Application of active flow control to airfoils at ultralow Reynolds numbers

Aeronautics industry experienced its greatest expansion in terms of technological development in the Second World War and Cold War periods. Since then, progress has been made over the avionics, the aerodynamics, the airspace organization, management and infrastructure with the aim of optimizing them. This project wants to follow this line and to perfect the aerodynamic properties of an airfoil, to make it optimal not only in cruise conditions (the flight stage where the airfoil is going to be the majority of its useful life), but in each flight stage such as the take-off, landing, approach and ascension phases. So the project¿s investigation field will be the active control of the airfoil¿s boundary layer at high angles of attack and low Reynolds numbers, so as to emulate those critical flight stages that were mentioned before, using flux injection dispositives or sweeping jets placed at the wing¿s extrados. This aims to increase the aerodynamic efficiency of a three-dimensional wing by energizing the boundary layer in order to delay its separation while avoiding the use of movable parts. A sweeping jet consists of a fluidic actuator which emits a time and space oscillating jet without having any mechanical or electromagnetic part. The Reynolds numbers used are unrealistically low for actual aeronautical applications due to the interest in the physical mechanisms of actuation control, which are only feasible at very low Reynolds regimes. This study aims to expand the chord-wise positioning optimization studies, to the optimization in the span-wise direction of the positioning and self separation between actuators, taking advantage of the homogeneity in that direction, by using single modal and multi modal Fourier expansions of variable wave number in order to reduce computational complexity and time.Objectius de Desenvolupament Sostenible::9 - Indústria, Innovació i Infraestructur