Zaccara, Mirko (2022) Experimental investigation of wingtip vortices control with synthetic jets. [Tesi di dottorato]

[thumbnail of Zaccara_Mirko_34.pdf]
Anteprima
Testo
Zaccara_Mirko_34.pdf

Download (98MB) | Anteprima
Tipologia del documento: Tesi di dottorato
Lingua: English
Titolo: Experimental investigation of wingtip vortices control with synthetic jets
Autori:
Autore
Email
Zaccara, Mirko
mirko.zaccara@unina.it
Data: 14 Marzo 2022
Numero di pagine: 148
Istituzione: Università degli Studi di Napoli Federico II
Dipartimento: Ingegneria Industriale
Dottorato: Ingegneria industriale
Ciclo di dottorato: 34
Coordinatore del Corso di dottorato:
nome
email
Grassi, Michele
michele.grassi@unina.it
Tutor:
nome
email
Cardone, Gennaro
[non definito]
Greco, Carlo Salvatore
[non definito]
Data: 14 Marzo 2022
Numero di pagine: 148
Parole chiave: synthetic jet; wingtip vortices; flow control; PIV
Settori scientifico-disciplinari del MIUR: Area 09 - Ingegneria industriale e dell'informazione > ING-IND/06 - Fluidodinamica
Depositato il: 30 Mar 2022 12:03
Ultima modifica: 28 Feb 2024 10:59
URI: http://www.fedoa.unina.it/id/eprint/14416

Abstract

Wingtip vortices are proven to be detrimental to both aircraft efficiency and safety due to their adverse effects such as wake hazard, blade vortex interaction (BVI) noise, and induced drag. Despite the extensive literature on the subject, the number of experimental works featuring far field velocity measurements under active control are very limited. The present thesis presents the experimental investigation of the effectiveness of synthetic jet actuation control on the wingtip vortices and their wake hazard. In order to preserve the mutual induction of the counter-rotating vortices during their evolution, an unswept, low aspect ratio, squared-tipped, finite-span wing is employed. The synthetic jet actuation is based on triggering the inherent instabilities of Crow and Widnall at different momentum coefficient Cμ with the goal to reduce the vortices strength, the induced circumferential velocity, and to obtain an anticipated vortices break up. Different exit geometries of the synthetic jet have been tested to analyze the effects of the jet velocity and jet position changes on the wingtip vortices. A proper phase-locked stereoscopic particle image velocimetry setups have been designed to carry out such a parametric study in the near and far wake at a distance from the wing trailing edge up to 2 and 80 chord lengths, respectively. The effects of blowing at high momentum coefficient Cμ=1% are demonstrated to be remarkable on the wingtip vortices mitigation but the implementation of this control configuration on a real-scaled wing could be unfeasible. On the other hand, both the time and phase-averaged results suggest that, at relatively low value of Cμ=0.2%, using a larger synthetic jet exit section area allows to greatly affect the wingtip vortices features causing a striking alleviation of the vorticity distribution up to 90% with respect to the baseline reference case. As a matter, due to the actuation at low frequency, the vortices instability is prematurely risen up and amplified, leading to an early vortices linking and their consequent dissipation.

Downloads

Downloads per month over past year

Actions (login required)

Modifica documento Modifica documento