Section: New Results

Perturbation Methods

Participants : Alain Dervieux, Laurent Hascoët.

In the context of the European project NODESIM-CFD, the contribution of Tropics involved mainly the differentiation of perturbation methods and reduced order models for the management of uncertainties. These methods rely on Taylor series with second-order terms. The production of second derivative code is obtained through repeated application of Automatic Differentiation. Three strategies can be applied to obtain (elements of) the Hessian matrix, named Tangent-on-Tangent (ToT), Tangent-on-Reverse (ToR), and Reverse-on-Tangent (RoT). These new methods are disseminated through short courses, as those given by Alain Dervieux at ERCOFTAC sessions (Munich and Hampton). The application and extension of these methods have motivated a joint application from the Italian Aircraft company Alenia and Tropics in a FP7 proposal (Proposal CARDINA, nov. 2011).