Over the past years numerical simulation has become a more and more important technology in the design process of aircraft components. Nevertheless, today a lot of time is invested in the construction of expensive prototypes and their testing in the wind tunnel. Therefore, current effort is put into the development of a “numerical wind tunnel” in a virtual flight testing environment to reduce the costs during all stages of the design process. Together with the DLR, Airbus and several other partners from research and industry, Fraunhofer SCAI will try to achieve this aim.

The underlying systems that need to be solved numerically are based on the Navier-Stokes equations in case of flow simulations and the elasticity equations in case of mesh deforming. Looking at a detailed aircraft grid in three dimensions this leads to problems with at least millions of variables. Standard one level solvers are not scalable and, therefore, not able to solve those large equation sets in acceptable time.

As a hierarchical solver SAMG is well suited for large sets of equations. In contrast to geometric multigrid, which explicitly exploits information on the grid structure, algebraic multigrid only operates on the matrix equations. Therefore, it is easy to integrate as a plug-in solver into the existing simulation codes. Being rather a toolbox than a plain solver, isolated components of SAMG can be adjusted or exchanged to meet the new requirements of these specific industrial applications. This flexible framework has already proven itself successfully in the past, as the SAMG-package has become a well established tool in various branches of industry.

• more info (in German)

The project is supported by the

German Federal Ministry of Economics and Technology

Project coordinator:

German Aerospace Center (DLR), Institute of Aerodynamics and Flow Technology, Braunschweig, Germany

Duration:

January 2009 until March 2012

Contract number:

20A0801C