[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

*To*: "Stephan Kohler" <skohler@xxxxxxxxxxxxxxxx>*Subject*: Re: modelling a stirred tank reactor*From*: "David L Parkhurst" <dlpark@xxxxxxxx>*Date*: Fri, 29 Nov 2002 09:55:13 -0700*Bcc*: "David L Parkhurst" <dlpark@xxxxxxxx>*In-reply-to*: <NFBBJJDGMKMNCIJGJPOJOEEDCFAA.skohler@lmtg.ups-tlse.fr>

> Now are there more elegant ways to do it ? I've included an input file that performs a mixing calculation. I think it is close to what you want to do if you add the kinetic reaction. In the setup, solution 3 mixes with solution 1 in a two-cell transport calculation. It uses two cells because the minimum number of cells in a column for TRANSPORT is two, but calculations for cell 2 are ignored. For the transport calculation, there is no flow (flow_direction diffusion_only) and boundary conditions closed. A single stagnant cell is defined for each cell of the column; this allows explicit mixing factors to be defined for each cell. The mixing characteristics of cell 1 are defined explicitly by MIX 1, in this case .9 of solution 1 remains and .1 of solution 3 is added at each shift (mix). The composition of solution 3 does not change. The number of mixes is determined by the number of "shifts" in the transport calculation. You can run a transport calculation for a number of shifts, then redefine solution 3, and define another transport calculation to simulate a change in the feed to the reactor. Adding a definition for KINETICS 1 (and RATES and appropriate time_step in TRANSPORT) will include a kinetic reaction for cell 1. Similarly, you can add EQUILIBRIUM_PHASES 1, SURFACE 1, EXCHANGE 1, or SOLID_SOLUTIONS 1 to include those processes in the reactor. The example runs two mixes and the amount of bromide initially present in cell 1 decreases from 1 to .9 to .81 in the successive shifts in accordance with the mixing fraction of .9 of the solution remains and no additional Br is added. > How can I define a new solution from previously stored parameters OUTSIDE a rate function ? Hopefully you do not have to do this. It is probably possible to use clever definitions of another stagnant cell to save a solution. It is probably also possible to define a series of kinetic reactions, each of which adds back a saved quantity for a single element. > Can one make a DO LOOP to group a MIX and RATE function No, I've thought about it, but never got around to coding it. David solution 0-4 Na 1 Cl 1 end solution 1-2 K 1 Br 1 end MIX 1 3 .1 1 .9 END KINETICS 1 .... TRANSPORT -cells 2 -shifts 2 -time_step 1 # seconds -flow_direction diffusion_only -boundary_conditions closed closed -stagnant 1 0 0 0 -print_cells 1 -punch_cells 1 -warnings true END David Parkhurst (dlpark@xxxxxxxx) U.S. Geological Survey Box 25046, MS 413 Denver Federal Center Denver, CO 80225 Project web page: https://wwwbrr.cr.usgs.gov/projects/GWC_coupled

**References**:**modelling a stirred tank reactor***From:*Stephan Kohler

- Prev by Date:
**modelling a stirred tank reactor** - Next by Date:
**Re: Modelling saine environments** - Previous by thread:
**modelling a stirred tank reactor** - Next by thread:
**Re: Modelling saine environments** - Index(es):

Project Home Page

Complete Water Resources Division Software

USGS Home Page

Water Resources Division Home Page

NRP Home Page

Help Page

Please note that some U.S. Geological Survey (USGS) information accessed through this page may be preliminary in nature and presented prior to final review and approval by the Director of the USGS. This information is provided with the understanding that it is not guaranteed to be correct or complete and conclusions drawn from such information are the sole responsibility of the user.

Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government.

The URL of this page is:
https://wwwbrr.cr.usgs.gov/projects/GWC_coupled/phreeqc/mail/msg00112.html

Email:dlpark@usgs.gov

Last modified: $Date: 2005-09-13 21:04:21 -0600 (Tue, 13 Sep 2005) $

Visitor number 2257 since Jan 22, 1998.