[fluent_cfd]

I am trying to calculate the oscillatory shear index using an UDF. However, when I switch from single phase to multiphase the UDF gives me SIGSEGV errors. The first UDF is:

/* Initialize the UDM value to zero in complete domain */
DEFINE_INIT(meminit,domain)
{
Thread *c_thread;
cell_t c;

thread_loop_c(c_thread,domain)
{
begin_c_loop(c, c_thread)
{
C_UDMI(c,c_thread,0)= 0;
C_UDMI(c,c_thread,1)= 0;
C_UDMI(c,c_thread,2)= 0;
C_UDMI(c,c_thread,3)= 0;
C_UDMI(c,c_thread,4)= 0;
}
end_c_loop(c, c_thread)
}
}

Which I adjusted to:

DEFINE_ON_DEMAND(meminit)
{
Thread **pt;
Thread *c_thread;
cell_t c;
Domain *d;
d = Get_Domain(domain_ID);

mp_thread_loop_c(c_thread,d,pt)
{
begin_c_loop(c,c_thread)
{
C_UDMI(c,c_thread,0)= 0;
C_UDMI(c,c_thread,1)= 0;
C_UDMI(c,c_thread,2)= 0;
C_UDMI(c,c_thread,3)= 0;
C_UDMI(c,c_thread,4)= 0;
}
end_c_loop(c, c_thread)
}
}

This seems to work (at least it does not give me errors anymore). The adjustment of thread_loop_c to mp_thread_loop_c was the fix. But if I try to do the same for the second UDF, it keeps giving me errors. Does anyone have an idea how I should adjust this UDF to prevent errors in multiphase flow? Thank you!

/* Calculate wall shear stress and store them in UDM */
DEFINE_EXECUTE_AT_END(OSI)
{
Domain *domain;
real area;
face_t f;
real A[ND_ND];
cell_t c, c0;
Thread *t,*t0, *c_thread;
real wallshear [ND_ND];

domain = Get_Domain(domain_ID);
t = Lookup_Thread(domain,zone_ID);

begin_f_loop(f, t)
{
F_AREA(A,f,t);
area = NV_MAG(A);
NV_V(wallshear,=,F_STORAGE_R_N3V(f,t, SV_WALL_SHEAR));
c0 = F_C0(f,t);
t0 = THREAD_T0(t);
C_UDMI(c0,t0,0) += NV_MAG(wallshear)/area;
C_UDMI(c0,t0,1) += -wallshear[0]/area;
C_UDMI(c0,t0,2) += -wallshear[1]/area;
C_UDMI(c0,t0,3) += -wallshear[2]/area;
C_UDMI(c0,t0,4) = (1.-sqrt(C_UDMI(c0,t0,1)*C_UDMI(c0,t0,1) + C_UDMI(c0,t0,2)*C_UDMI(c0,t0,2) + C_UDMI(c0,t0,3)*C_UDMI(c0,t0,3))/C_UDMI(c0,t0,0))/2;
}
end_f_loop(f,t)
}