A Numerical Assessment of Side Plate Effects for a Low Aspect Ratio Wind Tunnel Model with a Smart Droop Nose Device

Abstract

This paper describes a numerical investigation of side plate effects on a quasi-2D wind tunnel model with very small aspect ratio. The target configuration is a two-element high lift profile with a smart droop nose device in landing position. The content of this paper is motivated by a large scale wind tunnel experiment in the Russian Tsagi T-101 wind tunnel in August 2012. Strongly driven by structural and technological aspects, the dimension of the final model is only 5mx3m. Naturally, 3D effects will occur affecting the flow in the middle section. For the damping of these effects, side plates are installed at the tips of the airfoil. The main aspect of the paper is the assessment of different side plate sizes, shapes, and positions and their impact on the flow behavior. For a selected case, the CFD computations are analyzed concerning grid influence and turbulence modelling in 2D and 3D. For the main study the SAO-model was chosen over a k-omega model due to its better grid convergence. In 3D, the asymptotic range of grid convergence is reached and an intermediate grid is found to be sufficient. Regarding the side plate influence, size and positioning of the plates is decisive for the aspired two-dimensionality of the aerodynamics. The main driver is the vertical distance between plate upper edge and airfoil nose.