Re-Effect on MiniTED Performance in High Speed: Validation and Prediction

Abstract

Within the EU-platform AWIATOR a numerical simulation on the aerodynamic effect of MiniTEDs on an Airbus A340-300 has been conducted at wind-tunnel and free-flight conditions for cruise-flight Mach number and lift coefficients. Therefor, a baseline aircraft cruise configuration and a cruise configuration with MiniTEDs applied to the wing trailing-edge have been simulated with the DLR TAU code. The MiniTEDs have been realised by the use of Split Flaps. The results show a good qualitative agreement with wind-tunnel experiments in terms of lift and drag, the MiniTED influence on the drag polar has been reproduced properly. Comparisons of wing-surface pressure-distributions show a good agreement with the experimental data in all wing sections and prove the MiniTED influence on the aerodynamic coefficients. At free-flight conditions the MiniTED influence is seen to increase compared to the wind-tunnel conditions. Here, the lift-enhancing effect increases and the drag differences compared to the baseline configuration are affected unfavourably. The minimum lift coefficient of profitable MiniTED use is shifted to higher lift. Remaining drag reductions at high lift coefficients diminish. The pressure distributions prove the altered MiniTED influence in detail and show that the deflection angle of the MiniTEDs is too high for free-flight conditions. An additional comparison of numerical and flight-test pressure distributions of the baseline configuration shows a good overall agreement when the in-flight wing-twist is being considered.