Modeling and Simulation on Fluid Dynamic Depth-Setting TUV Based on FLUENT

2011 ◽  
Vol 314-316 ◽  
pp. 1676-1681
Author(s):  
Guo Hua Xu ◽  
Xiong Shen ◽  
Kun Yu
Keyword(s):  
Complex Shape ◽  
Empirical Equation ◽  
Fluid Dynamic ◽  
Hydrodynamic Characteristic ◽  
Underwater Vehicles ◽  
The Body ◽  
Test Model ◽  
Remotely Operated Vehicle ◽  
Simulation Based ◽  
Distribute System

The prerequisite factors for the simulation and controlling of underwater vehicles are hydrodynamic coefficients, which we must measure accurately. In this paper, we took a complex shape remotely operated vehicle as the test model, and figured out the important coefficients that can be applicable for the open-shelf depth-setting TUV through a series of hydrodynamic tests. In order to boost the reliability of a depth-setting TUV system, we carry out numerical simulation and hydrodynamics method on the body of the TUV through the Dynamic Analysis of a single rudder .Comparing with empirical equation, the method has be predicted a high accuracy in hydrodynamic characteristic prediction of depth-setting towed vehicle . After changing the experiment environment of the TUV as possible as we can, a suitability algorithm can be used on the distribute system. And then, the pre-design and later validation of TUV with the conclusion of the simulation based on FLUENT which contribute to shorter calculating period and lower economy could show better depth-setting consequent. The paper draw the Process of the Dynamic Depth-setting TUV for three parts including simulation of the rubber , algorithm experiment of the body and the experiment on TUV.

Designing of the body shape of an autonomous underwater vehicle using the design of experiments method

2018 ◽  
Vol 233 (18) ◽  
pp. 6307-6325
Author(s):  
Majid Alijani ◽  
Marhamat Zeinali ◽  
Nowrouz Mohammad Nouri
Keyword(s):  
Design Of Experiments ◽  
Drag Coefficient ◽  
Body Shape ◽  
Autonomous Underwater Vehicle ◽  
Autonomous Underwater Vehicles ◽  
Underwater Vehicle ◽  
Underwater Vehicles ◽  
The Body ◽  
Vehicle Body ◽  
Test Model

The process of designing autonomous underwater vehicles comprises several steps, including the designing of the body shape. The hydrodynamic designing of the body shape is a major step in designing the body of an underwater vehicle. The effective parameters in the hydrodynamic design of body shape include the lengths of nose and tail, nose and tail profiles, and also the dimensions of the blunt sections in front of the nose and behind the tail. In the present study, the design of experiments method has been employed to investigate the effect of each of the above parameters on the drag coefficient of an autonomous underwater vehicle body. For this purpose, in addition to introducing the body classes of the Hydrolab family of underwater vehicles, the numerical simulation results of fluid flow over the body of a Hydrolab500 AUV have been used for the design of experiments. In the first step, an experiment has been performed in water tunnel on a test model in order to validate the pressure profile for the body of Hydrolab500. The comparison between the empirical and numerical results related to Hydrolab500 body confirms the validity of the numerical approach used in this paper. The results of the present work show that the drag coefficient of an autonomous submersible in the final design can be accurately estimated with the help of the presented method.

scholarly journals Fish larvae exploit edge vortices along their dorsal and ventral fin folds to propel themselves

2016 ◽  
Vol 13 (116) ◽  
pp. 20160068 ◽  
Author(s):  
Gen Li ◽  
Ulrike K. Müller ◽  
Johan L. van Leeuwen ◽  
Hao Liu
Keyword(s):  
Larval Fish ◽  
Fish Larvae ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Reynolds Numbers ◽  
Bony Fish ◽  
The Body ◽  
Functional Explanation ◽  
Image Velocimetry ◽  
Median Fins

Larvae of bony fish swim in the intermediate Reynolds number ( Re ) regime, using body- and caudal-fin undulation to propel themselves. They share a median fin fold that transforms into separate median fins as they grow into juveniles. The fin fold was suggested to be an adaption for locomotion in the intermediate Reynolds regime, but its fluid-dynamic role is still enigmatic. Using three-dimensional fluid-dynamic computations, we quantified the swimming trajectory from body-shape changes during cyclic swimming of larval fish. We predicted unsteady vortices around the upper and lower edges of the fin fold, and identified similar vortices around real larvae with particle image velocimetry. We show that thrust contributions on the body peak adjacent to the upper and lower edges of the fin fold where large left–right pressure differences occur in concert with the periodical generation and shedding of edge vortices. The fin fold enhances effective flow separation and drag-based thrust. Along the body, net thrust is generated in multiple zones posterior to the centre of mass. Counterfactual simulations exploring the effect of having a fin fold across a range of Reynolds numbers show that the fin fold helps larvae achieve high swimming speeds, yet requires high power. We conclude that propulsion in larval fish partly relies on unsteady high-intensity vortices along the upper and lower edges of the fin fold, providing a functional explanation for the omnipresence of the fin fold in bony-fish larvae.

