On the interaction of an oblique shock with a flexible panel

In this communication, the dynamics of a flexible two-dimensional panel subjected to an impinging oblique shock is considered numerically in the inviscid regime. Computations have been performed for a Mach number equal to two and for several shock strengths employing a previously validated fluid–structural approach. Results show for the first time that for a sufficiently strong shock self-excited oscillations arise in the coupled system. Depending on the shock strength, either supercritical or subcritical bifurcations emerge at a value of dynamic pressure which can be considerably lower than that corresponding to standard panel flutter (i.e., in the absence of a shock). For fixed dynamic pressure, both the amplitude and frequency of the limit-cycle oscillations increase with the impinging shock strength. In addition to the incident and reflected oblique shocks, the unsteady flows are characterized by a shock at the plate leading edge and by a strong recompression and subsequent expansion near the trailing edge. The significant unsteadiness generated by the fluttering panel propagates along the reflected shock and trailing-edge recompression/expansion wave system with potential structural implications not only on the panel but on opposing surfaces in internal flow applications.