Hi D3D-Delwaq community,
could you tell me, in which subroutine is the concentration (CONC)
computed? In processes (waq_process) the CONC is a substance and other
processes will be calculated through concentration. But which
subroutin does compute the CONC? it comes from AD-transport equation.
But which subroutine in waq_kernel is the transport equation for amass
Dear Delwaq users, I found the answer :). It is
considered in trase2.f (line 200-Downward advection) in waq_process.
The strategy in DELWAQ is to compute the mass balance - everything is
converted to mass fluxes, these are summed and then the concentration
is calculated from the mass and the volume. This necessarily differs
per integration option. I fyou want to know the details, have a look
in the routines dlwqn* - these are the main routines for each
Thanks Arjen. In sedim.f, the sedimentation flux (line 179,180 and
338) is calculated from CONC results. But how sedimentation flux will
change the CONC?
That is done i the very same way as all other fluxes: DELWAQ keeps
track of the influence a particular flux has on a substance via a
table of "stoichiometric" coefficients. For suspended
sediment two fluxes are important: a flux from the water phase to the
bottom material and the vertical transport (sinking of the material).
Both are stored in the PMSA array, but have a different character -
determined by the process definition. The exchange of material from
the water phase to the bottom is a regular flux and represented by two
dMwater/dt = - sedimentation flux
dMbottom/dt = + sedimentation flux
(Note: M is the mass in the segment)
For the sinking the flux as calculated is interpreted as a "flow
velocity" on top of the flow prescribed by the hydrodynamics.