[Sijnhaven]

Hello,

I am simulating liquid-gas muliphase flow.

I need a UDF to define the bubble diameter for the gas phase.

I can interpret the UDF, but after initialization I get this error message:
"Node X: Process 11780: Received signal SIGSEGV"

Something is going wrong in the part of the code that is calling the properties of the primary and secondary phases.

Thank you for responding.

UDF:


#include "udf.h"


DEFINE_PROPERTY(BubbleDiameter, c, mixture_thread)
{
real BD; /* Bubble diameter */

int SurfaceTension;

int PhaseOneIndex = 0;
int PhaseTwoIndex = 1;

real DensS; /* S = primary (liquid) phase */
real DensG; /* G = secondary (gas) phase */
real XVelS;
real XVelG;
real YVelS;
real YVelG;
real ZVelS;
real ZVelG;
real EffViscG;

Thread *p1 = THREAD_SUB_THREAD(mixture_thread,PhaseOneIndex);
Thread *p2 = THREAD_SUB_THREAD(mixture_thread,PhaseTwoIndex);

DensS = C_R(c,p1); /* density liquid */
DensG = C_R(c,p2); /* density gas */
XVelS = C_U(c,p1); /* x velocity liquid */
XVelG = C_U(c,p2); /* x velocity gas */
YVelS = C_V(c,p1); /* y velocity liquid */
YVelG = C_V(c,p2); /* y velocity gas */
ZVelS = C_W(c,p1); /* z velocity liquid */
ZVelG = C_W(c,p2); /* z velocity gas */
EffViscG = C_MU_EFF(c,p1); /* effective viscosity of the gas phase */
SurfaceTension = 1.76;

BD = XXX ; /* HERE WILL BE MY FORMULA */

return BD;

}

[sikandar]

Originally Posted by Sijnhaven

Hello,

I am simulating liquid-gas muliphase flow.

I need a UDF to define the bubble diameter for the gas phase.

I can interpret the UDF, but after initialization I get this error message:
"Node X: Process 11780: Received signal SIGSEGV"

Something is going wrong in the part of the code that is calling the properties of the primary and secondary phases.

Thank you for responding.

UDF:


#include "udf.h"


DEFINE_PROPERTY(BubbleDiameter, c, mixture_thread)
{
real BD; /* Bubble diameter */

int SurfaceTension;

int PhaseOneIndex = 0;
int PhaseTwoIndex = 1;

real DensS; /* S = primary (liquid) phase */
real DensG; /* G = secondary (gas) phase */
real XVelS;
real XVelG;
real YVelS;
real YVelG;
real ZVelS;
real ZVelG;
real EffViscG;

Thread *p1 = THREAD_SUB_THREAD(mixture_thread,PhaseOneIndex);
Thread *p2 = THREAD_SUB_THREAD(mixture_thread,PhaseTwoIndex);

DensS = C_R(c,p1); /* density liquid */
DensG = C_R(c,p2); /* density gas */
XVelS = C_U(c,p1); /* x velocity liquid */
XVelG = C_U(c,p2); /* x velocity gas */
YVelS = C_V(c,p1); /* y velocity liquid */
YVelG = C_V(c,p2); /* y velocity gas */
ZVelS = C_W(c,p1); /* z velocity liquid */
ZVelG = C_W(c,p2); /* z velocity gas */
EffViscG = C_MU_EFF(c,p1); /* effective viscosity of the gas phase */
SurfaceTension = 1.76;

BD = XXX ; /* HERE WILL BE MY FORMULA */

return BD;

}

did you found the solution of this matter? Do you have UDF for terminal Velocity of bubble i need help

[Sijnhaven]

Originally Posted by sikandar

did you found the solution of this matter? Do you have UDF for terminal Velocity of bubble i need help

Yes, I believe the DEFINE_PROPERTY macro does not pass the mixture_thread, because it is coupled to the bubble diameter, which is a secondary (gas) phase property. So in this case, the DEFINE_PROPERTY macro passes the thread of the secondary phase.

The solution that I found was to first look up the mixture_thread with THREAD_SUPER_THREAD(p2), in which p2 is the thread of the secondary phase, that was passed by the solver through the DEFINE_PROPERTY macro.

Then, in a next step, I define the thread of the primary phase by using the macro THREAD_SUB_THREAD(mixture_thread,0). Of course, it is not needed to explicitly lookup the thread of the secondary phase with THREAD_SUB_THREAD(mixture_thread,1), because it was already passed to the UDF by the solver.

Unfortunately, I do not have a UDF for terminal velocity. I never used this.

Regards

[ENGRTAHIR]

Originally Posted by sikandar

did you found the solution of this matter? Do you have UDF for terminal Velocity of bubble i need help

Hi i also need help for bubble diameter. I am doing two phase simulation in fluent with combustion