Fluid-Structure Interaction and Coupled Sensitivity Analysis for Design Optimization of Both Static and Dynamic Aeroelastic Problems
Wednesday, December 2, 2015 - 1:30pm to 3:00pm
Dr. Seongim Choi, Aerospace and Ocean Engineering, VirginiaTech
High-fidelity analysis and design of dynamic aeroelasctic problems, including aircraft wing flutter or helicopter rotor blades flows in forward flight, requires time-dependent solutions of both aerodynamics and structures. Efficient adjoint solution method for sensitivity analysis and design becomes expensive for these problems in time and memory. On the other hand, a time-spectral formulation of the governing equations of fluids and structures reduces the time-dependent FSI analysis represented in a pseudo-time domain and enables the steady adjoint method directly applicable to unsteady flow design. A Fourier-spectral method was successfully used to predict helicopter rotors in unsteady forward flight through a loosely coupled CFD/CSD analysis. Recently, a Chebyshve-spectral method was developed to solve non-periodic flows or flows with unknown frequencies. Flutter analysis of AGARD445.6 wing will be discussed which is carried out by the FSI analysis using a traditional time-accurate approach and the time-spectral solution method. Coupled adjoint sensitivity analysis method is implemented in the time spectral formulation-based FSI analysis method and the derivative values of unsteady aerodynamic forces are compared with the finite difference results. The design framework of time-spectral and adjoint-based method can be applied to many areas of the engineering design problems including co-axial contra-rotating open rotor, wind-turbine blade and flapping wing.
Bio and career highlights
Dr. Seongim Choi is currently an Assistant Professor in the dept of Aerospace and Ocean Engineering, Virginia Tech. Prior to working in Virginia Tech, she worked as an Assistant Professor in Korea Advanced Institute of Science and Technology (KAIST) from 2010~2013. She received her Ph.D from Stanford in 2006, and B.S. and M.S. from Seoul National University. She received an AIAA MDO best paper award for her Ph.D work on the MDO of low-boom supersonic jets. She worked as a post doctorate fellow in the U.S. Aeroflightdynamics Directorate (AFDD) working on helicopter rotor flow analysis and design. She received a young investigated award from the 1st Asian Rotorcraft Forum in 2012 for her work on the time-spectral and adjoint-based design method for helicopter rotor flows.