A numerical study of target flow field detection by autonomous underwater vehicles

2020 ◽  
pp. 1-8
Author(s):  
Yixin Li ◽  
Le Zhang ◽  
Minge Zhang
Keyword(s):  
Flow Field ◽  
Numerical Study ◽  
Autonomous Underwater Vehicles ◽  
Underwater Vehicles ◽  
Field Detection

scholarly journals Numerical Study of the Effect of Wing Position on the Dynamic Motion Characteristics of an Underwater Glider

2021 ◽  
Vol 28 (2) ◽  
pp. 4-17
Author(s):  
Xiangcheng Wu ◽  
Pengyao Yu ◽  
Guangzhao Li ◽  
Fengkun Li
Keyword(s):  
Numerical Study ◽  
Autonomous Underwater Vehicles ◽  
Underwater Vehicles ◽  
Underwater Glider ◽  
Dynamic Motion ◽  
Biological Oceanography ◽  
Underwater Gliders ◽  
Movement Performance ◽  
Motion Characteristics ◽  
The Relationship

Abstract Underwater gliders are winged, autonomous underwater vehicles that are broadly applied in physical and biological oceanography. The position of the wing has an important effect on the movement performance of the underwater glider. In this paper, the dynamic motion of a series of underwater glider models with different longitudinal wing positions are simulated, which provides guidance for the design of underwater gliders. The results show that when the net buoyancy is constant, the wing position affects the gliding angle, but does not affect the relationship between the gliding angle and the gliding speed. In addition, the farther the wing position of the glider is from the buoyancy centre, the longer it takes for the attitude of a glider to change, whether the wing is in front of, or behind, the buoyancy centre.

Experimental and Numerical Study on Propulsive Performance of AUV

2010 ◽  
Author(s):  
Hiroyoshi Suzuki ◽  
Tomoya Inoue ◽  
Yoshitaka Watanabe ◽  
Hiroshi Yoshida ◽  
Risa Kitamoto ◽  
...  
Keyword(s):  
Numerical Study ◽  
Autonomous Underwater Vehicles ◽  
Underwater Vehicles ◽  
Long Distance ◽  
Hull Form ◽  
Océanographic Survey ◽  
Resistance Performance ◽  
Resistance Form ◽  
The Relationship ◽  
Mass Form

Recently, several underwater vehicles (UVs) including autonomous underwater vehicles (AUVs) and remotely operated vehicles (ROVs) have been developed. The purpose that such UVs are applied is various and the required performance for the UVs are also various. For example, they are oceanographic survey with long-distance cruising, plankton investigatory with high maneuverability and so on. Therefore, suitable UV for the mission is should be designed. In the above examples, UV that has the low resistance form is suitable for long-distance cruising; UV with low added mass form is suitable for plankton investigatory. Form the above viewpoint; we began working on a project to improve the UV’s hull form. Firstly, we focus on the resistance performance of UV within the resistance performance and maneuverability of UV. Using experimental and numerical methods, the relationship between the resistance performance and the UV’s hull form are investigated. In this paper, the part of the above results is introduced.

scholarly journals Motion tomography: Mapping flow fields using autonomous underwater vehicles

2017 ◽  
Vol 36 (3) ◽  
pp. 320-336 ◽  
Author(s):  
Dongsik Chang ◽  
Wencen Wu ◽  
Catherine R Edwards ◽  
Fumin Zhang
Keyword(s):  
Flow Field ◽  
Computerized Tomography ◽  
Autonomous Underwater Vehicles ◽  
Underwater Vehicles ◽  
Motion Integration ◽  
Integration Error ◽  
Vehicle Trajectories ◽  
Imperfect Knowledge ◽  
Field Estimation ◽  
Non Parametric

Since the motion of autonomous underwater vehicles is affected by ambient flow, knowledge of an environmental flow field can be used to improve the navigation of autonomous underwater vehicles. Due to imperfect knowledge of flow, the actual trajectory of an autonomous underwater vehicle deviates from the predicted trajectory. The difference between the actual and predicted trajectories is referred to as the motion-integration error, providing information of flow along the vehicle trajectory. Inspired by computerized tomography, this paper proposes motion tomography, a tomographic method for creating a fine-grid spatial map of flow based on the motion-integration error. While typical computerized tomography is a linear problem, motion tomography is a nonlinear problem because of unknown nonlinear trajectories of autonomous underwater vehicles and the dependency of the trajectories on the flow field. Therefore, motion tomography employs an iterative process consisting of two alternating steps: Trajectory tracing and flow field estimation. Starting from an initial guess of the flow field, in the trajectory tracing step, unknown nonlinear vehicle trajectories are estimated. Then, using the estimated vehicle trajectories, a spatial map of flow is constructed through either the non-parametric or parametric flow field estimation. The error bound for trajectory tracing is computed and the convergence of both the non-parametric and parametric flow field estimation algorithms is proved. Simulation and experimental data are analyzed to evaluate the performance of motion tomography when subject to changing vehicle speed and flow variability.

Numerical Study of the Combined Free-Forced Convection and Mass Transfer Flow Past a Vertical Porous Plate in a Porous Medium with Heat Generation and Thermal Diffusion

2006 ◽  
Vol 11 (4) ◽  
pp. 331-343 ◽  
Author(s):  
M. S. Alam ◽  
M. M. Rahman ◽  
M. A. Samad
Keyword(s):  
Mass Transfer ◽  
Flow Field ◽  
Differential Equations ◽  
Forced Convection ◽  
Heat Generation ◽  
Numerical Study ◽  
Porous Plate ◽  
Integration Scheme ◽  
Suction Parameter ◽  
Transfer Flow

The problem of combined free-forced convection and mass transfer flow over a vertical porous flat plate, in presence of heat generation and thermaldiffusion, is studied numerically. The non-linear partial differential equations and their boundary conditions, describing the problem under consideration, are transformed into a system of ordinary differential equations by using usual similarity transformations. This system is solved numerically by applying Nachtsheim-Swigert shooting iteration technique together with Runge-Kutta sixth order integration scheme. The effects of suction parameter, heat generation parameter and Soret number are examined on the flow field of a hydrogen-air mixture as a non-chemical reacting fluid pair. The analysis of the obtained results showed that the flow field is significantly influenced by these parameters.

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