Propagation of perturbations in the three-dimensional boundary layer on a delta wing in the viscid-inviscid interaction regime

The propagation of perturbations in the three-dimensional boundary layer on a planar delta wing in a hypersonic gas stream is investigated in the strong viscid-inviscid interaction regime. A characteristic associated with the induced pressure is found and an integral relation determining the velocity of its propagation is obtained. The directional diagrams of the propagation velocity of the characteristic surface in the boundary layer are determined for a series of constitutive parameters. This makes it possible to calculate the perturbation propagation velocities in the boundary layer when the velocity profiles in the longitudinal and transverse directions are known.