Sensitivity Analysis Methods for Complex, Multidisciplinary Systems

ABSTRACT: The Phase I technical objective is twofold. First, the ZONA/MIT team will develop an Unsteady Aero-Structural Adjoint (UASA) methodology and implement it in a 2-D unsteady Euler solver. The objective of the effort is to investigate and resolve the technical issues involved in the development of the proposed UASA methodology. In this effort, we will first identify the pros and cons of a discrete Unsteady Euler Adjoint Solver (UEAS) against a continuous UEAS. Then, the selected UEAS will be coupled with a reduced-order structural adjoint solver to demonstrate the capability of the coupled unsteady adjoint solver in handling challenging cases, including non-autonomous systems with very long time scales, and systems exhibiting periodic and non-periodic limit cycle oscillations. This effort can remove all the technical obstacles involved in the development of the 2D UASA methodology and pave the way for its 3D extension in Phase II. BENEFIT: The proposed ZEUS-AD) code will become a unique tool, which will be the only flexible adjoint framework suitable for very large problems involving numerous objectives and constraints for aircraft sizing and shape optimization available to the aerospace market in the next few years. ZEUS-AD will become an industry standard, providing analyses for unsteady aeroelastic problems, such as flutter, maneuver loads, gust loads, static aeroelastic/trim, and nonlinear aeroelastic analysis, along with including shape and sizing optimization while accounting for aeroservoelastic and aerothermoelastic interactions. ZEUS-AD can be adopted for sizing and shape optimization of a wide class of aerospace vehicles: UAV/UCAV, supersonic transports, space launch vehicles, RLVs, blended wing/body, flying wings, joined-wings, hypervelocity missiles, winged projectiles (with optimized fin/canard/wing). It will be an important Aeroelastic/ASE design tool for current Air Force projects including conventional and revolutionary vehicles. Potential customers include the R & D and design arms of the Government, along with the aerospace industry worldwide, many of which are existing ZONA software users.