The linear multi-lifting line code Lifting_Line features a higher order spanwise vortex sheet representation of the wake. Compared to vortex lattice codes, this improves the prediction of the lift distribution and the induced drag of a wing significantly. Furthermore, fewer elements are needed. However, the code represents the camber line surface only and is linear. Thus, it can not take thickness effects and viscous decambering effects, the deviation from linear lift curve close to stall, into account.

Therefore, we developed LiLi-NL, which makes it possible to consider this effects. Lookup-tables, either generated by XFOIL, CFD or from wind tunnel data are used to calculate the viscous effects fast. Furthermore, it is also extended by a trim solver. With that, the control surface deflections for maneuvering and circling flight conditions can be calculated and taken into account for the lift distribution and induced drag calculation. 
We also included a profile drag module. With this, the wing profile drag is calculated precisely for moderate to high aspect ratio wings.