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Near-Circular Foil Convergence Issue
Hi,
I am trying to obtain the Cl and Cd characteristics for a 2-D section around the root of a turbine blade. The profile is unlike a traditional airfoil profile, as is it more closely resembles a circle. My polar analysis is unable to converge and I’m not sure if its possible to alter the convergence criteria to generated a converged solution. I understand how complex analysing flow around a 2-D circle can be so I guess my answer roughly relates to how a circular foil automatically generates a 360 polar extrapolation. Maybe the issue relates to my coordinate file. Below is linked.
Hi,
for very “thick” airfoils (such as circular foils) the XFoil algorithm cannot converge and thus doesnt give a solution.
Typically this data can be obtained from experiments or CFD simulations.
By first principles, a completely cylindrical airfoil doesnt produce any lift, but only generates drag. In QBlade this drag value is a simple user input and nothing is computed when such a polar is generated.
BR,
David
