Frank Spiering

CTAU, A Cartesian Grid Method for Accurate Simulation of Compressible Flows with Convected Vortices

A zonal approach for simulation of compressible fluid flow is presented. Within this approach a Cartesian solver of fourth order spatial accuracy is used for simulation of convection of vortical structures over larger distances with small numerical losses.

Influence of Wing Elasticity on the Experimental and Numerical Determination of Dynamic Derivatives

The presented investigations deal with the analysis of dynamic derivatives of a modern transport aircraft configuration (DLR-F12). The conducted wind tunnel tests focused mainly on the measurements of unsteady forces, moments and pressure distributions. The measurements of the steady and unsteady wing deformations using two different wings were of significant importance. Those wings are designed to be ideal stiff on the one hand but also to allow more flexibility on the other hand, in order to investigate the effect of wing elasticity on the static and dynamic aerodynamic properties of this configuration. For the validation of the numerical tools calculations are performed based on the solution of the unsteady Reynolds-averaged Navier-Stokes (URANS) equations using a finite volume parallel solution algorithm with an unstructured discretization concept (DLR TAU-Code). The wing deformation is accounted for using the finite element code ANSYS.

Development of a Parallel Fluid-Structure Coupling Environment and Application to a Wind Tunnel Model under High Aerodynamic Loads

Accurate measurements of the aerodynamic performance in wind tunnel experiments require to retain dynamic similarity to represent the flow characteristics of real aircraft configurations. High Reynolds numbers for a full-scale aircraft in cruise flight are realized in wind tunnels by reducing the temperature to cryogenic conditions and increasing the static pressure to compensate for the smaller reference lengths. Clearly, this increases the aerodynamic loads to an extent that even rigid models show a significant deflection, depending on the flow conditions. Consequently the aeroelastic deflections have to be taken into account in a numerical simulation of a wind tunnel experiment.Usually this is done by coupling fluid dynamics and structural mechanics (see [3]).

Coupling of Flow Solvers with Variable Accuracy of Spatial Discretization

In this work a coupling procedure for flow solvers of different accuracies of spatial discretizations by the Chimera technique is introduced. To adapt the coupling procedure to the properties of the incorporated flow solvers, the accuracy of different interpolation methods is investigated. The coupling module used for the data transfer between the flow solvers is extended by a high order interpolation method and two test cases are presented to illustrate the effects of the interpolation methods on the flow solution.