A. Rehman, K. Kontis

A computational study has been conducted using Fluent 6.1 to investigate the control effectiveness of a synthetic jet in two distinct flow field configurations: a stationary NACA 0015 airfoil at various angles of attack ranging from 0° to 20° and a NACA 0015 airfoil undergoing pitching motion (á = 150 100sinùt). Stationary NACA 0015 Airfoil Configuration: The baseline flow parameters were computed and compared with experimental data. The results were in complete agreement with experimental data and stall was found to occur at 15°. The control effectiveness of the synthetic jet on lift has been investigated. The optimum location of the synthetic jet was found at 28% of the chord length of the airfoil. The forcing velocity and forcing frequency were 12m/s and 900 Hz respectively. The increase in lift (compared to the baseline) was more pronounced at high incidences (10° to 20°). The effectiveness of synthetic jet reduces at low incidences (4° to 10°). At all incidences, increase in lift was accompanied with an increase in drag. Finally, the computed results suggest that imparting movement of flow far away from separation point is useful if lift enhancement is required while the location of synthetic jet close to separation point is suitable for drag reduction. Periodic Pitching NACA 0015 Configuration: The dynamic mesh model was employed to preserve the initial mesh grid connectivity. The airfoil was driven in a periodic cycle corresponding to a= 5° 10° sin?t with a reduced frequency (k) equal to 0.15. The synthetic jet was introduced at 28% of the chord length of the pitching airfoil. Two forcing frequencies 1500 and 900Hz and two forcing velocities 12 and 30m/s were used to investigate the control effectiveness of the synthetic jet on the performance of the pitching airfoil. The computed results indicated that a single synthetic jet was not able to suppress the vortex formation and shedding, however, the overall airfoil performance was enhanced. Finally, the dynamic mesh capability preserved the initial mesh grid connectivity as no convergence problem was encountered in the entire simulation.

CEAS/KATnet Conference on Key Aerodynamic Technologies, Bremen, 2005

Conference Paper

englisch

21,0 x 29,7 cm, 9 Seiten

DGLR-Bericht, 2005, 2005-07, CEAS/KATnet Conference on Key Aerodynamic Technologies - Proceedings; S.1-9; 2005; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn

NA

in getr. Zählung;

aerodynamics

Bibliothek

2005