Subsonic Airfoils Virginia Tech（亚音速翼型弗吉尼亚理工大学）.pdf

Subsonic Airfoils W.H. Mason Configuration Aerodynamics Class Most people don’t realize that mankind can be divided into two great classes: those who take airfoil selection seriously, and those who don’t. Peter Garrison, Flying , Sept. 2002 Typical Subsonic Methods: Panel Methods •  For subsonic inviscid flow, the flowfield can be found by solving an integral equation for the potential on the surface •  This is done assuming a distribution of singularities along the surface, and finding the “strengths” of the singularities •  The airfoil is represented by a series of (typically) straight line segments between “nodes”, and the nonpenetration boundary condition is typically satisfied at control points •  Some version of a Kutta condition is required to close the system of equations. node N - 1 N N + 1 2 1 4 3 panel See my Applied Computation Aero page for the derivation Comparison of Panel Method Pressure Distribution with Exact Conformal Transformation Results -2.50 PANEL -2.00 Exact Conformal Mapping -1.50 -1.00 C p -0.50 0.00 0.50 1.00 -0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 x/c XFOIL’s inviscid calculations use