Moment Coefficients from ADflow not matching with actual value

[vishnu67sankar]

Hello there!

I was running a 2D airfoil analysis based on the test case02 from the "AIAA Aerodynamic Design Optimization Discussion Group". The results for which are available in the paper here, as published by the authors, on page number 14, table 7. I generated a mesh using pyHyp, and ran the analysis in ADflow. The Cl and Cd values I got are about 0.8708 and 222.2 counts respectively, which are roughly quite close to the values given in the paper above. However, the moment coefficient I got from ADflow is way off. I have attached the output file below which monitors the residuals, Cd, Cl, and Cm values throughout the simulation. For completeness, the output contains the moment coefficient about the X, Y and Z axis. But none of them is close to the actual value (~ -0.0948). I have checked the orientation of my airfoil, it is in the XY plane with the chord lying along the X-axis. I have uploaded the mesh and other required files here incase anyone wants to have a look at it.

Does anyone know what's going on with the moment coefficient calculation? Am I missing something here?

output_analysis.txt
adflow_parameters.txt

[eirikurj]

Hey, for the aeroproblem, did you set the reference point, i.e., xRef? See https://mdolab-baseclasses.readthedocs-hosted.com/en/latest/pyAero_problem.html for details.

[vishnu67sankar]

Hey! Thanks for the catch, I had used xref instead of xRef, no error was raised (not sure if a warning did) and it totally slipped my mind to check the right case. Thanks a lot for your prompt reply! The issue is solved now with xRef.