نوع مقاله : مقاله پژوهشی
دانشکده مهندسی هوافضا، دانشگاه صنعتی شریف
عنوان مقاله [English]
Currently, the \ Dielectric \ Barrier Discharge \ (DBD) plasma actuators are going to be one of the most promising active flow control devices. They have a significant effect on the flow characteristics such as reducing the drag, postponing the laminar to \ turbulent flow transition, suppressing \ the separation and noise \ reduction. Here, a Single Dielectric Barrier \ Discharge (SDBD) plasma actuator, installed at the \ leading edge of a \ NACA0015 airfoil, was used to control the flow separation at a high angle of attack in a steady condition. The actuator was supplied with a 9kV voltage. The air flow was considered turbulent incompressible flow with a Reynolds number of about 500,000. An SDBD plasma actuator can generate a wall-bounded jet without any mechanical moving parts. Lack of a reliable simulation model prevents wider application of such DBD actuators. A complete numerical simulation of interactions of the electrostatic and the fluid flow field is very time-consuming. In this study, a semi-empirical Electrostatic model, with the plasma actuator induced body force, with two simple equations to predict the electrostatic filed, is used. To describe the two-dimensional flow field induced by the actuator, the body force is added to the CFD solver as a source term. The Electrostatic model solves the electrical potential and plasma concentration equations around the DBD electrodes by rectifying the plasma distribution over the aerodynamic surface, a modified form of the model is utilized which is shown to produce results close to the experimental data. The accuracy of the used model is indicated with the validation of fluid flow solution and modified electrostatic model with credit experimental results in the literature. It is shown that by employing a plasma actuator, the separation angle of attack increases from 15 to 21 degrees. The maximum lift coefficient is improved about 30-percent, while the maximum lift to drag ratio is improved more than 15\%.