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Projecte llegit

Títol: Active flow control on supercritical airfoils at high incidence

Estudiants que han llegit aquest projecte:

Director/a: MELLIBOVSKY ELSTEIN, FERNANDO PABLO

Departament: FIS

Títol: Active flow control on supercritical airfoils at high incidence

Data inici oferta: 18-07-2025     Data finalització oferta: 18-03-2026


Estudis d'assignació del projecte:
    GR ENG SIST AEROESP
Tipus: Individual
 
Lloc de realització: EETAC
 
Paraules clau:
Supercritical airfoil, aerodynamics, active flow control
 
Descripció del contingut i pla d'activitats:
Modern commercial aviation faces increasing demands for aerodynamic efficiency and safety, especially during critical phases like takeoff and landing. In these conditions, aircraft operate at low speeds and high angles of attack, where flow separation and loss of lift are significant challenges.

This project focuses on applying Active Flow Control (AFC) techniques, such as synthetic jets or controlled blowing/suction, to a supercritical airfoil, aiming to delay flow separation and improve aerodynamic performance near stall conditions.

The research will rely on CFD simulations using Nek5000 and/or NekRS to evaluate how different AFC configurations impact lift and drag coefficients under realistic low-speed, high-incidence flight conditions.

Work plan:

1) Study of the state of the art on flow separation and AFC techniques.

2) Selection of a suitable supercritical airfoil.

3) Setup of the CFD simulation framework using Nek5000/NekRS.

4) Mesh generation and numerical validation.

5) Initial simulations to identify where and how flow separation occurs.

6) Design and implementation of AFC configurations.

7) Evaluation of aerodynamic performance improvements.
 
Overview (resum en anglès):
Current research in civil aviation highlights the need to expand the operational envelope of supercritical airfoils. While optimized for transonic cruise, these airfoils suffer from severe boundary layer separation at low speeds and high angles of attack, limiting aircraft safety and maneuverability. This thesis proposes an Active Flow Control (AFC) strategy to mitigate deep stall on a NASA SC(2)-0012 supercritical airfoil at an extreme angle of attack of 17º.

To evaluate this, a high-fidelity Computational Fluid Dynamics (CFD) framework is established. Simulations are conducted using the RANS k-tau turbulence model within the high-order spectral element solver, NekRS. A Zero Net Mass Flux (ZNMF) Synthetic Jet Actuator (SJA) is implemented near the leading edge to actively control the separated flow through parametric optimization.

Results demonstrate that aerodynamic recovery can be achieved efficiently. Actuating at a dimensionless frequency of 1.5 and a momentum coefficient of 0.001 yields optimal performance, achieving a 36.11% increase in lift and a 49.14% reduction in drag. This drives an overall aerodynamic efficiency increase of 167.7%.

The key physical mechanism driving this recovery is deep momentum entrainment. The cyclical SJA momentum injection promotes near-wall mixing and breaks down the detached shear layer using discrete vortical structures. Concurrently, the ZNMF suction phase extracts decelerated fluid from the viscous sublayer, completely suppressing the baseline bluff-body shedding instability. Ultimately, this thesis delivers a robust computational framework that proves the viability of AFC to enhance supercritical airfoil performance at high incidences, laying the groundwork for future 3D simulations and wind tunnel testing.

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