GRID LIMITER {ANGLE angle | OFF} [zone_selector] |
Wind-US's grid limiting capability switches the explicit operator to a first-order scheme in the presence of grid turning greater than a specified amount. This capability may be needed to reduce numerical instabilities near wing tips, leading edges, and other geometric features which may require extreme amounts of grid turning.
The parameter angle is the number of degrees off of a straight line allowed before limiting the scheme to first-order accuracy.
This keyword applies to most of the first-, second-, and third-order explicit operators available with the RHS keyword. It does not apply to the CENTRAL and COAKLEY schemes (but see TEST 139 for COAKLEY). It also does not apply to first-order upwind schemes, and may not be used with third-order fully upwind, fourth-order, or fifth-order schemes.
The default for structured grids is OFF.
The default for unstructured grids is 150 degrees.
See Also: RHS, TVD, DEBUG 81, TEST 110, TEST 139
Last updated 1 Apr 2016