scholarly journals Research on the Undulatory Motion Mechanism of Seahorse Based on Dynamic Mesh

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Xinyu Quan ◽  
Ximing Zhao ◽  
Shijie Zhang ◽  
Jie Zhou ◽  
Nan Yu ◽  
...  
Keyword(s):  
Design Method ◽  
Fluid Dynamic ◽  
Underwater Vehicles ◽  
Dynamic Mesh ◽  
Driving Mechanism ◽  
Optimized Design ◽  
Motion Mechanism ◽  
Dorsal Fin ◽  
Propulsion Performance ◽  
Fluent Software

The seahorse relies on the undulatory motion of the dorsal fin to generate thrust, which makes it possess quite high maneuverability and efficiency, and due to its low volume of the dorsal fin, it is conducive to the study of miniaturization of the driving mechanism. This paper carried out a study on the undulatory motion mechanism of the seahorse’s dorsal fin and proposed a dynamic model of the interaction between the seahorse’s dorsal fin and seawater based on the hydrodynamic properties of seawater and the theory of fluid-structure coupling. A simulation model was established using the Fluent software, and the 3D fluid dynamic mesh was used to study the undulatory motion mechanism of the seahorse’s dorsal fin. The effect of the swing frequency, amplitude, and wavelength of the seahorse’s dorsal fin on its propulsion performance was studied. On this basis, an optimized design method was used to design a bionic seahorse’s dorsal fin undulatory motion mechanism. The paper has important guiding significance for the research and miniaturization of new underwater vehicles.

scholarly journals Analysis of Effect of Bulbous Bow Shape to Ship Resistance in Catamaran Boat

2018 ◽  
Vol 159 ◽  
pp. 02058
Author(s):  
Deddy Chrismianto ◽  
Kiryanto ◽  
Berlian Arswendo Adietya
Keyword(s):  
Fluid Dynamic ◽  
The Body ◽  
Wave System ◽  
Total Resistance ◽  
Factors Affecting ◽  
Ship Resistance ◽  
Bow Wave ◽  
Main Factors ◽  
The One ◽  
Bulbous Bow

Ship resistance is one of the main factors affecting the design of a ship. Catamaran boat is a ship with small wet surface area that able to reduce drag and improve ship power. Generally, a bulbous bow is implemented to reduce wave resistance because the bulbous shape is believed to attenuate the bow wave system. Additionally, the bulbous bow also tends to reduce viscous resistance. When the flow around the body is smooth, the total ship resistance can be reduced significantly if the optimum bulbous bow is obtained. In this study, the main purpose is to get the bulbous bow shape in catamaran boat which produces the smallest ship resistance by using computational fluid dynamic (CFD). Generating the variation of the bulbous bow shapes apply the one-to-one correspondence of the cross section parameter (ABT) and lateral parameter (ABL). The result of investigation shows that application of bulbous bow on catamaran boat can reduce about 11-13% of total resistance of ship.

scholarly journals 3D Perfusable Hydrogel Recapitulating the Cancer Dynamic Environment to in Vitro Investigate Metastatic Colonization

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2467
Author(s):  
Chiara Vitale ◽  
Arianna Fedi ◽  
Alessandra Marrella ◽  
Gabriele Varani ◽  
Marco Fato ◽  
...  
Keyword(s):  
Single Channel ◽  
Fluid Dynamic ◽  
Dynamic Environment ◽  
Metastatic Breast ◽  
Polymeric Matrix ◽  
The Body ◽  
Secondary Site ◽  
Circulation System ◽  
Metastatic Cascade

Metastasis is a dynamic process involving the dissemination of circulating tumor cells (CTCs) through blood flow to distant tissues within the body. Nevertheless, the development of an in vitro platform that dissects the crucial steps of metastatic cascade still remains a challenge. We here developed an in vitro model of extravasation composed of (i) a single channel-based 3D cell laden hydrogel representative of the metastatic site, (ii) a circulation system recapitulating the bloodstream where CTCs can flow. Two polymers (i.e., fibrin and alginate) were tested and compared in terms of mechanical and biochemical proprieties. Computational fluid-dynamic (CFD) simulations were also performed to predict the fluid dynamics within the polymeric matrix and, consequently, the optimal culture conditions. Next, once the platform was validated through perfusion tests by fluidically connecting the hydrogels with the external circuit, highly metastatic breast cancer cells (MDA-MB-231) were injected and exposed to physiological wall shear stress (WSS) conditions (5 Dyn/cm2) to assess their migration toward the hydrogel. Results indicated that CTCs arrested and colonized the polymeric matrix, showing that this platform can be an effective fluidic system to model the first steps occurring during the metastatic cascade as well as a potential tool to in vitro elucidate the contribution of hemodynamics on cancer dissemination to a secondary site.

