Formation and Simulation of Tunable Dimples on the Surface of a Symmetrical Airfoil

Abstract

As commercial and private flight has become more widespread, efficiency and high-performance standards for aircraft are more important than ever. Dimpled services have been proven to reduce drag and improve aerodynamic performance for many simple geometries, as most commonly seen with golf balls. New research has also developed a method to tune these surfaces to maximize drag reduction in different flow conditions by changing the surface dimpling pattern. However, there is limited research into the use of tunable surface dimpling applied to more complex geometries. This thesis project seeks to study the formation and tunability of dimpling patterns on the surface of a NACA 0018 airfoil composed of a thin, stiff outer shell and a soft inner layer. PTC Creo 7.0 was used to design models of a NACA 0018 airfoil and a spherical test case to simulate the formation of wrinkles or dimples on the objects’ surface. The CAD models created in Creo were analyzed with Creo’s built-in simulation software to undergo static and buckling analyses with an applied pressure load over the model surface. After running static and buckling analysis on the models, dimpling in select locations consistent with predicted values was observed on the sphere model; however, despite repeated attempts to simulate wrinkling on the airfoil surface, no dimples or wrinkles were observed in the simulations performed. With further simulations and physical experimentation using this project as a starting point, there are many possibilities for studying how tunable dimples form on complex geometries and their application to drag reduction in the aviation industry.