Study on the propeller wake dynamics using multiscale proper orthogonal decomposition

Physics of Fluids, Год журнала: 2025, Номер 37(1)

Опубликована: Янв. 1, 2025

Reduced-order analysis is employed to comprehend and elucidate the dominant spatiotemporal turbulent structures that play a pivotal role in evolution of propeller wake dynamics. The vortices encompasses cyclical process from stability instability as well multiscale progression coherence disintegration. Consequently, this paper utilizes proper orthogonal decomposition (mPOD) model investigate dynamic characteristics under various conditions simulated via delayed detached-eddy simulation method. findings are then compared with data obtained through (POD). comparison results experimental data, along grid convergence study, confirms reliability numerical outputs used inputs for modal analysis. indicate frequency components associated flow modes mPOD relatively singular, which facilitates better explanation phenomena elucidates underlying mechanisms. encompass contributing at different scales during wake. In addition, destabilization mechanisms wakes loading also elaborated based on reduced-order

Язык: Английский

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Investigation on the influence of the transverse jet on a self-propelled submarine

Ocean Engineering, Год журнала: 2025, Номер 324, С. 120745 - 120745

Опубликована: Фев. 26, 2025

Язык: Английский

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High-fidelity modeling of cavitating flow around a marine propeller with bio-inspired wavy rudder configurations: Radiated noise analysis using hydro-acoustic analogies

Physics of Fluids, Год журнала: 2025, Номер 37(3)

Опубликована: Март 1, 2025

This study implements high-fidelity modeling to analyze the hydrodynamic and hydroacoustic characteristics of bio-inspired marine vessel rudders, modeled after fins a humpback whale. The focus is on tubercled leading-edge rudders (TLER), with an amplitude 5% wavelengths 25% 50% mean chord length, compared straight rudder. Simulations are performed at deflection angles α = 0°, 10°, 20° using large Eddy simulation turbulence model Schnerr–Sauer cavitation model, in conjunction volume fluid cavity tracker, combined Ffowcs Williams-Hawkings analogy within OpenFOAM framework. goal optimize propulsion system reduce radiated noise from propeller/rudder under conditions. examines impact flow dynamics parameters such as sound pressure level, thrust, acoustic spectrum levels, rudder force, separation/spanwise flow. Key focuses include formation, development, dissipation dominant wake morphologies—such spiral tip, root, hub, propeller, trailing edge vortices—and features, including sheet, tip along propeller surface, well surface cavitation. Interactions between these generation mechanisms, their identified frequency modes examined for various TLER designs maneuvering conditions improve efficiency. Phenomena, counter-rotating vortex pairs, low-pressure zones, separation, reattachment near TLER, short-wave instabilities, breakdown, pairing mutual inductance, progressive weakening, minor meandering, analyzed across low-, medium-, high-frequency ranges narrow-band broadband spectral characteristics.

Язык: Английский

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Comparison study of the vortical structures in the wake of a rim-driven thruster and a ducted propeller in bollard conditions

Ocean Engineering, Год журнала: 2024, Номер 306, С. 118064 - 118064

Опубликована: Май 14, 2024

Язык: Английский

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Large-eddy simulation of flow noise from turbulent flows past an axisymmetric hull using high-order schemes

Ocean Engineering, Год журнала: 2024, Номер 312, С. 119150 - 119150

Опубликована: Сен. 5, 2024

Язык: Английский

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Assessment of the Reynolds-stress model-based hybrid RANS/LES method for junction flow around a fully appended underwater vehicle

Ocean Engineering, Год журнала: 2024, Номер 318, С. 120073 - 120073

Опубликована: Дек. 21, 2024

Язык: Английский

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Bio-inspired profile improving the flow near the stern of an underwater vehicle

Ocean Engineering, Год журнала: 2024, Номер 314, С. 119693 - 119693

Опубликована: Ноя. 8, 2024

Язык: Английский

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