On vortex filament methods for linear instability analysis of aircraft wakes

Linear stability analysis of vortical systems is discussed in a systematic manner using the classic inviscid vortex filament method. Well-known results are recovered as special cases of a unified linearization procedure. The symmetries of the vortex systems analyzed are exploited to obtain an analytical picture of different classes of growing and decaying eigenmodes. Finally, comparisons with viscous global linear theory reveal the limits of applicability of the vortex filament method for the instability analysis of realistic vortex systems.