Sensitivity Analysis Methods for Complex, Multidisciplinary Systems

ABSTRACT: The objective of this proposal is to develop efficient sensitivity analysis methods based on adjoint techniques for multi-disciplinary time-dependent problems. The approach is based on the discrete adjoint, which is derived and implemented on a software component basis, with the various multidisciplinary software components being linked together through a Python interface, thus preserving modularity, and enabling the application of the adjoint approach to legacy disciplinary solvers. In Phase 1, coupled aeroelastic adjoint methods were demonstrated in two-dimensions and in three dimensions using a beam structural model. In Phase 2, more sophisticated brick and shell element structural models will be developed, along with their associated time-dependent adjoint models. These will be coupled to the aerodynamic solver with the goal of obtaining coupled multidisciplinary sensitivities for driving time dependent aeroelastic optimization problems. A thermal conduction model will also be developed with the goal of performing aero-thermo-elastic optimization. Target applications include fixed and rotary wing commercial and military vehicles as well as high speed vehicles. BENEFIT: The extension of adjoint methods to time-dependent multidisciplinary problems will enable new capabilities in computational aerospace engineering. Aeroelastic optimization through optimal selection of structural parameters and tradeoffs between aerodynamic performance and structural rigidity will be enabled. This will be of immediate use to government programs involved in the design of conventional fixed wing aircraft, rotorcraft, high altitude UAVs, and other non-conventional configurations. Aerothermoelastic optimization will also be enabled and will lead to more comprehensive design considerations for high speed vehicles. Commercial applications include the development of design tools for fixed and rotary wing commercial aircraft that combine in a unified manner both structural and aerodynamic design considerations.