Time dependent adjoint-based optimization for coupled fluid–structure problems

What is it about?

A formulation for sensitivity analysis of fully coupled time-dependent aeroelastic problems is given in this paper. Both forward sensitivity and adjoint sensitivity formulations are derived that correspond to analogues of the fully coupled non-linear aeroelastic analysis problem. Both sensitivity analysis formulations make use of the same iterative disciplinary solution techniques used for analysis, and make use of an analogous coupling strategy. The information passed between fluid and structural solvers is dimensionally equivalent in all cases, enabling the use of the same data structures for analysis, forward and adjoint problems. The fully coupled adjoint formulation is then used to perform rotor blade design optimization for a four bladed HART2 rotor in hover conditions started impulsively from rest. The effect of time step size and mesh resolution on optimization results is investigated.

Featured Image

Why is it important?

• A fully coupled unsteady aeroelastic sensitivity analysis formulation is given. • Forward and adjoint sensitivity formulations are analogues of analysis formulation. • Fluid–structure interface information is dimensionally equivalent in all solvers. • A four bladed HART2 rotor shape is optimized in hover using the adjoint platform. • The effect of time step size and mesh resolution on optimization results is investigated.