Learning Forum

[basbas34]

Hi,

I'm trying to model changing density of a particle during its residence inside the dryer. I tried to make a udf for chaning density, but ended up with a changing density of my inlet of particles (see UDF below). I'm using a DPM model with a viscous rng k-e model. I was wondering if someone could give me clue how to change my code to specify it to the particle during residence instead to the inlet?

#include "udf.h"

DEFINE DPM SCALAR UPDATE(name,c,t,initialize,p)

{

real rho;

real flow_time = RP_Get_Real("flow-time");

if (flow_time < 12)

rho = rho = 42.87*exp(-1.525*flow_time)+486.2*exp(-0.2367*flow_time); 

else

rho = 42.87*exp(-1.525*12)+486.2*exp(-0.2367*12);

return (rho);

}

[Rob]

You're linking the density to the solver time, you need to look for the residence time. Try using TP_TIME(tp) https://ansyshelp.ansys.com/account/Secured?returnurl=/Views/Secured/corp/v211/en/flu_udf/flu_udf_sec_define_dpm_scalar_update.html instead. I've not checked the macro so feed back if it works (or not).

[basbas34]

i tried to open the link but can't due to student licensing

[Rob]

/forum/index.php?p=/discussion/22563/using-help-with-links