Hydroelasticity in Marine Hull Bottom Panels - Modeling and Characterization
2009 (English)Doctoral thesis, comprehensive summary (Other academic)
The work in this thesis is concerned with the localized problem of hydroelasticity in marine panel-water impacts with an overall aim to increase the eﬃciency of high-speed craft by application of more reﬁned methods in the structural design. The work mainly focuses on numerical modeling of the hydroelastic problem and therewith related aspects in the modeling and characterization of hydroelasticity. In addition, the work also addresses aspects regarding design methods of high-speed craft and experimental analysis of hydroelasticity.
Two-dimensional panel-water impacts are simulated by using the commercial ﬁnite element code LS-DYNA. For the modeling of the panel-water impact situations a generalized approach for determination of ﬂuid discretization and contact parameters is derived and extensively used throughout this work. The hydroelastic problem is studied through systematic series of numerical simulations regarding diﬀerent impact situations. The work advances the understanding of the hydroelastic problem and introduces concepts such as kinematic and inertia related hydroelastic eﬀects. The work further presents hydroelastic eﬀects in contrast to previously published results, in the sense that it may not be conservative to ignore hydroelasticity in the structural design. This increase in the structural response when accounting for hydroelasticity can partly be related to kinematic eﬀects, and partly to inertia related added mass eﬀects. The results further show that, the eﬀects of hydroelasticity increase with increased impact velocity, increased panel width, decreased deadrise angle, decreased panel ﬂexural and in-plane stiﬀness, and decreased rotational and in-plane ﬁxation at the boundaries.
A tentative method is derived to characterize the hydroelastic problem, which, despite its simplicity and limitations, is found to successfully capture the complexity of the hydroelastic interaction in the design of the experimental setup. The experimental water slam testing of composite hull panels are conducted to study the eﬀect of hydroelasticity for panels with diﬀerent stiﬀnesses. The observed hydroelastic eﬀects included changes in panel geometry, local velocity and hydrodynamic pressures. These eﬀects also correlate with the observed hydroelastic eﬀects from the numerical simulations.
Place, publisher, year, edition, pages
Stockholm: KTH , 2009. , xi, 20 p.
Trita-AVE, ISSN 1651-7660 ; 2009:42
ﬂuid-structure interaction, hydroelasticity, hull-water impact, high-speed craft, slamming, explicit ﬁnite element methods
IdentifiersURN: urn:nbn:se:kth:diva-10903ISBN: 978-91-7415-389-7OAI: oai:DiVA.org:kth-10903DiVA: diva2:229405
2009-09-16, F3, Lindstedtsvägen 26, KTH, Stockholm, 10:15 (English)
Temarel, Pandeli, Professor
Zenkert, Dan, Professor
QC 201008102009-09-022009-08-122010-08-10Bibliographically approved
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