Show simple item record

dc.rights.licenseRestricted to current Rensselaer faculty, staff and students. Access inquiries may be directed to the Rensselaer Libraries.
dc.contributorAmitay, Michael
dc.contributorHicken, Jason
dc.contributorSahni, Onkar
dc.contributor.authorHaughey, Annika
dc.date.accessioned2021-11-03T09:06:34Z
dc.date.available2021-11-03T09:06:34Z
dc.date.created2018-10-24T15:03:03Z
dc.date.issued2018-08
dc.identifier.urihttps://hdl.handle.net/20.500.13015/2319
dc.descriptionAugust 2018
dc.descriptionSchool of Engineering
dc.description.abstractFlow control, in general, is less effective in the presence of a swept crossflow when compared with an unswept case. Detailed SPIV measurements were acquired in order to investigate the flow physics as to why this performance drop occurs. Time-averaged velocity iso-surfaces were collected closer to the surface directly behind the active jet, which was indicative of the jet’s effect. This so called “trench” extended perpendicular to the orifice for the unswept case, and was reduced in area, and followed a swept trajectory for the swept case.
dc.description.abstractStereo particle image velocimetry was used to investigate the flow physics of these orifices more closely. Vortical structures were created by each orifice, the trapezoid and triangle orifice geometries resulted in vectoring of these structures toward the larger cross-sectional area of the shape. Axis-switching was observed by each orifice; however, it occurred closer to the orifice for the triangle and trapezoid case when compared to the rectangular orifice. Jet spreading and dissipation were also investigated and these quantities were highly dependent on the orifice geometry.
dc.description.abstractThese conclusions led to the second part of this study, which was an investiga-tion into the effect of orifice geometry on the vortical structures associated with a synthetic jet in order to achieve better performance in the presence of swept crossflows. Six orifices with varying aspect ratios, areas, and geometries were tested with a single hotwire to obtain the spanwise distribution of the velocity at the jet orifice plane. The trapezoid and triangle orifices (which had equal area to a rectangular case) were chosen for further testing based on their vectored and asymmetric velocity distribution.
dc.description.abstractThese data give insight into the interactions of the jet with the swept and un-swept crossflow, which could explain the decrease in performance in the swept cases. These data suggest that the swept crossflow eliminates the inboard side of the vortical structure created by the jet, which could account for the decrease in performance. In order to increase the performance of synthetic jets in swept crossflow it could be benefi-cial to manipulate the orifice geometry in order to strengthen one side of these vortical structures to overcome the swept crossflow.
dc.description.abstractVortical structures were seen emanating from the orifice; these structures consist-ed of two large rings created from the finite edges of the orifice and a pinched middle. For the unswept case, this ring travels downstream directly perpendicular to the orifice and dissipates symmetrically about the centerline. With the addition of sweep, a similar structure is observed emanating from the orifice, however the swept crossflow quickly takes effect and weakens the inboard side of the structure. As this structure travels downstream, it follows the trajectory of the swept flow and dissipates asymmetrically, and the inboard ring is significantly reduced in size at the edge of the measurement domain.
dc.description.abstractFlow control has been a topic of interest for many years now and significant advances have been made in achieving a level of technology readiness for a variety of applications. This study aims to conduct an investigation of the effect of a variety of parameters on the performance of synthetic jets applied as flow control devices on a vertical tail. An interchangeable airfoil model was designed to allow for a variation in chosen parameters. These parameters were: spanwise spacing of actuators, chordwise placement of actuators, sweep angle, control surface deflection angle, and control surface chord. This study investigates the effect of a variation in sweep angle and includes future designs for a variation in control surface chord.
dc.language.isoENG
dc.publisherRensselaer Polytechnic Institute, Troy, NY
dc.relation.ispartofRensselaer Theses and Dissertations Online Collection
dc.subjectAeronautical engineering
dc.titleSynthetic jet-based flow control in the presence of a three-dimensional crossflow
dc.typeElectronic thesis
dc.typeThesis
dc.digitool.pid179409
dc.digitool.pid179410
dc.digitool.pid179411
dc.rights.holderThis electronic version is a licensed copy owned by Rensselaer Polytechnic Institute, Troy, NY. Copyright of original work retained by author.
dc.description.degreeMS
dc.relation.departmentDept. of Mechanical, Aerospace, and Nuclear Engineering


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record