Design, Analysis and Multi-Objective Constrained Optimization of Multi-Winglets

Sohail Reddy, Abraham Neiss, Shanae Powell (Florida International University)

CHALLENGE - Improvement in aircraft efficiency is necessary to maintain a profitable and stable aviation industry. The addition of winglets and winglet configurations have been implemented to various degrees of success but further optimization of a new category can further increase efficiency. A prototype Boeing 7E7 wing is optimized with various winglet configurations. The goal is to increase the efficiency from the blended winglets by 2%, by implementing Split-Scimitar winglets. 

SOLUTION - The chosen optimization method reduces computational cost while producing an optimum design. This study optimizes a multi-winglet configuration capable of increasing the lift-to-drag ratio by 2% with respect to the currently implemented blended winglets. The optimization is carried out using a Response Surface Approximation with 8 design parameters and 4 objective functions, coupled with genetic algorithm. The optimum winglet was tested at the Embry-Riddle’s subsonic wind tunnel to compare experimental and computational results. The multi-objective optimization in this study was carried out with modeFRONTIER, the four objectives being maximization of coefficient of lift and lift-to-drag ratio, while minimizing coefficient of drag and absolute value of the coefficient of moment.

BENEFITS -  The Split-Scimitar reduces drag by 2% from the currently implemented blended winglets that lead to $200 million of saving in jet fuel costs per year. These winglets have been optimized with 14% improved performance from a naked wing. The design in this report has reduced drag by 4% from our optimized blended winglets, resulting in slightly higher fuel saving. The cost reduction of this study was made possible thanks to the donation of the modeFRONTIER license, use of OpenFOAM and the use of the testing facility free of charge.