1 |
dgoldberg |
1.1 |
#include "CPP_OPTIONS.h" |
2 |
|
|
|
3 |
|
|
! _RL FUNCTION SLOPE_LIMITER (num, denom) |
4 |
|
|
|
5 |
|
|
_RL FUNCTION SLOPE_LIMITER (Cr) |
6 |
|
|
|
7 |
|
|
! _RL num, denom |
8 |
|
|
! _RL SLOPE_LIMITER |
9 |
|
|
! _RL r |
10 |
|
|
_RL Cr |
11 |
|
|
|
12 |
|
|
! used for flux limiting in advective subroutines |
13 |
|
|
! Van Leer limiter (source: Wikipedia!) |
14 |
|
|
|
15 |
|
|
! if (denom .eq. 0.0) then |
16 |
|
|
! SLOPE_LIMITER = 0.0 |
17 |
|
|
! elseif (num*denom .le. 0.0) then |
18 |
|
|
! SLOPE_LIMITER = 0.0 |
19 |
|
|
! else |
20 |
|
|
! r = num/denom |
21 |
|
|
! SLOPE_LIMITER = (r+abs(r))/(1+abs(r)) |
22 |
|
|
! endif |
23 |
|
|
|
24 |
|
|
SLOPE_LIMITER = max(0.D0,max(min(1.D0,2.D0*Cr), |
25 |
|
|
& min(2.D0,Cr))) |
26 |
|
|
|
27 |
|
|
|
28 |
|
|
RETURN |
29 |
|
|
END |