Adjoint-Based, CAD-Free Aerodynamic Shape Optimization of High-Speed Trains

Abstract

Following Othmer’s work on the continuous adjoint formulation for the computation of sensitivities of incompressible, steady-state, ducted flows, we will introduce an iterative, CAD-free, continuous, adjoint-based shape optimization procedure using gaussian filtered sensitivities and mesh morphing with radial basis function interpolation based on the approach described by for the optimization of the front part of the simplified model of a conceptual, generic highspeed train with respect to drag and pressure wave via single- and multi-objective optimization. We will show that, during pressure wave minimization, it was mainly the area with the widest sidewise extension in the bogie section which was affected by the strongest modifications while, on the other hand, for drag optimization the most sensitive areas and significant changes can be found in the front part of the nose tip section. First multi-objective investigations for two-dimensional testcases will show the influence of weighting and morphing parameters on the optimization process involving objective functions for drag and pressure wave.