Automatic Geometry Optimization of Exhaust Systems Based on Sensitivities Computed by a Continuous Adjoint CFD Method in OpenFOAM Faurecia Emissions Control Technologies

Format:

Conference/Event

Author/Creator:

Hinterberger, Hinterberger, author.

Contributor:

Olesen, Mark

Conference Name:

SAE 2010 World Congress & Exhibition (2010-04-13 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2010

Summary:

Meeting backpressure and flow uniformity requirements withinsevere packaging constraints presents a particular challenge in thelayout of catalyst inlet cones. In these cases, a parameterizedoptimization of the potentially complex cone geometries isinefficient (and inappropriate). Even assuming that aparameterization of the complex surface forms is possible, thechoice of parametric shapes invariably affects the achievableresults. Additionally, the long computation time for solving theflow fields limits the number of shape parameters that can beconsidered.To overcome these restrictions, an optimization tool has beendeveloped at EMCON Technologies that is based on the continuousadjoint method (augmented Lagrange method) of Othmer and others Theopen source CFD toolbox OpenFOAM® is used as the platform for theimplementation. Since the geometry itself is modeled using animmersed boundary method (in which finite volume cells are markedas fluid or solid), no geometry parameterization is required. Themethod allows computation of the sensitivity of flow uniformity andenergy dissipation (or other target quantities) based on theinstantaneous geometry. After the calculated surface sensitivitiesare combined and corrected for manufacturing and topologicalconstraints, the location of the immersed boundary is automaticallyadjusted. It is thus possible to automatically determine a feasiblecatalyst cone geometry starting from an amorphous box (representingthe packaging constraints) that is supplemented by definitions ofinflow boundaries (for the flow coming from different manifoldrunners) and the outflow boundary (the catalyst surface). Thecalculation time associated with the process is on the same orderof magnitude as the solution of the RANS equations itself. Theoptimization tool, its theoretical basis and some practical resultsare presented in the paper

Notes:

Vendor supplied data

Publisher Number:

2010-01-1278

Access Restriction:

Restricted for use by site license