scholarly journals Developing emotional intelligence and situational awareness through simulation coaching

2020 ◽  
Vol 8 (2) ◽  
pp. 13
Author(s):  
Mari Helena Salminen-Tuomaala
Keyword(s):  
Mental Health ◽  
Emotional Intelligence ◽  
Content Analysis ◽  
Qualitative Study ◽  
Child Protection ◽  
Situational Awareness ◽  
The Body ◽  
Healthcare Staff ◽  
Simulation Based ◽  
Teamwork Skills

Objective: To examine how simulation coaching affects emotional intelligence (EI) skills and situational awareness in social and healthcare staff of small and medium-sized enterprises.Methods: This qualitative study involved 36 mental health and child protection professionals in five enterprises. Following simulation-based coaching interventions centered around the development of EI and situational awareness, the participants wrote essays on their development. Inductive content analysis was used to analyze the body of material.Results: The participants found simulation coaching an effective method for learning EI, situational awareness and teamwork skills. They also considered the scenarios and shared reflections to be a form of work supervision.Conclusions: Simulation coaching offers potential for the development of EI and situational awareness in mental health and child protection professionals.

scholarly journals A Novel Neural Network-Based SINS/DVL Integrated Navigation Approach to Deal with DVL Malfunction for Underwater Vehicles

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Wanli Li ◽  
Mingjian Chen ◽  
Chao Zhang ◽  
Lundong Zhang ◽  
Rui Chen
Keyword(s):  
Neural Network ◽  
Autonomous Navigation ◽  
Underwater Vehicles ◽  
The Body ◽  
Doppler Velocity ◽  
Integrated Navigation ◽  
Body Frame ◽  
Short Term ◽  
The Neural Network ◽  
Nonlinear Autoregressive

A navigation grade Strapdown Inertial Navigation System (SINS) combined with a Doppler Velocity Log (DVL) is widely used for autonomous navigation of underwater vehicles. Whether the DVL is able to provide continuous velocity measurements is of crucial importance to the integrated navigation precision. Considering that the DVL may fail during the missions, a novel neural network-based SINS/DVL integrated navigation approach is proposed. The nonlinear autoregressive exogenous (NARX) neural network, which is able to provide reliable predictions, is employed. While the DVL is available, the neural network is trained by the body frame velocity and its increment from the SINS and the DVL measurements. Once the DVL fails, the well trained network is able to forecast the velocity which can be used for the subsequent navigation. From the experimental results, it is clearly shown that the neural network is able to provide reliable velocity predictions for about 200 s–300 s during DVL malfunction and hence maintain the short-term accuracy of the integrated navigation.

scholarly journals Tracking Full-Body Motion of Multiple Fish with Midline Subspace Constrained Multicue Optimization

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Xiang Liu ◽  
Pei Ru Zhu ◽  
Ye Liu ◽  
Jing Wen Zhao
Keyword(s):  
Objective Function ◽  
Complex Shape ◽  
The Body ◽  
Body Motion ◽  
Sources Of Information ◽  
Dimensional Representation ◽  
Multiple Sources ◽  
Optimization Framework ◽  
Low Dimensional ◽  
Full Body

Capturing the body motion of fish has been gaining considerable attention from scientists of various fields. In this paper, we propose a method which is able to track the full-body motion of multiple fish with frequent interactions. We firstly propose to model the midline subspace of a fish body which gives a compact low-dimensional representation of the complex shape and motion. Then we propose a particle swarm-based optimization framework whose objective function takes into account multiple sources of information. The proposed multicue objective function is able to describe the details of fish appearance and is also effective through mutual occlusions. Excessive experimental results have demonstrated the effectiveness and robustness of the proposed method.

Investigation of the 3D Flow in Hemodialysis Venous Air Traps

2014 ◽  
Vol 553 ◽  
pp. 156-161
Author(s):  
Gholamreza Keshavarzi ◽  
Tracie J. Barber ◽  
Guan Heng Yeoh ◽  
Anne Simmons
Keyword(s):  
Fluid Dynamic ◽  
Waste Product ◽  
The Body ◽  
Flow Structures ◽  
Air Bubbles ◽  
Health Issues ◽  
3D Flow ◽  
Air Bubble ◽  
Different Types ◽  
Flow Phenomena

Hemodialysis is an extracorporeal system which removes the waste product from kidneys for patients with kidney failure. Air bubbles within the system can cause several deficiencies to the system, and more importantly serious health issues to the patients. Therefore, different types of air traps (artery and venous side) are situated in the setup to prevent air bubbles passing through the system and being sent to the body. There have been evidence of the air trap deficiency. In order to understand these deficiencies the flow inside these air traps need to be understood. The investigation of the flow structures in air traps allow us to predict the efficiency of the air traps in capturing the air bubbles and preventing them from passing through. Computational fluid dynamic (CFD) has been used to compare the flow inside both these air traps. The results show interesting flow phenomena leading to explanations of the air bubble capturing effect.

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