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Projecte llegit

Títol: Anàlisi numèrica dels Gurney flaps en el rendiment d'un perfil alar

Estudiants que han llegit aquest projecte:

Director/a: MELLIBOVSKY ELSTEIN, FERNANDO PABLO

Departament: FIS

Títol: Anàlisi numèrica dels Gurney flaps en el rendiment d'un perfil alar

Data inici oferta: 27-01-2025     Data finalització oferta: 27-09-2025


Estudis d'assignació del projecte:
    GR ENG SIST AEROESP
Tipus: Individual
 
Lloc de realització: EETAC
 
Paraules clau:
Aerodinàmica, Gurney flap, NACA 0012
 
Descripció del contingut i pla d'activitats:
 
Overview (resum en anglès):
This work numerically analyzes how different Gurney flap configurations affect the aerodynamic performance of a NACA 0012 airfoil, used as a simplified model of a Formula 1 car's rear wing. The main objective is to determine which combination of flap height, angle of attack, and mounting angle maximizes aerodynamic downforce while maintaining acceptable efficiency in terms of the CL/CD ratio. To achieve this, two-dimensional CFD simulations are performed using OpenFOAM, considering an incompressible flow at a Reynolds number of 6x10^6 and employing the Spalart-Allmaras turbulence model on a C-shaped domain with a hybrid mesh (structured in the boundary layer and wake regions, unstructured elsewhere). The mesh and boundary conditions are validated beforehand by comparing the CL, CD coefficients and the Cp distribution of the NACA 0012 with NASA reference data, obtaining very similar values.
Starting from the baseline case, 2% and 4% chord Gurney flaps are introduced, with mounting angles of 90º and 45º, and angles of attack of 0º, 5º, and 10º. The time series of CL and CD show that, for certain configurations, the converged solution is oscillatory; therefore, a Fourier transform is applied to obtain mean values, amplitudes, and dominant frequencies of the oscillations associated with vortex shedding. The results indicate that the 2% Gurney flap clearly increases lift for all angles of attack, with a moderate increase in drag; for AoA = 10º, the CL/CD ratio remains very close to that of the baseline airfoil but with a significantly higher aerodynamic load. On the other hand, increasing the flap height to 4% further raises CL but almost doubles CD, strongly reducing the CL/CD ratio and producing oscillations of greater amplitude and lower frequency, with more intense vortex shedding that could compromise structural stability. Changing the mounting angle from 90º to 45º with a 2% flap at AoA = 10º results in a slight additional increase in CL and a slight decrease in CD, slightly improving the CL/CD ratio and eliminating steady-state oscillations.
The overall analysis of all simulations shows that the best CL/CD ratio is achieved with the baseline NACA 0012 airfoil at a 10º angle of attack; however, the configurations with a 2% Gurney flap at 10º (both at 90º and 45º) offer very similar ratios while providing a notable increase in aerodynamic load. This indicates that, in circuits with many curves, using a 2% Gurney flap can improve a car's cornering performance at the cost of a manageable increase in drag, whereas in circuits with long straights, the baseline airfoil without a flap remains preferable. The study concludes that the Gurney flap is an effective tool whose usefulness depends on the operating context of the racing car.

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