Shape optimisation of an integrated bulb-keel

dc.contributorAalto-yliopistofi
dc.contributorAalto Universityen
dc.contributor.advisorLarsson, Lars
dc.contributor.advisorVesting, Florian
dc.contributor.advisorOrych, Michal
dc.contributor.authorLjungqvist, Kasper
dc.contributor.departmentSovelletun mekaniikan laitosfi
dc.contributor.schoolInsinööritieteiden korkeakoulufi
dc.contributor.schoolSchool of Engineeringen
dc.contributor.supervisorMatusiak, Jerzy
dc.date.accessioned2020-12-23T17:33:14Z
dc.date.available2020-12-23T17:33:14Z
dc.date.issued2011
dc.description.abstractThe objective of the thesis was to shape optimise an integrated bulb-keel using a numerical optimisation method and to validate how well the used methods suit this kind of problem. The algorithm used for the optimisation was a Non-dominated Sorting Genetic Algorithm, NSGA-II. The optimisation was limited to the bulb part of the keel and 7 design variables were used together with 4 inequality constraints. The hydrodynamic performance of the keel was evaluated using a RANS viscous solver and the objective function used in the optimisation was the ratio of drag coefficient over lift coefficient CD/CL. The numerical CFD calculations were validated with experimental wind tunnel tests, which is a crucial part when investigating new types of numerical flow problems. The CFD calculations were also verified using a Least Square Root method in order to obtain the numerical uncertainty. The comparison between the wind tunnel results and the CFD results showed that the CL/CD -ratio was predicted very similarly for the numerical and experimental tests. The optimised keel design had a CD/CL-ratio improvement of around 4% compared to the initial keel design. Finally the keels were mounted on a hull of a 40-foot yacht and tested in a velocity prediction program (VPP) in order to get a more understandable performance indicator of the keels.en
dc.format.extent89 + [20]
dc.identifier.urihttps://aaltodoc.aalto.fi/handle/123456789/99450
dc.identifier.urnURN:NBN:fi:aalto-2020122358277
dc.language.isoenen
dc.programme.majorLaivanrakennusoppifi
dc.programme.mcodeKul-24fi
dc.rights.accesslevelclosedAccess
dc.subject.keywordkeelen
dc.subject.keywordbulben
dc.subject.keywordNSGA-IIen
dc.subject.keywordoptimisationen
dc.subject.keywordCFDen
dc.subject.keywordRANSen
dc.subject.keywordintegrated bulb-keelen
dc.titleShape optimisation of an integrated bulb-keelen
dc.titleFormoptimering av en integrerad bulbkölsv
dc.type.okmG2 Pro gradu, diplomityö
dc.type.ontasotMaster's thesisen
dc.type.ontasotPro gradu -tutkielmafi
dc.type.publicationmasterThesis
local.aalto.digiauthask
local.aalto.digifolderAalto_92329
local.aalto.idinssi42756
local.aalto.openaccessno

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