07/00
TABS-MDS
WM CARD
FALL VELOCITY FUNCTION
WM CARD
See the note below for an explanation of how this card is applied.
Field
Variable
Value
Description
0,C1-2
IC1
WF
Card group identifier
1
IGS
+
Sediment grain size
2
SRF2(IGS)
0,+
Concentration threshold 2
Default = 10.0 kg/m3
3
WSPOW(IGS)
+
Settling exponent.
NOTE: At high enough sediment concentrations, the settling rates of cohesive
sediments are observed to be a function of the concentration in the
water column. This card allows the user to define 2 threshold concentration values that are used to generate
a fall velocity function which depends on the sediment concentration (STLRGM1 AND STLRGM2). The
expression for this function is given below:
IF STLRGM1 ≥ C
WS(GS) = WHO(GS)*(SLTRGM1/SRF2)WSPOW
IF SRF2 ≥ C > STLRGM1
WS(GS) = WHO(GS) (C/SRF2)WSPOW
IF C > SRF2
WS(GS) = WHO(GS)
Where SRF2 and WSPOW are weighted averages (by sediment fraction) of
the values of these parameters for all grain sizes.
61
Previous Page
