Note on the Kutta condition in Glauert's series solution of the thin airfoil problem

Note on the Kutta condition in Glauert's series solution of the thin airfoil problem

Rienstra, S.W.

National Aerospace Laboratory NLR

1984-07-21

In this note the classical Glauert's series solution of the thin airfoil problem is reconsidered. Glauert's solution involves a transformation of the independent variable, and a Fourier sine-series expansion. It is shown that, in contrast to what is frequently stated, the sine-series does not imply the Kutta condition. The Kutta condition is satisfied only if the (usually tacit) assumption is fulfilled that divergent series are excluded. This is due to the squareroot singularity having been transformed into a non-integrable singularity. Indeed, the general solution (with an arbitrary circulation strength) can be obtained, in terms of generalised functions, with the eigensolution represented by a divergent series.

http://resolver.tudelft.nl/uuid:23508536-25f9-4a9f-be0e-a1a44888139c

Nationaal Lucht- en Ruimtevaartlaboratorium

Campus only

NLR MP 85002 U

Aerospace Engineering Reports

report

(c) 1984 National Aerospace Laboratory NLR