Flow control on a 3D backward facing ramp by pulsed jets

Pierric Joseph; Dorian Bortolus; Francesco Grasso

doi:10.1016/j.crme.2013.12.010

Separation flow control

Flow control on a 3D backward facing ramp by pulsed jets

Pierric Joseph ¹ ; Dorian Bortolus ¹; Francesco Grasso ^1,²

¹ Institut aérotechnique (IAT–CNAM), 15, rue Marat, 78210 Saint-Cyr-l'École, France
² CNAM, Laboratoire DynFluid, 151, boulevard de l'Hôpital, 75013 Paris, France

Comptes Rendus. Mécanique, Flow separation control, Volume 342 (2014) no. 6-7, pp. 376-381.

Abstract
Résumé

This paper presents an experimental study of flow separation control over a 3D backward facing ramp by means of pulsed jets. Such geometry has been selected to reproduce flow phenomena of interest for the automotive industry. The base flow has been characterised using PIV and pressure measurements. The results show that the classical notchback topology is correctly reproduced. A control system based on magnetic valves has been used to produce the pulsed jets whose properties have been characterised by hot wire anemometry. In order to shed some light on the role of the different parameters affecting the suppression of the slant recirculation area, a parametric study has been carried out by varying the frequency and the momentum coefficient of the jets for several Reynolds numbers.

Ce travail présente une étude expérimentale du contrôle d'un décollement dans le sillage d'une rampe descendante 3D par jets pulsés. Cette géométrie a été choisie pour reproduire un écoulement d'intérêt pour l'industrie automobile. L'écoulement de base a été caractérisé par PIV et mesures de pression. Les résultats montrent que la topologie de type tricorps est correctement reproduite. Un système de contrôle basé sur des électrovannes a été utilisé pour créer les jets pulsés, dont les propriétés ont été caractérisées par anémométrie à fil chaud. Afin d'éclairer le rôle des paramètres affectant la suppression de la zone décollée, une étude paramétrique a été menée en changeant la fréquence et la quantité de mouvement injectée pour différents nombres de Reynolds.

Received: 2013-07-26
Accepted: 2013-12-14
Published online: 2014-06-01

DOI: 10.1016/j.crme.2013.12.010

Keywords: Flow control, Pulsed jets, Backward facing ramp, PIV
Mots-clés : Contrôle d'écoulemement, Jets pulsés, Rampe descendante

Author's affiliations:

Pierric Joseph ¹; Dorian Bortolus ¹; Francesco Grasso ^{1, 2}

¹ Institut aérotechnique (IAT–CNAM), 15, rue Marat, 78210 Saint-Cyr-l'École, France
² CNAM, Laboratoire DynFluid, 151, boulevard de l'Hôpital, 75013 Paris, France

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     author = {Pierric Joseph and Dorian Bortolus and Francesco Grasso},
     title = {Flow control on a {3D} backward facing ramp by pulsed jets},
     journal = {Comptes Rendus. M\'ecanique},
     pages = {376--381},
     publisher = {Elsevier},
     volume = {342},
     number = {6-7},
     year = {2014},
     doi = {10.1016/j.crme.2013.12.010},
     language = {en},
}

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Pierric Joseph; Dorian Bortolus; Francesco Grasso. Flow control on a 3D backward facing ramp by pulsed jets. Comptes Rendus. Mécanique, Flow separation control, Volume 342 (2014) no. 6-7, pp. 376-381. doi : 10.1016/j.crme.2013.12.010. https://comptes-rendus.academie-sciences.fr/mecanique/articles/10.1016/j.crme.2013.12.010/

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