Active and Passive Flow Control over the Flight Deck of Small Naval Vessels

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dc.contributor.authorShafer, Daniel Manfreden
dc.contributor.committeechairMason, William H.en
dc.contributor.committeememberDevenport, William J.en
dc.contributor.committeememberFindlay, David B.en
dc.contributor.departmentAerospace and Ocean Engineeringen
dc.date.accessioned2014-03-14T20:35:49Zen
dc.date.adate2005-05-16en
dc.date.available2014-03-14T20:35:49Zen
dc.date.issued2005-04-27en
dc.date.rdate2005-05-16en
dc.date.sdate2005-05-09en
dc.description.abstractHelicopter operations in the vicinity of small naval surface vessels often require excessive pilot workload. Because of the unsteady flow field and large mean velocity gradients, the envelope for flight operations is limited. This experimental investigation uses a 1:144 scale model of the U.S. Navy destroyer DDG-81 to explore the problem. Both active and passive flow control techniques were used to improve the flow field in the helicopter's final decent onto the flight deck. Wind tunnel data was collected at a set of grid points over the ship's flight deck using a single component hotwire. Results show that the use of porous surfaces decreases the unsteadiness of the flow field. Further improvements are found by injecting air through these porous surfaces, causing a reduction in unsteadiness in the landing region of 6.6% at 0 degrees wind-over-deck (WOD) and 8.3% at 20 degrees WOD. Other passive configurations tested include fences placed around the hangar deck edges which move the unsteady shear layer away from the flight deck. Although these devices cause an increase in unsteadiness downstream of the edge of the fence when compared to the baseline, the reticulated foam fence caused an overall decrease in unsteadiness in the landing region of 12.1% at 20 degrees WOD.en
dc.description.degreeMaster of Scienceen
dc.identifier.otheretd-05092005-165137en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-05092005-165137/en
dc.identifier.urihttp://hdl.handle.net/10919/32427en
dc.publisherVirginia Techen
dc.relation.haspartthesis_final.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectbackward facing stepen
dc.subjectfrigate ship airwakeen
dc.subjectflow controlen
dc.subjecthelicopter/ship operationsen
dc.subjectairwakeen
dc.titleActive and Passive Flow Control over the Flight Deck of Small Naval Vesselsen
dc.typeThesisen
thesis.degree.disciplineAerospace and Ocean Engineeringen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

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