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Species mass fraction in each cell

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Old   September 15, 2005, 10:21
Default Species mass fraction in each cell
  #1
Mohan R
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Dear all, I am solving gas-liquid phase (two-fluid model) in bubble column reactor.Liquid is continuum phase and i added a tracer(species) in the liquid phase itself. I want to calculate mass fraction of tracer in all the individual cells.So written a DEFINE ADJUST udf to calculate the mass fraction in the individual cell using C_YI(c,t,i)

mp_thread_loop_c(cell_threads, mixture_domain, pt) {

begin_c_loop(cell,cell_threads)

{

tcr= C_YI(cell,cell_threads,0)

............

.............

}end_c_loop(cell,cell_threads) }

After i hook the UDF i get an error: Error: FLUENT received fatal signal (ACCESS_VIOLATION)

Please help me to workaround for the problem. Mohan

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Old   September 16, 2005, 06:47
Default Re: Species mass fraction in each cell
  #2
Giordano Bruno
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Maybe in your Fluent's version you can't use species transport option and two-phase model...which is your version???I'm working with 6.1.22 and when I try to use a two-phase model the Species Transport Option is not available...

Regards,

Giordano Bruno
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Old   September 16, 2005, 06:52
Default Re: Species mass fraction in each cell
  #3
Mohan R
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I am using Fluent 6.2.16 version, which has the facility for the species transport in multiphase system.

any workaround for me, thanking you in advance

Mohan
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Old   September 29, 2005, 10:21
Default Re: Species mass fraction in each cell
  #4
RoM
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Access violations often indicate that you are trying to access data, where no data exist. Looking at your udf we will find the error in you second loop. From fluents point of view, a cell with mutiple phases holds 2 kind of data. Data that are shared by all phases are stored at the main cell level and can be accessed with the cell_threads pointer. Other data are phase specific and therefore NOT stored at the main cell level. They are stored in sub level threads with one thread for each phase. Sub level threads can be accessed with the pt pointer array, e.g. pt[2] would return then pointer to the sub level thread for the phase with index 2. Lets assume your liquid phase index is 2 then your udf should look like this

mp_thread_loop_c(cell_threads, mixture_domain, pt) {

begin_c_loop(cell,pt[2])

{

tcr= C_YI(cell,pt[2],0)

............

.............

}end_c_loop(cell,pt[2]) }

Good luck

RoM
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Old   October 4, 2005, 01:50
Default Re: Species mass fraction in each cell
  #5
Mohan R
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Thanx a lot RoM, the solution suggested by you is working.

With regards, Mohan

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