FDS, AUSM, or if the LES viscous model is enabled, Low Diffusion Roe-FDS.