cngf-pf

commit a91a9d97e214821989e66263c3de85574dc6871e
parent 04d61fb2168220e586ba0859a554124f98b6d842
Author: Anders Damsgaard <anders@adamsgaard.dk>
Date:   Tue, 26 Jan 2021 15:30:08 +0100

cngf-pf.1: add note on overridden permeability values in transient simulations

Diffstat:
M
cngf-pf.1
 | 
7
++++++-

1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/cngf-pf.1 b/cngf-pf.1
@@ -123,7 +123,12 @@ Factor relating dilatancy angle to the volume fraction [-] (default
 Darcian intrinsic permeability of granular material [m^2] (default
 1.9e-15).
 Only relevant with fluid dynamics enabled
-.Fl ( F ) .
+.Fl ( F ) ,
+and without transient dynamics.
+In transient simulations
+.Fl ( T )
+the permeability value is overridden by the Kozeny-Carman relationship
+(k = d^2/180 * phi^3 * (1 - phi)).
 .It Fl L Ar length
 Simulation domain length [m] (default 1).
 .It Fl l Ar applied-shear-vel-limit