Multigrid for Multidisciplinary Applications: Strip Steel Production

U. Becker-Lemgau
M.G. Hackenberg, B. Steckel, R. Tilch
German National Research Center for Information Technology,
Institute for Algorithms and Scientific Computing (SCAI),
Schloß Birlinghoven,
D-53754 Sankt Augustin, Germany


Within the GRISSLi project a coupling interface is developed for the coupling of different simulation codes and thus the solution of multidisciplinary problems. The twin-roller production of strip steel states such a multidisciplinary problem combining the flow of the liquid steel (casting) and the mechanical deformation of the solidified steel (rolling). As a near net shape casting method the twin-roller process reduces the production cost of thin strip steel and the manufacturing costs of thin strip steel production plants.

The fluid flow code is coupled with the structure mechanic code via the GRISSLi coupling interface which provides interpolation, communication and management of exchanged data. For fluid flow calculations the LiSS package developed at GMD is used. LiSS provides an environment for the parallel multigrid solution of partial differential equations on general domains and is proved to be very efficient for this purpose.

In order to enable a realistic simulation of the steel flow, the Navier-Stokes solver of the LiSS package had to be extended with a temperature equation, a turbulencemodel, and a solidification model.

Because of the complex flow patterns, the fluid flow simulation for the twin-roller process has to be performed in three spatial dimensions. As a result of this, the LiSS package has to be extended considerably. On the one hand, this challenging task is simplified by the use of CLIC, communications library for industrial codes. On the other hand, complex numerical questions, such as correct treatment of the combination of complex boundary conditions on curved boundaries, have to be solved successfully.

The focus of the talk will be on the LiSS package as a tool for the parallel multigrid solution of fluid flow problems with respect to the described multidisciplinary application of strip steel production. Several flow simulations and coupled calculation results will be presented.

This work was supported within the GRISSLi-project by the German Federal Ministry for Research and Education, contract no. 01 IS 512 C.