DGF
Interval
0 0   % first corner 
1.5 0.74   % second corner
44 24   % 22 cells in x and 12 in y direction
# 
GridParameter
overlap 0 
periodic 
closure green
#GridParameter 
BOUNDARYDOMAIN
default 1    % all boundaries have id 1
#BOUNDARYDOMAIN
# unitcube.dgf