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2D airfoil with heaving and pitching motion

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Old   February 26, 2014, 09:58
Question 2D airfoil with heaving and pitching motion
  #1
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He Zhao
Join Date: Feb 2013
Location: Shanghai(now)
Posts: 11
Rep Power: 4
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Hi friends,
Now I'm dong a research.It's about 2D airfoil with heaving and pitching motion. I want to use sliding meshes.
the pitching motion is that the airfoil revolve around an axis (the axis is in A quarter of the chord length)
the heaving motion is that the airfoil oscillate in the y direction(2D).
velocity[1]=0.5*3.14159265*cos(0.2*3.14159265*time)


my udf is this:


#include "udf.h"
DEFINE_ZONE_MOTION(fmotion,omega,axis,origin,veloc ity,time,dtime)
{
real omegar;
velocity[0]=0.0,velocity[1]=0.5*3.14159265*cos(0.2*3.14159265*time),velocity[2]=0.0;

origin[0]=0.0, origin[1]=time*velocity[1], origin[2]=0.0;
omegar = 0.5*3.14159265*cos(0.2*3.14159265*time);
*omega = omegar;

return;
}



I think "heaving motion" is
velocity[1]=0.5*3.14159265*cos(0.2*3.14159265*time)
and "pitching motion" is
origin[0]=0.0, origin[1]=time*velocity[1], origin[2]=0.0;
omegar = 0.5*3.14159265*cos(0.2*3.14159265*time);

I know it's wrong,But I don't know how to simulate the two motion together.

best regards,
zhereal

Last edited by zhereal; February 26, 2014 at 10:31. Reason: an unbalanced view
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Old   April 13, 2014, 15:18
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  #2
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He Zhao
Join Date: Feb 2013
Location: Shanghai(now)
Posts: 11
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zhereal is on a distinguished road
I solve this problem.
the udf is below:

#include "udf.h"
DEFINE_ZONE_MOTION(gustn11,omega,axis,origin,veloc ity,time,dtime)
{
real m,n;
m=-292.286;
n=0.2046*sin(m*time);
velocity[0]=0.0,velocity[1]=n,velocity[2]=0.0;
origin[0]=0.0,origin[1]=0.0,origin[2]=0.0;
axis[0]=0.0,axis[1]=1.0,axis[2]=0.0;
*omega=m;
}
#include "udf.h"
DEFINE_ZONE_MOTION(zgustkz,omega,axis,origin,veloc ity,time,dtime)
{
real a,b,c,d,e,f,g,h,i,j,k,l;
a=20.46;
b=-292.286;
c=292.286;
d=0.01745;
e=3.14159;
f=0.2046*sin(b*time);
g=0.01*a/b;
h=g+(-1)*g*cos(b*time);
i=d*b*cos(b*time+e);
j=sqrt(i*i+b*b);
k=sin(c*time);
l=cos(c*time);
velocity[0]=0.0,velocity[1]=f,velocity[2]=0.0;
origin[0]=0.0,origin[1]=h,origin[2]=0.0;
axis[0]=((-1)*k*i)/j,axis[1]=b/j,axis[2]=(l*i)/j;
*omega=j;
}
#include "udf.h"
DEFINE_ZONE_MOTION(fgustkz,omega,axis,origin,veloc ity,time,dtime)
{
real a,b,c,d,e,f,g,h,i,j,k,l;
a=20.46;
b=-292.286;
c=292.286;
d=0.01745;
e=3.14159;
f=0.2046*sin(b*time);
g=0.01*a/b;
h=g+(-1)*g*cos(b*time);
i=d*b*cos(b*time+e);
j=sqrt(i*i+b*b);
k=sin(c*time);
l=cos(c*time);
velocity[0]=0.0,velocity[1]=f,velocity[2]=0.0;
origin[0]=0.0,origin[1]=h,origin[2]=0.0;
axis[0]=(k*i)/j,axis[1]=b/j,axis[2]=((-1)*l*i)/j;
*omega=j;
}
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