Shape optimization in industry

M. Albertelli (Renault), F. Jouve (Paris 7)

Shape optimization of automotive exhaust systems with continuous adjoint flows solvers

Christof Hinterberger (Faurecia Emissions Control Technologies); Mark Olesen

Meeting backpressure and flow uniformity requirements within severe packaging constraints presents a particular challenge in the layout of catalyst inlet cones.
A continuous adjoint geometry optimization tool (CAGO), has been developed at Faurecia Emissions Control Technologies[1,2], which finds suitable shapes for catalyst inlet cones directly from the package space. CAGO is based on the continuous adjoint formulation by C. Othmer et al. [3, 4] and it is implemented within the open source CFD toolbox OpenFOAM®.
CAGO starts from the provided package space and produces a design proposal, which is used as a reference surface in the CAD process. Subsequently, the CAD design is validated in a fully compressible flow analysis, where the catalysts are modelled as anisotropic porosities. For further optimization of flow uniformity and pressure drop, surface sensitivities are computed by solving the adjoint flow fields with a frozen density and frozen viscosity assumption.
The CFD optimization workflow will be presented together with various optimization examples (catalyst cones, exhaust tail pipe, HVAC air duct).

[1] C. Hinterberger, M. Olesen, "Automatic geometry optimization of exhaust systems based on surface sensitivities computed by a continuous adjoint CFD method in OpenFOAM", SAE 2010-01-1278 (2010)
[2] C. Hinterberger, M. Olesen, "Industrial Application of Continuous Adjoint Flow Solvers for the Optimization Of Automotive Exhaust Systems", in proceedings of ECCOMAS CFD & Optimization conference, Antalya (2011)
[3] C. Othmer, E. de Villiers and H.G. Weller, "Implementation of a continuous adjoint for topology optimization of ducted flows", AIAA-2007-3947 (2007)
[4] C. Othmer, "A continuous adjoint formulation for the computation of topological and surface sensitivities of ducted flows", Int. J. Num. Meth. Fluids, Vol. 58, pp. 861-877 (2008)

Structural optimization of automotive chassis: theory, set up, design

Marco Cavazzuti (Università degli Studi di Modena e Reggio Emilia); Luca Splendi

Improvements in structural components design are often achieved on a trial-and-error basis guided by the designer know-how. Despite the designer experience must remain a fundamental aspect in design, such an approach is likely to allow only marginal product enhancements. A different turn of mind that could boost structural design is needed and could be given by structural optimization methods linked with finite elements analyses. These methods are here briefly introduced, and some applications are presented and discussed with the aim of showing their potential. A particular focus is given to weight reduction in automotive chassis design applications following the experience matured at MilleChili Lab.

CMAP UMR 7641 École Polytechnique CNRS, Route de Saclay, 91128 Palaiseau Cedex France, Tél: +33 1 69 33 46 00 Fax: +33 1 69 33 46 46