| flo90000 |
June 23, 2016 10:41 |
6DOF angular acceleration
Hello
I want to simulate the movement of a valve with the 6DOF solver. This is my code:
Code:
#include "udf.h"
#include "math.h"
DEFINE_SDOF_PROPERTIES(Clapet, prop, dt, time, dtime)
{
prop[SDOF_MASS]=1.067e-7;
prop[SDOF_IZZ]=5.33e-11;
prop[SDOF_ZERO_TRANS_X]=TRUE;
prop[SDOF_ZERO_TRANS_Y]=TRUE;
prop[SDOF_ZERO_TRANS_Z]=TRUE;
prop[SDOF_ZERO_ROT_X]=TRUE;
prop[SDOF_ZERO_ROT_Y]=TRUE;
prop[SDOF_ZERO_ROT_Z]=FALSE;
prop[SDOF_LOAD_M_Z]=-9.81*0.0108*sin(DT_THETA(dt)[2])*0.0108;
Message("\n 2d : Updated 6DOF properties DT_THETA_Z:%e, Mz:%e, Mass%e\n", DT_THETA(dt)[2], prop[SDOF_LOAD_M_Z], prop [SDOF_MASS]);
}
Code:
#include "udf.h"
DEFINE_SOURCE(xmom_source,c,t,dS,eqn)
{
static real pos[ND_ND];
static real con, source, x, y;
static real X_MIN, X_MAX, Y_MIN, Y_MAX, C2;
static int i;
static Domain *domain;
C_CENTROID(pos,c,t);
x=pos[0];
y=pos[1];
X_MIN=1e-3;
X_MAX=1.16e-3;
Y_MIN=11e-3;
Y_MAX=0.01082;
C2=50000.0;
i=0;
if(x>X_MIN) i++;
if(x<X_MAX) i++;
if(y>Y_MIN) i++;
if(y<Y_MAX) i++;
if(i==4)
{
con=C2*0.5*C_R(c,t);
source=-con*fabs(C_U(c,t))*C_U(c,t);
dS[eqn]=-2.0*con*fabs(C_U(c,t));
}
else
{
source=0.0;
}
C_UDMI(c,t,0)=source;
return source;
}
DEFINE_SOURCE(ymom_source,c,t,dS,eqn)
{
static real pos[ND_ND];
static real con, source, x, y;
static real X_MIN, X_MAX, Y_MIN, Y_MAX, C2;
static int i;
static Domain *domain;
C_CENTROID(pos,c,t);
x=pos[0];
y=pos[1];
X_MIN=1e-3;
X_MAX=1.16e-3;
Y_MIN=0.01082;
Y_MAX=0.011;
C2=50000.0;
i=0;
if(x>X_MIN)i++;
if(x<X_MAX)i++;
if(y>Y_MIN)i++;
if(y<Y_MAX)i++;
if(i==4)
{
con=C2*0.5*C_R(c,t);
source=-con*fabs(C_V(c,t))*C_V(c,t);
dS[eqn]=-2.0*con*fabs(C_V(c,t));
}
else
{
source=0.0;
}
C_UDMI(c,t,0)=source;
return source;
}
I add enough UDM location and don't have some problems during the compilation. And I have this error:
Quote:
Info: 6DOF: can't compute angular acceleration.
Check moments/products of inertia.
Updating mesh at time level N...
Warning: multiple subdivision required on zone 8. Subdivide using Constant Ratio.
Error: received a fatal signal (Segmentation fault).
|
After some research I found this solution to decrease the limit of moments of inertia but it doesn't work
Quote:
(rpsetvar 'dynamesh/sdof/minimum-cutoff-moments 1e-50)
|
http://www.cfd-online.com/Forums/flu...eleration.html
So I want to know if there are other possibilities and which or/and where is my fault
Thanks for your help |
