To be competitive, the development of commerical airplanes is only possible by a close cooperation of national and international research organisations and the aerospace industry. In the pre-development phase of commercial airplanes, today the numerical simulation of physical processes on a virtual product is absolutely necessary because of the enourmous competition and the high costs for a new airplane. With the classical experimental tests the necessity for decreasing developmental periods is not possible. In comparison to that, the numerical simulation still offers by fast model variation today a flexible alternative for the preselection of appropriate model configurations.

In the strong multi-disciplinary process of airplane development, in particular the aerodynamic is one of the most intensive users of supercomputers. In the near future the requirements on the simulation programs, the computing power and the work process are increasing strongly because of more and more complex engineering problems.

An example for such a problem is the optimization of components of an airplane in consideration of interactions between the airflow and the airplane structure.

Today team work is confronted with the fact, that for a specific problem the engineers, the simulation programs and the supercomputes are located at different sites.

A solution for this problem is the usage of multi-media communication between the development-teams in combination with interactive supercomputers for the simulation of physical processes, as well as the cooperative, interactive visualization of the results. This technology has been developed and used in projects with the essential europeaen aerospace companies (Daimler-Benz Aerospace Airbus, British Aerospace Airbus, Aerospatiale) as well as the research organisations DLR, ONERA, CIRA, INRIA and the University of Stuttgart since 1992. In the EC projects PAGEIN [Seitz 94], [Lang et al 95] and ADONNIS the cooperative visual simulation environment COVISE has been developed, which has been used for the cooperative, interactive visualization. European-wide multi-media conferences on workstations via an european ATM-pilot network for the cooperative analyzation of numerical flow-simulations on supercomputers has been realized in these projetcs for the first time.

Further development of this technology took place in the EFENDA project (efficient airplane development by the usage of high speed networks BMBF 602/5, 1996-1998) with the partners Daimler-Benz Aerospace Airbus, DLR-EA, GMD-SCAI, TUB-HFI, HSB-IAT and RUS. The aim of EFENDA was, to setup an infrastructure and software environment to enable cooperative work in the airplane pre-development between the geographical distributed project partners. The activities of the pre-development process chain in EFENDA are geometry adaption, numerical grid generation, numerical simulation, visualization for the analyzation of the results and, as input for a new loop in the process chain, the modification of the geometry.

For the integration of the whole process chain of the aerodynamic design the software environment COWOSTEA (cooperative workflow management system for engineering applications) is used. As network infrastructure between the partners the B-WiN (german broadband academic network) is used. The partners are connected to the B-WiN (see Fig. 1-1)) with bandwiths ranging from 2-34 Mbit/s. An important element for the cooperative team work in EFENDA is the video- and audio-conferencing. In EFENDA the tool InPerson on Silicon Graphics hardware has been used. For video- and audio-sessions with more than two partners a multicast-network (se Fig. 1-2) has been established between the partner workstations, using the german mbone-network mbone-de (see [Maiß und Fahner 97])

It has been shown, that the aerospace predesign process chain with the tools MegaCads, FLOWer, SURVIS, PLOT and PSM can be integrated and executed in an geographical distributed team using an collaborative software environment in combination with multimedia conferencing tools via an high speed network. In an evaluation phase of the project a tremendous reduction of the execution time of the whole process chain has been recognized.

An evaluation of the collaborative aspects of COWOSTEA has shown, that COWOSTEA can host more sessionpartners than popular conferencing tools (for example Netmeeting, a Microsoft tool). In a comparison with popular application sharing programs (for example JointX from Sietec), the COWOSTEA approach shows no performance loss for data intensive applications based on OPEN-GL or OPEN Inventor graphics.