DLR Results for the First AIAA Stability and Control Prediction Workshop

Abstract

A summary about the DLR results from the first AIAA Stability and Control Prediction Workshop is presented. To evaluate and improve the prediction accuracy of stability derivatives of common aerodynamic codes, five test cases, three mandatory and two optional, based on the NASA Common Research Model were set up to perform a validation using the experimental data performed at the ONERA wind tunnel. The first workshop had a strong focus on evaluating longitudinal static stability derivatives and detecting the influence and increments of the wind tunnel sting of the tested Common Research Model. A first step toward lateral static stability derivatives and a β-sweep was included in the optional test cases. At first, investigations should identify solution accuracy and grid convergence behavior with five provided unstructured grids. For the second test case, the impact on the longitudinal static derivatives with respect to a variation of the transonic Mach number was investigated. In comparison to the wind tunnel experiment the numerical simulations thereby underpredicted the drag and pitching moment, especially for Mach numbers greater than 0.83. The last test case was used to determine the increments of the wind tunnel sting. The sting hereby proved to have a great effect on the aerodynamics of the tail plane and lead to a positive shift in the pitching moment. In addition, DLR also computed the optional test cases by evaluating the lateral static derivatives in comparison to finite differences with a frequency domain solver, which is a time-linearized Navier-Stokes method. Ultimately, the effect of the sideslip angle on the aircraft with the wind tunnel sting was investigated.