Wind-US User's Guide - Keyword Reference, BOUNDARY-DAMP

(Wind-US Documentation Home Page) (Wind-US User's Guide) (GMAN User's Guide) (MADCAP User's Guide) (CFPOST User's Guide) (Wind-US Utilities) (Common File User's Guide) (Wind-US Installation Guide) (Wind-US Developer's Reference) (Guidelines Documents)

(Introduction) (Tutorial) (Geometry and Flow Physics Modeling) (Numerical Modeling) (Boundary Conditions) (Convergence Monitoring) (Files) (Scripts) (Parallel Processing) (Keyword Reference) (Test Options)

BOUNDARY-DAMP | BDAMP - Boundary damping (block)

Structured Grids

{BOUNDARY-DAMP | BDAMP} ZONE range1[,range2[, ... rangen]] BOUNDARY bnd1:bnd2 [POINTS n] [SECOND c2] [FOURTH c4] [NOSMOOTHING [NI m₁] [NJ m₂] [NK m₃]] {END-BOUNDARY-DAMP | ENDBDAMP}

This keyword may be used with structured grids to apply second- and fourth-order smoothing to damp waves in the vicinity of computational boundaries. It is also possible to turn off smoothing near any boundary for any numerical operator (ξ, η, or ζ). This option must be used with the SMOOTHING keyword and TEST 49 2. The user-specified values are defined as:

range

Zone specification range, in one of the following forms:

	`zonenum`		Selects zone zonenum
	`begzone:endzone`		Selects all zones from begzone to endzone
	`begzone:`		Selects all zones from begzone to `MAXZONE`, the total number of zones in the grid file
	`:endzone`		Selects all zones from 1 to endzone
	`ALL`		Selects all zones

bnd1 Starting boundary (0 to begin at boundary 1). The values 1-6 correspond to the i = 1, i = i_max, j = 1, j = j_max, k = 1, and k = k_max boundaries, respectively.

bnd2 Ending boundary (0 to end at last boundary)

n Number of points into the domain over which boundary damping is to be applied

c2 Second-order smoothing coefficient

c4 Fourth-order smoothing coefficient

The NOSMOOTHING keyword is used to turn off smoothing (as specified using the SMOOTHING keyword) for the most recently specified ZONE and BOUNDARY. The keywords NI, NJ, and/or NK specify that smoothing is to be turned off for the ξ, η, and/or ζ operator, respectively, for boundaries bnd1 through bnd2. When NOSMOOTHING is used, at least one of NI, NJ, and NK must be specified.

m₁, m₂, m₃ Number of points into the domain on boundaries bnd1 through bnd2 over which smoothing is to be turned off

Example

   BOUNDARY-DAMP
      ZONE 2:4 BOUNDARY 1:3 POINTS 15 SECOND .01 FOURTH .03
      ZONE 3:3 BOUNDARY 4:4 POINTS 10 SECOND .02 FOURTH .01
      ZONE 5:5
      BOUNDARY 2:2
      NOSMOOTHING NI 31 NJ 21
   END-BOUNDARY-DAMP

See Also: SMOOTHING, TEST 49