Active flow control in aerodynamic applications.
Tutor / directorBergadà Granyó, Josep Maria
Document typeMaster thesis
Rights accessRestricted access - author's decision
The focus of this thesis is to determine the e ect of Active Flow Control ( AFC from now), studying, analyzing the behavior of airfoil and afterwards, implementing AFC and evaluate its impact on aerodynamic performance. The case characteristics are a 2D airfoil NACA 2412 computed at Re = 5000, angle of attack 20º and viscid incompressible ow. The objective of AFC is to retard the boundary layer detachment in order to reduce the amplitude of the vortex shedding created at the wake and reduce the induced drag and nally reduce drag e ect in comparison with the previous and standard studied case without AFC. Many parameters of AFC are involved in results: blowing, suction or sinusoidal behavior, amplitude of the AFC region, location implementation, magnitude or energy phenomena requested, etc. This study has been able to study limited cases due to computation cost reasons. But applying several hypothesis, the study has been able to extract conclusions. Computations are performed using no model turbulence trying to recreate the Direct Numerical Simulation ( DNS from now) concept although it can not be de ned as DNS properly due to this is a 2D case and required y+ standards can not be reached for computational cost reasons. This case is developed under a laminar regime due to low Reynolds number. The low Reynolds number is high is the rst cell requested is for the same y+ requested. The reason why this case is based on low Reynolds number is due to using Reynolds-Averaged Navier-Stokes ( RANS from now) equations with no turbulence model trying to reproduce DNS concept is because low y+ is requested, which implies a high number of cells to protect a low y+ and a properly expansion ratio and y+ is related with the velocity case. If the velocity case is low, for a requested y+ will imply a high rst cell distance, which at the end it is related with the total cell case. This study has used open software called OpenFOAM which is been made to solve Navier-Stokes equations by Computatinal Fluid Dynamics ( CFD from now) between other applications. Results indicate that AFC is able to apply a positive e ect in aerodynamic performance in comparison with baseline case. Some AFC characteristic variables have been studied.