TVD [OFF | FACTOR factor | MINMOD [factor] | KOREN [factor] | ALBADA] \ [zone_selector] |
TVD [OFF | FACTOR factor | MINMOD [factor] | SUPERBEE factor | \ BARTH-JESPERSEN [factor [CELL|FACE] [SCALAR|DIRECTIONAL]] | \ VENKAT [factor [KVENKAT KVenk]] ] \ [zone_selector] |
For structured grids, this keyword controls the TVD flux limiter in the explicit operator, which is helpful in preventing overshoots in flowfield properties in regions of high gradients. TVD may be used with the Coakley, Roe, Van Leer, HLLC, HLLE, and Rusanov explicit schemes. TVD is enabled by default for these schemes, using the standard minmod TVD limiter with the default compression parameter, and disabled for all others.
OFF | Disables TVD for the specified zone(s)
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FACTOR | Use the standard minmod TVD limiter.
The value of factor specifies the "compression" parameter
for the TVD algorithm, which controls the amount of limiting applied.
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MINMOD | Use the standard minmod TVD limiter.
This is the same as FACTOR, except that the factor
may be defaulted.
The value of factor specifies the "compression" parameter
for the TVD algorithm, which controls the amount of limiting applied.
The default compression parameter is the maximum value which
assures TVD properties for the explicit operator being used
(as specified by the RHS keyword).
The default values are shown in the following table for the
various versions of the explicit differencing scheme.
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KOREN | Use the Koren TVD limiter.
With this limiter, the default value of factor is 1.0, and
does not depend on the explicit operator being used.
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ALBADA | Use the van Albada TVD limiter. With this limiter, no factor value is input. |
If TVD flux limiting is turned on for an invalid explicit scheme, but without specifying a compression parameter, TVD flux limiting will automatically be disabled and the run will continue. Otherwise, an error message is generated and the run will abort.
See Also: BOUNDARY TVD, RHS
For unstructured grids, the Barth-Jespersen slope limiting method is the default. Various other options are available.
OFF | Disables slope limiting for the specified zone(s)
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FACTOR | Use the standard slope limiting procedure.
The value of factor specifies the slope limiting parameter,
and must be specified.
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MINMOD | Use the standard slope limiting procedure.
This is the same as FACTOR, except that the factor
may be defaulted.
The default slope limiting parameter is 0.0 for first-order
spatial differencing, and 3.0 for second-order differencing.
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SUPERBEE | Use "super-bee" slope limiting.
The slope limiting parameter factor must be specified.
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BARTH-JESPERSEN | Use Barth-Jespersen slope limiting.
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VENKAT | Use Venkatakrishnan slope limiting.
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See Also: CONVERGE LOAD, RHS, DEBUG 64
Last updated 1 Apr 2016