Shock-induced scalar mixing and ignition under canonical shock-turbulence interactions (STI) will be considered first, by means of Direct Numerical Simulation in 3D and 2D, respectively. The effects of relevant physical parameters (shock and turbulence Mach numbers, and Reynolds number) will be highlighted on statistical changes along the shock-normal direction of scalar variance and dissipation-rate budgets, flow topology, and alignments of the scalar gradient with vorticity and strain-rate eigendirections. Shock-induced scalar mixing will also be addressed by tracking the downstream evolution of the geometry and physics of scalar structures initialized with a well-defined shape as they are transported and diffused by the background turbulence in STI, and compared with decaying homogeneous isotropic turbulence.
Flow-structure interactions of shock waves reflecting off turbulent boundary layers that develop along flexible walls will be addressed next, comparing results from ongoing numerical simulations with prior wind tunnel experiments. The calculations couple wall-modeled large-eddy simulation for the fluid flow, using an Arbitrary Lagrangian-Eulerian formulation, with an elastic solid structural solver that accounts for geometric nonlinearities, and a mesh deformation module based on a spring-system analogy. Strong shock/boundary-layer interactions resulting in mean flow separation and low-frequency unsteadiness that can interact with the natural frequencies of the structure will be emphasized.