@article{article_346425, title={Airfoil Optimization for Level Flight}, journal={Journal of Aviation}, volume={1}, pages={107–119}, year={2017}, DOI={10.30518/jav.346425}, author={Körpe, Sinan and Darak, Hakan}, keywords={Airfoil,Optimization,Sequential Quadratic Programming,Xfoil,MATLAB}, abstract={<p style="text-align:justify;"> <span lang="tr" style="font-size:10pt;line-height:107%;font-family:’Times New Roman’, serif;" xml:lang="tr">In this study, the
optimization problems that are based on C <sub>L </sub> and C <sub>D </sub> values,
which are obtained by a fast aerodynamic solver consisting of three dimensional
panel method and one-way two dimensional boundary layer solver, are solved for
four different speed values in level flight. These values are stall speed, the highest
range speed, the highest endurance speed and the maximum speed. In order to
solve the optimization problems, the combination of MATLAB program and Xfoil
program has been provided. Lift and drag force coefficients are calculated in
Xfoil program for the Jacobian matrix of the constraints and the gradient
vector of the objective function that are required by the sequential quadratic
programming method in MATLAB. In the first phase, minimization the drag coefficient
at the determined angle of attack is defined as the objective function while
the lift coefficient at that angle of attack is defined as the equality
constraint. In the second phase, in addition to the above defined problem, the
lift coefficient provided by the airfoil at the stall angle of attack is
defined as the equality problem and the optimization problems are solved. </span>     <br /> </p>}, number={2}, publisher={Vedat Veli ÇAY}