Impact of Micro Vortex Generators on Aerodynamic Performance
摘要
Aircraft and wind turbines experience substantial loads during gusts and manoeuvres, requiring robust and rigid structures. Consequently, strategies for flow control and load alleviation assume paramount importance as they facilitate the attenuation of both the magnitude and fluctuations of the aerodynamic loads impacting the structure. Recently, the scientific community has shifted its focus towards the use of devices capable of inducing load alleviation via vortex generation: the vortex generators (VG) [1–3]. In the framework of the European projects, CIRA initiated the RADAR (ContRollo Attivo Del flusso AeRodinamico) project in the “Greening” program, funded under PRORA DM 662 (PROgramma nazionale di Ricerche Aerospaziali). The project focuses on aerodynamics and flow control technologies and its aim is to demonstrate the effectiveness of “smart vortex generators” for preventing stall of the outer part of a wing and also for “load alleviation”, i.e. reducing the load at high speed when the wing is hit by a gust. The proposed concept consists of “Active Deployable Vortex Generators” (ADVG) that can be deployed when needed and disappear in cruise conditions, where they would cause an increase of the drag. The feasibility of a control system based on deployable vortex generators has to be studied. The purposes of the control by vortex generator are twofold. The VGs have to act in high-lift conditions to avoid/delay the tip stall of a high aspect-ratio wing and employed as a “load alleviation” system at high velocity. The successive step is to build a model that has to be tested in laboratory to verify the correct functioning of the control system. Finally, functional tests will be performed also in CIRA PT-1 wind tunnel to verify the performances of the VGs. In the first phase of the projects, two-dimensional CFD analyses were performed and the results compared with available experimental data in subsonic conditions [1] as numerical verification. Transonic flow conditions in two-dimensional configurations were then simulated [4]. Preliminary results revealed a significant influence of the device on the aerodynamic forces acting on the airfoil, suggesting promising potential for load alleviation, particularly under specific flight conditions.