ESR15 | Mohammad Moniri Piri

One of the main factors which affect the fuel consumption of the airplane is the total drag. The more the total drag is, the more fuel needs to be burned during a specific flight. Nearly 50% of the total drag of airplanes is friction drag acting on different parts of the airplane, and a large portion of the friction drag is on wings. One of the main factors which determine the friction drag is friction coefficient, which is increased significantly when the transition occurs, i.e., flow becomes turbulent from laminar. The transition from laminar to turbulent takes place in a very complex process, but in general, the growth of amplitude of perturbations in boundary layer, which enter the boundary layer in a process called receptivity, can trigger the transition process.

Thus, it is particularly important to have a better understanding of receptivity and sensitivity of three-dimensional compressible flows to different types of perturbations and improved capability of predicting transition, which is the main goal of this project. One of the sources of perturbations on wings is surface irregularities, such as surface waviness which are always present at operational flight conditions. In this regard, one of the goals of this project is to provide a practical tool to investigate the effect of the surface waviness of wings on the growth of perturbations, so a better prediction of transition location can be made.