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Sandilya Garimella February 20, 2008 10:37

DPM #include "filename" ?
Hello everyone I am using a DPM model and using the macro

C_UDMS_CONCENTRATION to extract cell dpm concentarion However, when I compile I get the follwoing error

error LNK2001: unresolved external symbol _C_UDM_CONCENTRATION

which, from what I understand, essentially means that I have not included all the necessary header files. But I have includeed in my code udf.h and dpm.h files Still this problem persists

Can anyone tell me what is the header file to be included for C_UDMS_CONCENTRATION macro?

Thank you


RE13 February 20, 2008 14:00

Re: DPM #include "filename" ?
I searched all of the header files available in the Fluent src directory and could not find any C_UDMS string matches. Where did you find this macro? "C_UDMI" is located in mem.h, you can try including that header file.

Good luck


Sandilya Garimella February 20, 2008 14:03

Re: DPM #include "filename" ?
Thank you for your response i found this macro in the fluent forums archives as macro for extracting cell dpm concentrations

I too searched but did not find reference to it but I am trying to use this macro because it seems to work as other users have said

thank you

Regards Sandilya

RE13 February 20, 2008 14:04

Re: DPM #include "filename" ?
also try sg_mem.h

Sandilya Garimella February 20, 2008 14:07

Re: DPM #include "filename" ?
And I included mem.h in my code but it still does not work

RE13 February 20, 2008 14:21

Re: DPM #include "filename" ?
you have been misinformed, the correct macro is C_DPMS_CONCENTRATION(c,t) and it is located in sg_mem.h

Sandilya Garimella February 20, 2008 14:33

Re: DPM #include "filename" ?
Thank you very much. That was very helpful.

However, I have another question

Can you please tell me if the following code has syntax errors in it? I am tracking droplets which have single charge on them In each cell i am trying to get the total charge due to all particles by looping over all particles in a cell and then adding the charges. This I am doing because later on I want to assign a charge distribution on droplets based on their diameters.

But when I hook the adjust udf given below, fluent displays error On inspection i found that due to error c-uDMI(c,t,3) variable is not updated after the iterations before error while the earlier memory variables 0,1,2 are updated

Hence the error is just above the UDM 3 in the code Can you tell me if my looping over all particles in the cell as shown below is syntactically wrong?

DEFINE_ADJUST(electric_field, d) { Thread *t,*tf; cell_t c; face_t f; double pc[ND_ND];

double mp; /* mass of particle */ int Z; /* charge state of particle */ double M;

Particle *pi;

thread_loop_c(t, d) {





begin_c_loop_all (c,t)


C_UDMI(c,t,0) = -C_UDSI_G(c,t,0)[0]; /* [V/m] Ex */

C_UDMI(c,t,1) = -C_UDSI_G(c,t,0)[1]; /* [V/m] Ey */

C_UDMI(c,t,2) = NV_MAG(C_UDSI_G(c,t,0)); /* [V/m] E */



/* Loop over particles in cell*/



/*For each particle Z and m is extracted*/

/*M = Summation of masses of all charges*/

/* M += pi->state.mass; */

/* Summation of charges - alll are unit charges*/

Z = Z + 1;

} end_particle_cell_loop(pi,c,t)

C_UDMI(c,t,3) = (1/C_VOLUME(c,t)) * ((double)Z * qe); /* [Cu/m^3] rhoe */

C_UDMI(c,t,4) = C_UDMI(c,t,3)*C_UDMI(c,t,0); /* [N/m^3] Fx */

C_UDMI(c,t,5) = C_UDMI(c,t,3)*C_UDMI(c,t,1); /* [N/m^3] Fy */


end_c_loop_all (c,t)

} } }

RE13 February 20, 2008 16:14

Re: DPM #include "filename" ?
can you provide the error message you are getting?

Sandilya Garimella February 20, 2008 16:28

Re: DPM #include "filename" ?
when I hook the DEFINE_ADJUST and start the simulation I get the following error

Error: FLUENT received fatal signal (ACCESS_VIOLATION) 1. Note exact events leading to error. 2. Save case/data under new name. 3. Exit program and restart to continue. 4. Report error to your distributor. Error Object: ()

RE13 February 21, 2008 12:30

Re: DPM #include "filename" ?
Sorry, I can't see anything wrong with your UDF, however I know that an Access violation would not be a consequence of incorrect syntax. I think the problem is that you are trying to access particle data with the Define Adjust macro wich does not have any pointer to a tracked particle passed to it. I would try to redesign the UDF with on the model-specific discrete phase macros such as DEFINE_DPM_SCALAR_UPDATE..



lig February 4, 2010 01:01

Code of Concentration in each cell
Could you please help me in similar problem?

I inject particles using UDF of Scalars. I need to get the particle concentration in each cell. But I need one-way coupling for particle and air, so I can not check the "Interaction with continuous phase". Then C_DPMS_CONCENTRATION(c,t) won't work. Is there C_CONCENTRATION(c,t) or similar code that I can use. I have to get the concentration code, because it is needed in the function of source term.

Thanks for taking your time!

Originally Posted by RE13
also try sg_mem.h

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