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Massive separation and dynamic stall on a cusped trailing-edge airfoil. (English) Zbl 0606.76048

Numerical and physical aspects of aerodynamic flows III, Proc. 3rd Symp., Long Beach/Calif. 1985, 286-317 (1986).
[For the entire collection see Zbl 0593.00028.]
The initial crossover from a predominantly attached flow to massive separation of the Kirchhoff form was examined through the use of the interacting-boundary-layer approximation. The predominantly attached flow over a cusped trailing-edge airfoil was calculated using the Hilbert integral form of thin-airfoil theory.
This flow structure terminated at a certain critical airfoil thickness, leading to an unsteady development which pointed towards stall and a crossover to massive separation. Above the airfoil thickness at which a predominantly attached flow ceased to exist, the thin-eddy form of steady-state massive separation was calculated using a new interacting- boundary-layer model.
This new model is based on the Kirchhoff free-streamline description of separation and can, in principle, switch between accurate inviscid eddy models and more accurate numerical calculations within the eddy when necessary. This model provides an attractive alternative to the classical form of interacting-boundary-layer theory when separation is present.
It is the opinion of the authors that this model can be generalized to include most, if not all, types of two-dimensional, incompressible separated flows. In particular, when corrections are made to thin-airfoil theory for thick bodies, the methods presented in this study should be capable of handling true bluff-body separation.

MSC:

76D10 Boundary-layer theory, separation and reattachment, higher-order effects
76G25 General aerodynamics and subsonic flows

Citations:

Zbl 0593.00028