Aerodynamic Design and Simulation

Aerodynamic Design and Simulation

The overarching goal of aerodynamic design is to specifically tune a product’s aerodynamic characteristics. A common goal is to improve efficiency—that is, to reduce drag and/or increase lift.

Design activities always require the ability to predict these characteristics efficiently, which is why they are closely linked to simulation methods and related topics (verification, uncertainties).

We work with open-CFD solvers (particularly SU2 and OpenFOAM) and and with the CFD-toolboxes of DLR. We cover all aspects of the process, from model preparation (CAD), meshing, and preprocessing to simulation control, postprocessing, analysis, and data mining.

LES-Simulation eines Profiles mit einem Zackenband zur Transitionsfixierung
At low Reynolds numbers, airfoils are prone to laminar separation bubbles, which usually generates a large drag. Turbulence can be generated in the boundary layer by a zigzag-tape, thus laminar separation can be prevented. The thickness of the zigzag-tape must be chosen carefully, because a tape that is too thick will itself generate a large drag. To develop accurate estimations, the details of artificially forced laminar-turbulent transition must be understood.
Adjoint Elbow
The optimization of flow bodies is usually very complex due to the extremely large number of degrees of freedom. Adjoint methods offer an approach to a very efficient optimization. In this case, the pressure drop of a 90° pipe elbow was minimized by numerically solving the adjoint equations.
DES-Simulation airbag inflator
Visualization of the flow field in the vicinity of an airbag cold gas inflator immediately after ignition. The helium discharges with supersonic velocity and forms a so-called "barrel-shock", which is highly unsteady. The buildup of the full flow takes about 0.5 milliseconds.

Selected References

ZHANG, J., FOHLMEISTER, L., SCHOLZ, P., Large-Eddy Simulation of Boundary-Layer Transition over a Zigzag Trip. AIAA Journal (2023). https://arc.aiaa.org/doi/10.2514/1.J062237

SCHNORR, E., SCHOLZ, P., RADESPIEL, R. A method to quantify the supersonic discharge of airbag cold gas inflators. Experiments in Fluids 63, 177 (2022). https://doi.org/10.1007/s00348-022-03521-7 (OpenAccess)

SCHOLZ, P., FRANCOIS, D.G., HAUBOLD, S., SHAOWEI, S., EILTS, P., WM-LES Simulation of a generic intake port geometry, SAE Journal of Engines, Vol. 11, Nr. 3, 2018, doi: 10.4271/03-11-03-0023

PLACZEK, R., SCHOLZ, P., Flow Field Analysis of a Detailed Road Vehicle Model based on Numerical Data, In: Dillmann, A. et al. (Eds), Notes on Numerical Fluid Mechanics and Multidisciplinary Design X, Volume 132, S. 433-442, 2016, doi: 10.1007/978-3-319-27279-5

MAHMOOD, S., SCHOLZ, P., RADESPIEL, R., Numerical Design of Leading Edge Flow Control over Swept High-Lift Airfoil, Aerotecnica Missili & Spazio, The Journal of Aerospace Science, Technology and Systems, Vol. 92, No. 1/2, 2013