logo-ri

Repositório Institucional da Produção Científica da Marinha do Brasil (RI-MB)

Use este identificador para citar ou linkar para este item: https://www.repositorio.mar.mil.br/handle/ripcmb/846481
Registro completo de metadados
Campo DCValorIdioma
dc.contributor.advisorRadko, Timourpt_BR
dc.contributor.advisorBrown, Justin M.pt_BR
dc.contributor.authorNadaf, Elias de Castro-
dc.date.accessioned2023-12-07T13:46:35Z-
dc.date.available2023-12-07T13:46:35Z-
dc.date.issued2022-
dc.identifier.urihttps://www.repositorio.mar.mil.br/handle/ripcmb/846481-
dc.descriptionThis study aims to explore the behavior of turbulent wakes generated by a spherical submerged body propagating with constant speed in a non-uniformly stratified fluid. The investigation is based on a series of high-resolution numerical simulations in which the background stratification is systematically varied. We consider one linear and five non-linear temperature profiles and two sets of Froude numbers (Fr), Fr = 1.0 and Fr = 3.2. The analysis of dissipation of thermal variance (χ) shows that the shape of the wake for non-uniform profiles is more horizontally spread, and internal waves are much stronger than in linear stratification. Experiments with Fr = 1.0 show a rather asymmetric energy distribution caused by internal wave reflections from low-gradient regions. An idealized model demonstrates that internal waves emitted at horizontal angles shallower than roughly 64 degrees are reflected. For Fr = 3.2, internal waves are radiated at steeper angles and transmitted more. Using decay rates of χ, the maximum detection time of the wake can be estimated, showing that for Fr = 3.2, the thermal signal lasts four to five times longer than for Fr = 1.0. Furthermore, concave profiles produce signals lasting approximately twice as long as those for linear profiles, whereas low-gradient types have half the duration. This research is expected to assist in the development of non-traditional detection algorithms for undersea warfare.pt_BR
dc.language.isoenpt_BR
dc.publisherNaval Postgraduate School (NPS), Monterey, EUApt_BR
dc.rightsopenAccesspt_BR
dc.subjectWake dynamicspt_BR
dc.subjectStratificationpt_BR
dc.subjectSubmarine detectionpt_BR
dc.titleExploring turbulent wakes in a non-uniformly stratified environment for submarine detectionpt_BR
dc.typedoctoralThesispt_BR
dc.subject.dgpmOceanografia físicapt_BR
Aparece nas coleções:Hidrografia e Navegação: Coleção de Teses

Arquivos associados a este item:
Arquivo Descrição TamanhoFormato 
THESIS_Nadaf_Elias.pdf2,17 MBAdobe PDFVisualizar/Abrir
Mostrar registro simples do item Visualizar estatísticas


Os itens no repositório estão protegidos por copyright, com todos os direitos reservados, salvo quando é indicado o contrário.