Numerical investigation of the unsteady transition between asymmetric shock systems

Abstract

The dynamic interaction of two planar and asymmetric shock waves at a free-stream Mach number M¥ = 3 is studied numerically in order to characterize the transition between the regular (RI) and Mach (MI) interaction patterns. Shock deflection disturbances are independently introduced in the form of a sinusoidal oscillation of the shock generator. Selected amplitudes of oscillations ensure that both boundaries of the theoretical dual solution domain (DSD) are crossed every period. The range of angular frequencies investigated resembles the dynamics of the separation shock in shock-wave/turbulent boundarylayer interactions. Computational results show that the MI unambiguously prevails regardless of the initial wave pattern disturbed, provided that the oscillation frequency is not too large. This holds for mean conditions embedded inside the DSD. For those outside, a RI_MI alternation is observed when the initial wave pattern is a RI, and no single event of a RI interaction occurs when the initial patter is a MI.Aerodynamic