AbstractRecent advances in two lifting surface methods are
reported. The present subsonic constant pressure
method improves upon the program robustness of the
doublet lattice method. The present unified
supersonic-hypersonic method extends the range of
applicability of lifting surface theory to the
Newtonian limit. Based on a uniformly-valid series
formulation, the method accurately approximates the
non-linear thickness effect, whereas this effect is
neglected by the linear theory and overestimated by
piston theory. In fact, the present results
generally agree well with the trends of several
Euler solutions. Among other findings, cases
computed by the unified method confirm that the
effect of thickness is to reduce the supersonic
flutter speed.</jats:p