[mperrin]

Dear users, hello !

I work on a simulation and request your help.


You can see my geometry in attachments. I am working on a thermal exchange between a solid zone (SOLID on the figure) and a fluid zone (FLUID1, 2 & 3). The flow is generated by a synchros move of boundaries (WALL A) and (WALL B).
The problem i encounter is generated by the interface between (SOLID) and (FLUID 2) area :
- when i assign and classic interface between the two zone, fluent returns me a SIGSEGV error
- when i change this interface for a wall (so there is no longer heat echant because the solid become totally insulated), the calcul run perfectly.


I suspect that i have to define additional zone but i am not sure. As SIGSEGV error generally comes in with UDF error, i request your help !


Here there is my code, the move i want to do is a simple sinusoidal signal.

#include"udf.h"
#include"mem.h"
#include"math.h"

double TimeStepSize = 0.01f;
double lenght = 0.045f;
double alpha = 0.56f;
double frequency = 0.5f;
double Vmax = 0.f;

static real velx = 0.0;
double Omega;

DEFINE_CG_MOTION(Piston, dt, vel, omega, time, dtime)
{
    NV_S(vel, =, 0.0);
    NV_S(omega, =, 0.0);

    Vmax = alpha * M_PI * frequency * lenght;
    Omega = 2 * M_PI * frequency;

    velx = (Vmax / Omega) * (cos(Omega * (time - TimeStepSize)) - cos(Omega * time)) / TimeStepSize;

    vel[0] = velx;
}

Do i have to define more zone in dynamich mesh setup like static zone ?
Do i have to make a static define motion UDF and assign it somewhere ?
Is there any error in my UDF ?


Thank you for reading and for your time !

Happy New Year !!