Changes between Version 3 and Version 4 of doc/tec/topography

Timestamp:

Aug 12, 2016 10:00:03 AM (9 years ago)

Author:

suehring

Comment:

--

doc/tec/topography

@@ -20 +20 @@
 }}}
 The additional topography code is executed in regions B and C only. As the velocity components are defined on a different (staggered) grid
-than the scalar quantities (see Fig. 1 in Sect. [wiki:doc/tec/discret discretization]), three extra pairs of 2-D height index arrays are defined; two for the horizontal velocities and one for scalar quantities (e.g., '''''nzb_s_inner''''' and '''''nzb_s_outer''''' for scalar quantities).
+than the scalar quantities (see Fig. 1 in Sect. [wiki:doc/tec/discret discretization]), three extra pairs of 2-D height index arrays are defined; two for the horizontal velocities and one for scalar quantities (e.g., '''''nzb_s_inner''''' and '''''nzb_s_outer''''' for scalar quantities). \\\\
+
+'''Treatment of holes''' \\
+
+In case there are holes in the topography that are resolved by only one grid point, the topography array in filtered so that such holes are filled up to the minimum topography height of the directly adjoining grid points in the x- and the y-direction. This is necessary, because for such chimney-like features resolved by one grid point, the continuity equation is not fulfilled on a discrete grid, as the only degree of freedom for the pressure solver is the vertical. Such holes are suspected to lead to unrealistic velocity blow-ups, hence, they are filled up.