Problem with airflow over naca0012 and angle o f attack
I'm working on a comparison between FA and CFX with some airfoils. I'm working with laminar flow Reynolds number of 360,000 for naca 0012. CFX simulates the data as followed. Now I'm trying to simulate in the OF, but the values of Cd and Cl are very different from those obtained in CFX and literature, and an angle of attack of 2 degrees the pressure field is completely irregular, I'm changing the angle of attack from speed change. Attached is the photo of the pressure field and cases.
with a Reynolds number of 360,000 the flow is expected to be turbulent, not laminar! A turbulence model would be appropriate to improve the numerical results, especially drag.
Another thing: the freestream boundaries are much too close to the airfoil surface. The distance between airfoil and farfield boundaries should be at least 20 cord lengths! Otherwise the flow close to the airfoil surface is distorted by the farfield boundary conditions and the results are negatively affected.
thanks for your reply.
I was wondering, why this problem did not show up in CFX, OF is much more sensitive than CFX? Because the pressure field for an 3º is completely different from the 2º.
Other thing i am not sure if my case is set up correctly, now i am trying to
use the airfoild2d tutorial case, can you help me with the reference length and area for that airfoil.
|All times are GMT -4. The time now is 05:39.|