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Lift Coefficient on 2D Airfoil

Question asked by Josiah Lund on Feb 12, 2015
Latest reply on Apr 7, 2015 by Josiah Lund

I've been working with a model trying to calculate the lift coefficient on a 2D section of a HM60 airfoil. Data for the airfoil can be found here. The airfoil is 1 ft in length in flow at 150 ft/s giving a Reynolds number of ~950,000. I have done my own XFLR5 (based on Xfoil) simulation on the airfoil to confirm the data found on the website and my results are in agreement. I zoomed in much further and Cl is about 0.0788


Cl v Alpha.PNG


On the SolidWorks side, I have set up a 2D flow simulation with air at a velocity 150 ft/s and density of 1.225 kg/m^3 (0.002377 slug/ft^3). Air properties are standard properties of air referenced from table in some of my classroom textbooks. These are the same values that are used in XFLR5.

Initial Conditions.PNG

The domain I left the automatic size as it seemed sufficiently large.


The lift coefficient was calculated as follows using the global Y force as the lift.

Cl Equation.PNG

The mesh was created using the highest level automatic mesh with a local mesh with a level 1 overall refine. In the control conditions, the refine level was set to 4 with an approximate max number of cells set to 10,000,000. To my understanding, it only refined the mesh twice. The final mesh is shown below.

Total Domain.PNGLocal Initial Mesh.PNGAirfoil Refinement.PNGSurface Precision.PNG


And now the results. The jump at the beginning was due to me having the Cl equation off. There were approximately 312,000 fluid cells with 16,000 partial cells. The coefficient sat right around 0.07.



I realize that my calculation is not fully converged, but it did not seem to be going anywhere, so I stopped it.


Can anybody advise me on how to get a little more agreement between my calculated value of ~0.07 and what I believe is the more accurate and true ~0.08, or is this as close as I can hope to get?