Adjoint-based sensitivity of turbulent reacting jets

In this talk, we present a discrete adjoint-based method for measuring local sensitivity in direct numerical simulations of turbulent reacting jets. We introduce a novel adaptive dissipation scheme compatible with the discrete adjoint formulation that preserves scalar boundedness while retaining high-order accuracy. A flamelet-progress variable approach is employed to handle chemical reactions using tabulated chemistry. The utility of using tabulated chemistry is that discrete adjoint sensitivity can be computed efficiently for arbitrary chemical mechanisms. Putting this together, direct numerical simulations of a three-dimensional reacting round jet are performed at moderate Reynolds numbers. Sensitivity obtained from the adjoint solution is used to study flame and chemistry responses to turbulent flow actuation.