A Coupled Inviscid–Viscous Airfoil Analysis Solver, Revisited
Krzysztof Fidkowski
Abstract
This paper presents a self-contained, comprehensive exposition and new elements of a classic airfoil analysis technique: an integral boundary-layer solver coupled to a vortex-panel potential-flow method. The resulting solver MFOIL, implemented in MATLAB and made freely available, builds on the XFOIL code and documentation, which serve as the inspiration, reference, and standard of comparison. Modifications made in the present implementation include an augmented-state coupled solver for more control in limiting the state update, a new stagnation-point formulation to reduce leading-edge oscillations in the boundary-layer variables, and a more robust treatment of the amplification rate near transition. Several results highlight these modifications and demonstrate capabilities of the code.