Mechanistic study of noise source and propagation characteristics of flow noise of a submarine

Ocean Engineering, Journal Year: 2024, Volume and Issue: 302, P. 117667 - 117667

Published: April 1, 2024

Language: Английский

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Steady and dynamic load measurements over a generic submarine hull form with various appendage configurations

Proceedings of the Institution of Mechanical Engineers Part M Journal of Engineering for the Maritime Environment, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 19, 2025

Experimental studies for the steady and dynamic loads over a generic submarine hull form ( SUBOFF) with various appendage configurations in submerged motion was investigated through scaled model tests High Speed Towing Tank facility at Naval Science & Technological Laboratory, India. Steady load measurements were performed range of angles incidence angle attack (± 35°) drift (0° to including control surface deflections 20°). Measurements both vertical horizontal plane oscillating frequencies ranging from 0.21 0.55 Hz. The carried out four different SUBOFF comprising bare hull, sail, fins fully appended hull. aim present study is gather force/moment data, estimate hydrodynamic coefficients, validate extend such data wide operation scenarios experienced by high incidence. particulars model, experimental measurement technique, test results estimated coefficients are highlighted paper. generated above will greatly complement current research on characteristics bodies computationally experimentally.

Language: Английский

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Numerical analysis of the far wake flow behind a submarine with full appendages

Proceedings of the Institution of Mechanical Engineers Part M Journal of Engineering for the Maritime Environment, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 21, 2025

Wake flow behind underwater vehicles such as submarines was widely researched with its impacts on propulsion or antisubmarine technology. Extensive research performed the near wake for hydrodynamics of propulsion, but far given less attention owing to huge challenges and expensive costs. In this study, a long-range evolution full-size Suboff submarine full appendages is numerically investigated by Delayed Detached Eddy Simulation (DDES) method, which provides reference shape design detection. Evolution vortex structures sail tail detailed, including modes horseshoe vortex, hairpin tip vortex. The diffusion along at specific speed also focused, using slice analysis vorticity velocity. When dimensionless velocity profiles in different slices are stacked up, overlay shows pretty coincident contour deficit submarine. equations range fitted orthogonal distance regression principle further application.

Language: Английский

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Numerical Simulation of Flow Around a Submarine Under the Rudder Deflection Condition Based on Different Turbulence Models

Lecture notes in civil engineering, Journal Year: 2025, Volume and Issue: unknown, P. 422 - 432

Published: Jan. 1, 2025

Language: Английский

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Three-dimensional configuration optimization of X semi-dynamic rudder for fully appended AUV based on response surface methodology and NSGA-II

Ocean Engineering, Journal Year: 2025, Volume and Issue: 329, P. 121107 - 121107

Published: April 8, 2025

Language: Английский

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Numerical investigation on the influence of free surface on the hydrodynamic and wake characteristics of submarine

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(7)

Published: July 1, 2024

In the process of movement, submarine inevitably involves free surface navigation, such as floating observation, suction power generation, and rescue. Under various circumstances, interaction between leads to complex flow fields wakes, which affects its hydrodynamic performance. this study, a three-dimensional numerical model considering influence is established. The volume-of-fluid with an artificial compression term used capture gas–liquid interface, unsteady field hydrodynamics are predicted using shear stress transport k–ω turbulence model. Based on analysis mesh convergence reliability, performance wake characteristics submarines under different submergence depths were studied. results show that has significant resistance, wave wake, field, vortex structure submarine, closely related depth. Compared infinite depth, total resistance near increases by 159.2%, mainly due pressure resistance. system generated hull will directly affect distribution structure. As depth increases, effect gradually weakens, it can be ignored when more than 4 times diameter hull.

Language: Английский

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Effects of pitch angle on a near free surface underwater vehicle

Ocean Engineering, Journal Year: 2023, Volume and Issue: 286, P. 115611 - 115611

Published: Aug. 14, 2023

Simulations of an underwater vehicle were conducted to investigate the effects steady pitch angle, Froude number, and submergence depth. A shallow submerged (D* = 1.1) a deeply 6.6) SUBOFF was investigated over range angles numbers. Results show that proximity free surface causes increased resistance, heave moment diminish rapidly with Even though D* 3.3 is typically quoted as being threshold, can still be observed especially at large angles. At asymmetry seen between pressure distribution upper lower surfaces SUBOFF, phase shift hydrodynamic forces moments. smaller angles, changes in moments stay relatively linear offset from zero degrees. larger become non-linear due crossflow separation air entrainment bow/stern. Additionally, potential stern planes cope investigated, showing safety threshold respect depth, hull angle.

Language: Английский

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Assessment of Numerical Captive Model Tests for Underwater Vehicles: The DARPA SUB-OFF Test Case

Journal of Marine Science and Engineering, Journal Year: 2023, Volume and Issue: 11(12), P. 2325 - 2325

Published: Dec. 8, 2023

During the early design stage of an underwater vehicle, correct assessment its manoeuvrability is a crucial task. Conducting experimental tests still has high costs, especially when dealing with small vehicles characterized by low available budget. In current investigation, virtual towing tank are simulated using open-source OpenFOAM library in order to assess reliability CFD methods for prediction hydrodynamic forces and moments. A well-known case study, Defence Advanced Research Projects Agency (DARPA) SUB-OFF model, used, outcomes compared results literature. Five different configurations investigated pure drift tests, rudder rotation both vertical horizontal plane. The show overall good agreement data quite demanding mesh arrangement 3M cells, favourable balance between accuracy computational time. more detail, expected error most significant during manoeuvres less than 2% fully appended configuration (the submarine real operative condition), whereas moderately reduced barehull (a not representative hull) 15%. possible reason differences observed could be attributed description two streamwise vortices generated manoeuvring. Apart from lateral force yaw moment, longitudinal also presented, having greater disparity data. Nevertheless, no important role purpose making stability control predictions. study contributes validation consolidation methods, offering insights into their limitations practical applications vehicles.

Language: Английский

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CFD Investigation of Hydrodynamic Force and Moment Acting on Stern-Rudder Plane Configurations of a Submarine

Published: April 7, 2024

The paper presents the prediction of hydrodynamic characteristics different rudder -plane configurations behind a submarine in deep water through Reynolds-Averaged Navier-Stokes method Ansys Fluent Solver. force and moment acting on Cross-plane, X-plane, Y-plane are analyzed for estimating coefficientsfor predicting advantages each configuration to control ship. obtained results show that X-force X-plane is larger than Cross-plane configurations. However, Y-force, Z-force significantly greater Y-force left same tendency can be seen about y-axis z-axis. roll induced by case configuration.

Language: Английский

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Numerical investigation of the flow noise of an underwater vehicle

Journal of Physics Conference Series, Journal Year: 2024, Volume and Issue: 2756(1), P. 012002 - 012002

Published: May 1, 2024

Abstract Flow noise is an important issue of underwater vehicles. In this paper, the ability different numerical methods to predict flow DARPA SUBOFF vehicle model investigated and compared. It found that front command deck tail fins are main sources. Numerical results show delayed detached eddy simulation a suitable computational for simulations.

Language: Английский

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