Gradient-Based optimization of CRM wing-alone and wing-body-tail configurations by RANS adjoint technique

摘要

This paper describes the work performed by Onera for the third optimization workshop organized by the AIAA Aerodynamic Design Optimization Discussion Group (ADODG). For this purpose, several aerodynamic optimization problems were defined between 2013 and 2015 by the ADODG. During last two years, Onera performed optimizations on two test cases: a two-dimensional inviscid airfoil optimization problem (NACA0012 airfoil) and a three-dimensional wing-alone optimization problem (CRM wing configuration). In the frame of this third workshop, Onera pursued his activities, using the in-house elsA code, on the second test case (CRM wing configuration) and performed optimizations on the new one defined by the ADODG in 2015. This new test case consists in a three-dimensionnal wing-body-tail optimization problem (CRM wing-body-tail configuration). For the CRM wing alone test case, ONERA investigated the impact of, first, the differentiation of the Spalart Allamaras turbulence model in the adjoint solver and second, the use of a new parameterization technique based on the free-form approach. Based on these enhancements, new optimizations are presented. For this first test case, ONERA also analyzed in details the results and the optimized configurations obtained by University of Michigan in the frame of the previous workshops. This analysis is based on far-field drag decomposition. Regarding the second test case (CRM wing-body-tail configuration), first optimization results are presented including the horizontal tail rotation handling in order to design trimmed optimized configurations.