[fra_kts]

Hallo my friends ,

I am trying to simulate, in Fluent 15.0 , an oscillating airfoil, in 2D, with the following characteristics :

1)NACA 64418
2)heaving amplitude =0.05 m
3)pitching amplitude =4 degrees
4)air inlet speed =26.4 m/s (Re=0.85 * 10^6)
5)chord =0.5
6)pivot point =chord/3 (from leading edge)
7)heaving eq. of motion :h=0.05*sin(2*pi*t)
8)pitching eq. : a=1+4*sin(2*pi*t)
9)time step = 0.001 s

The turbulence model i am using is the Realizable k-e .
In order to simulate the pitch and heave motion i use sliding mesh, which is attached to the airfoil , which moves also vertically (with magnitude of motion 0.05 m) .

Mesh characteristics :
1)y+=1
2)1878 elements on airfoil
3)inflation with 30 layers and growth rate 1.2
4)170.000 elements in total



The problem i am having is that in the velocity curl contours i cant see any vortices . (see attachment)
Should there be any at this amplitudes of oscillating motion and velocity ?

In the picture you can see the velocity curl field every 0.25T of the motion .

Thank you very much in advance .

[fra_kts]

Any Help ?