The primary objective of this Project is analyze the aerodynamic performance of a modified airfoil in two dimensions using a computer simulation program. To introduce the reader, briefly explains the basics of lift in vehicles with wings and the knowledge to improve the aerodynamic performance. It's explained with several details why the aircraft can fly and the hypothesis commoner to explain it. Finally it's explained the numerical calculation method used in this project. In this project, the process of analysis with and without modifications and similar devices are analyzed detailed. The relevant results obtained from simulations and experimental results are analyzed and discussed. Finally an assessment of the modification suggested and their advantages and disadvantages and performances according to the different phases of flight and their energy cost. The first simulation of the second chapter is with the airfoil NACA 0012 in a fluid velocity of 10 m/s. The second simulation it is with the same airfoil but with a velocity of 28 m/s. The last simulation in this chapter is the hypothesis suggested with NACA 0012 with a modification on a fluid at 28 m/s. At the end of this project is showed several specific vocabulary. It's explained a simple simulation that I used to understand the software. It's exposed another hypothesis suggested with an modification in an airfoil with a negative pressure. Additionally it's showed several designs of slat not optimized devices for the proper comparison.