Design and Analysis of a Box-like Wing Configuration through Panel-Methods
Author: Fahad Aman Khan
Master Thesis
Abstract
This work outlines the different aerodynamic aspects of box-wing design i.e. an
unconventional aircraft design configuration exhibiting the capability of reducing induced
drag. Being a nonplanar concept, the basic aerodynamic features differ from conventional
designs.
To understand these features and their influence on box-wing aerodynamics, parameter
variations have been conducted while Munk’s theorem is validated for stagger and sweep. In
this process, several important aspects of box-wing are highlighted. An optimization
algorithm has been implemented by considering all the design variables collectively to find
the global maximum for the box-wing design. All these investigations laid down the
important aerodynamic features of box-wing and also proved a method for estimating the
reduction in induced drag.
To conduct these investigations, vortex lattice methods (VLM) are used. Nonplanar systems
have certain limitations for best operations which provide maximum induced drag reduction.
These limitations are examined and applied in the form of constant and specified lift
distributions in the analysis. Furthermore, it is concluded that vortex lattice methods do
capture the reduction in induced drag correctly if the limitations of span loading are
maintained during the analysis.
Based on previous results obtained, Euler inviscid analysis for a selected box-wing and a
reference wing are carried out. The results of Euler inviscid analysis show good agreement
with the results achieved by vortex lattice method in drag reduction. Therefore, VLM
methods are capable of analyzing box-wing (and multi planar systems) to a good accuracy.
At the same time, transonic airfoil selection is identified as one of the key factors in
designing a commercial box-wing aircraft.
This study is closed up by discussing different potential advantages for the aviation industry
and discusses if a box-wing commercial aircraft should be made reality.
On the whole, this work looks into a possible way of investigating futuristic multi planar
aircraft configurations by using low fidelity aerodynamic codes.