Thick Strip Method for Efficient Large-Eddy Simulations of Flexible Wings in Stall

Authors: Mohsen Lahooti, Rafael Palacios, Spencer J. Sherwin
Institute: Imperial College London

An extended abstract was submitted to the AIAA SciTech conference including some premileminary result of Nektar++/SHARPy FSI code.

Abstract: An efficient computational method is presented based on the “thick“ strip method for large eddy simulation (LES) of flexible wings in stall. Fluid domain is broken down into a series of smaller 3D strips where they can be efficiently solved with LES method for fluid flow. Force and moments are obtained from each strips and used to evolve the nonlinear dynamics of the wings.

The preliminary result presented for high-altitude long-endurance wing clearly show the capability and robustness of the presented approach.

Figure 1 (a) shows the the distribution of thick strips along the HALE wing, 8 thick-strips fluid domain is used for the simulation (b) Schematic of the solution domain (side view) with domain dimensions and boundary conditions
Figure 2. Preliminary results for wing deformation obtained from Nektar++/SHARPy FSI code with Re=1.56E6 and angle of attack of 4 degree (a) Wing deformation at several time instances where the abscissa indicates the coordinate along the wing span and ordinate shows the the non-dimensional deformation in cross flow direction (b) Time history of wing tip deformation
Figure 3. Contours of Q-criterion [0-5] for the airfoil with spanwise length (a) Lz=0.1c (b) Lz=0.2 The results show that the effect of spanwise length of the thick strips and indicates that using appropriate spanwise resolution, the solution is able to capture the local 3D effect for Lz>0.1c