Irregular self-similar configurations of shock-wave impingement on shear layers Articles uri icon

publication date

  • August 2019

start page

  • 889

end page

  • 927

volume

  • 872

International Standard Serial Number (ISSN)

  • 0022-1120

Electronic International Standard Serial Number (EISSN)

  • 1469-7645

abstract

  • An oblique shock impinging on a shear layer that separates two uniform supersonic streams, of Mach numbers M1 and M2 , at an incident angle sigmai can produce regular and irregular interactions with the interface. The region of existence of regular shock refractions with stable flow structures is delineated in the parametric space (M1,M2,sigmai) considering oblique-shock impingement on a supersonic vortex sheet of infinitesimal thickness. It is found that under supercritical conditions, the oblique shock fails to deflect both streams consistently and to provide balanced flow properties downstream. In this circumstance, the flow renders irregular configurations which, in the absence of characteristic length scales, exhibit self-similar pseudosteady behaviours. These cases involve shocks moving upstream at constant speed and increasing their intensity to comply with equilibrium requirements. Differences in the variation of propagation speed among the flows yield pseudosteady configurations that grow linearly with time. Supercritical conditions are described theoretically and reproduced numerically using highly resolved inviscid simulation.

keywords

  • free shear layers; high-speed flow; shock waves