Velocity of 3.5 for oscillating airfoil - logical?

quarkz

Hi,

I am simulating flow past an oscillating airfoil. It is oscillating up/down with a sin function ie y=sin(t). vel y, v=cos(t), hence, max v=1. Inlet velocity is u=1.

However, near the front top end of the airfoil, where a vortex is formed, I have velocity vectors as large as 3.5.

Is this logical? Hope someone can give some advice.

Thank you very much