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bug in phreeqc.cvode?



Hi David,
I found some strange thing when running the transport model, i.e., sometime the selected output file is empty. 
Don't know if it is a bug.
Look at the small example below, the output fild tmp1 is empty after running in my computer.  
cheers,
xiaomin                              

TITLE Test

SOLUTION 1-28  
  pH 7   charge
  units mol/kgw
  pe 4
  -water 0.03375 
  Na 1e-3
  Cl  2.9e-03 
end

SOLUTION 0  Inlet concentration
  pH 7    
  units mol/kgw
  pe 4
  -water 0.03375  
end

TRANSPORT
  -cells 28
  -shifts  50 
  -time_step 30857  #10.5d/28*86400s/d
  -flow_direction forward
  -lengths 28*5e-3 
  -boundary_conditions flux flux
  -dispersivities 28*0.012
  -correct_disp true
  -diffusion_coefficient 0.0000 
  -punch_cells 28
  -punch_frequency 1 
  -warnings false

SELECTED_OUTPUT
  -file tmp1
  -selected_out true
  -user_punch true
  -reset false

PRINT
  -reset false
  -selected_output true
  -status true

USER_Graph
  -start 
5   pv=STEP_NO/28
145  ph=-log10(ACT("H+"))
160  PUNCH pv,ph,"1"
 -end

END
	


======= At 2003-06-26, 07:17:00 you wrote: =======

>I have been working on a method for integrating the rate equations that
>works better with stiff equations. I have implemented a package called
>CVODE from Lawrence Livermore National Lab as an alternative to the
>Runge-Kutta method that should speed up the calculations. This version
>should work better when you are trying to simulate equilibrium by using
>fast rates, which is the situation in the problem you sent me earlier. You
>should be able to use the enclosed version without having to increase the
>rate constants to be on the order of the time step. I have done some
>preliminary testing and the program seems to work, but you should do some
>additional testing to make sure it is working correctly on your problems.
>The enclosed program has identical functionality to PHREEQC, except this
>version uses CVODE to integrate rate expressions, which could be slower
>than RK in some (many?) cases. Please let me know if you find any bugs and,
>if you use it, whether it works satisfactorily.
>
>David
>
>(See attached file: phreeqc.cvode.exe)
>
>
>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

= = = = = = = = = = = = = = = = = = = =
			

Best regards.				 
xiaomin Mao
Institute for Infrastructure and Environment
School of Engineering and Electronics
The University of Edinburgh
Crew Building
King's Buildings
Edinburgh EH9 3JN
United Kingdom

Tel:  +44 131 650 5810
Fax: +44 131 667 9238
xmao@xxxxxxxxxxxxxxxxxx
http://myprofile.cos.com/maoxm

2003-07-01





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