Résumé des résultats (Abstract)
(Anglais)
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The FLOWNET network aims to bring together industrial and academic partners on code validation issues for improving accuracy, efficiency and confidence in Computational Fluid Dynamics (CFD) within design processes.
EPFL has collaborated throughout the whole project with SMR (Bienne) on database structure, graphical representation and interfacing with the FLOWNET database format. Close collaboration with Dr. J. Favre CSCS/ETHZ (Manno) also for specific graphical needs.
In 1999 and 2000, EPFL made contributions on both low speed multi-element airfoils for turbulence model testing, in collaboration with SAAB, and hypersonic generic conditions for separation characteristics in collaboration with VKI. In 2001 and 2002, EPFL worked closely with RWTH-Aachen (Germany) on a complex 3 D configuration, ELAC, for which Aachen had made extensive experimental testing in both hypersonic and supersonic conditions. The ELAC configuration of the lower stage of a Two Stage to Orbit (TSTO) space transportation system proposed by German institutes of RWTH, Aachen, DLR and former DASA, (now EADS-M), The collaboration with RWTH allowed extensive comparison with the experimental works performed at Aachen both at the Aerodynamics Institute (AIA/RWTH) for Supersonic conditions (sustaining and cruise flight) and also within the Shock Wave Laboratory (SWL) for hypersonic ranges. The mesh generation problems were considerable, and the resultant grids were proposed to other partners for equivalent calculations. The results were presented at the ESA/ESTEC Symposium of Aerothermodynamics of Space Vehicles, and the International Conference on High Speed Flows at Marseille as joint papers with the groups at Aachen.
One of the key concepts of the ELAC system are the leeward vortex structures which are also visualised by complex vapour screen and PIV methods at Aachen. Work on vortex tracking and simulation visualisation was undertaken with SMR and Dr. J. Favre from CSCS/ETHZ at Manno, The results are particularly impressive with computational grids of up to 4 million cells.
Interfacing large data base systems from the EPFL/SMR ones to the FLOWNET requirements were proved to be impossible as the FLOWNET system did not account for such large scale applications. Significant work on data extraction and a new technology visualisation tool was performed with SMR.
EPFL attended all FLOWNET meetings and contributed to all workshops, in particular the special courses at VKI and DLR, and workshops at Rome, DLR-Göttingen, and Marseille.
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