Linear stability of a counter-rotating vortex pair approaching an inviscid wall

Abstract The influence of an inviscid planar wall on the temporal development long-wavelength instability a trailing vortex pair is formulated analytically and studied numerically. center positions deformation perturbations vortices are marched forward in time via filament method based Biot–Savart induction. An optimal perturbation analysis system determines wavenumber initial condition that yield maximum growth for any instant time. Direct integration highlights its sensitivity to conditions dependence wavenumber, which not features classical free pair. As counter-rotating approaches wall, shifts higher value than what predicted Crow unbounded fluid. present demonstrates local suppression near may be described without recourse viscous fluid arguments. Graphical abstract