scholarly journals Performance and Feasibility Study of a Novel Automated Catch-Hauling Device Using a Flexible Hose Net Structure in Set-Net

2021 ◽  
Vol 9 (9) ◽  
pp. 1015
Author(s):  
Qiao Li ◽  
Yue Li ◽  
Shuchuang Dong ◽  
Yoichi Mizukami ◽  
Jialin Han ◽  
...  
Keyword(s):  
Feasibility Study ◽  
Buoyancy Force ◽  
Airflow Rate ◽  
Water Tank ◽  
Flexible Hose ◽  
Opposite Edge ◽  
Lower Efficiency ◽  
Live Fish ◽  
Lower Productivity ◽  
Motion Parameters

The labor-intensive catch-hauling method in set-net fisheries faces problems of lower productivity, lower efficiency, and higher operational risk due to aging problem and labor insufficiency. To solve such problems, a novel catch-hauling device using the flexible fire hose and net (hose net), which is placed in the box chamber, was proposed in this study. The hoses were inflated with air injected into one edge of the hose net, and the buoyancy force increased: the net gradually floated up, cornering the fish in the opposite edge. To corner and harvest the fish efficiently and safely, the changing formation and motion parameters of the hose net are significant. A series of floating up, sinking experiments, and catch-hauling tests were conducted to evaluate the performance of this device. The results showed that the hose net could gradually float in an ideal form and sink smoothly through natural exhaust and stretched on the bottom of the water tank. The time spent and average speeds in floating and sinking processes varied with air pressure and airflow rate, allowing the hose net motion to be controlled in practice by adjusting the airflow. Through the catch-hauling test using live fish, most of the fish were directed into the fish bag. Two main capture failure phenomena were also observed. Overall, this newly developed automated catch-hauling device is expected to be successful for use in modern fisheries.

Experimental Study on the Motion of a Flexible Hose Net Used in Automated Net-Hauling System

2019 ◽  
Author(s):  
Yue Li ◽  
Yoichi Mizukami ◽  
Takero Yoshida ◽  
Qiao Li ◽  
Jialin Han ◽  
...  
Keyword(s):  
Buoyancy Force ◽  
Air Flow ◽  
Scale Model ◽  
Water Tank ◽  
Flexible Hose ◽  
Lower Efficiency ◽  
Practical Operation ◽  
Tank Experiment ◽  
Water Tank Experiment ◽  
Lower Production

Abstract In the set-net fishery, large amount of manpower is needed for hauling the box chamber to harvest fish. With aging problem and labor insufficiency, the labor-intensive net-hauling method faces the problems of lower production, lower efficiency and higher operational risk. An automated net-hauling system using the flexible hose net which is installed in the box chamber is being developed to solve such problems. With air injected from one edge of the hose net, the hoses are inflated and the buoyancy force increases, the net floats up gradually, cornering the fish in the other edge. To corner and harvest the fish efficiently and safely, the deformation and the motion parameters of the hose net are of significance. This paper presents the results of the water tank experiment using 1/6 scale model, which was conducted to analyze the deformation of the hose net with different volumes of air in, the time spent for floating up and sinking down and the average velocities of sinking and floating processes. The results showed that when the attached weight reached 42.5% of the maximum buoyancy force of the hose net, the net could float up gradually in an ideal form and sink down smoothly through natural exhaust and stretched on the bottom of the water tank. The time spent and average velocities in floating up and sinking down processes varied with air pressure and air flow rate, making it possible to control the motion of the hose net by adjusting the air flow in practical operation.

Feasibility Study of the Floating Axis Wind Turbine: Preliminary Model Experiments

2017 ◽  
Author(s):  
Hiromichi Akimoto ◽  
Kazuhiro Iijima ◽  
Yasuhiro Takata
Keyword(s):  
Wind Turbine ◽  
Feasibility Study ◽  
Vertical Axis ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Water Tank ◽  
Tank Model ◽  
Preliminary Model ◽  
Vertical Axis Turbine ◽  
The Stability

Floating Axis Wind Turbine is a concept of a floating vertical axis offshore wind turbine. In this design, a vertical axis turbine is directly mounted on a rotating spar buoy so that it does not require mechanical bearing supports of the heavy rotor. Multiple roller-generator units are on another small semi-sub float for extracting power from the rotating spar. A water tank model of 1/100 scale 5MW turbine and model power take-off units of about 1/20 scale are used for checking the concept. The results show the stability of the proposed turbine and demonstrates the function of roller-generator units.

Study of a Novel Air-augmented Waterjet Boost Concept

2014 ◽  
Vol 30 (01) ◽  
pp. 1-6 ◽  
Author(s):  
Alon Gany ◽  
Aviad Gofer
Keyword(s):  
Kinetic Energy ◽  
Airflow Rate ◽  
Water Tank ◽  
Static Tests ◽  
Pump Operation ◽  
Marine Propulsion ◽  
Analysis Experiment ◽  
Exhaust Jet ◽  
Propulsion Concept ◽  
Engine Power

This research presents analysis, experiment, and prediction of the performance of a unique marine propulsion concept, the air-augmented waterjet, having a revolutionary potential for significant thrust augmentation and boost capability of waterjet systems. So far, this concept has not been realized in any operational vessel. The air-augmented waterjet propulsion concept is similar to an after-burner in the aeronautical turbojet engine. The thrust augmentation results from the injection of air bubbles into the water flow, converting their expansion work òpdV into additional kinetic energy of the exhaust jet without affecting the pump operation. It can enable substantially augmenting boost capability, overcoming hump resistance, and increasing maximum attainable vessel speed while avoiding cavitation problems. Static tests at the Technion's water tank, using a jetski waterjet engine of a nominal power of 50 kW, have been conducted with and without air injection over a range of motor revolutions per minute (rpm). The addition of air increased the thrust by 20% to 50% depending on the airflow rate and engine rpm. Air expansion work increased the exhaust jet kinetic energy at an efficiency of 70% approximately. Based on the static experiments, prediction of the system behavior for different vessel speeds and engine power levels has been made, revealing a higher relative thrust augmentation for the same pump power and airflow rate at higher vessel speeds. The air-augmented waterjet concept may add a new dimension to marine propulsion as well as upgrade existing vessels.

Study of Damping Methods on Sloshing Reduction of Water Tank of Live Fish Transporting Vehicle Subjected to Horizontal Excitation

2018 ◽  
Vol 2018 (0) ◽  
pp. G1000401
Author(s):  
Daiki TANAKA ◽  
Atsuhiko SHINTANI ◽  
Tomohiro ITO ◽  
Chihiro NAKAGAWA ◽  
Munekazu MAEDA ◽  
...  
Keyword(s):  
Water Tank ◽  
Live Fish

Study of Damping Methods on Sloshing Reduction of Water Tank of Live Fish Transporting Vehicle Considering Road Running

2019 ◽  
Vol 2019.94 (0) ◽  
pp. P042
Author(s):  
Daiki TANAKA ◽  
Atsuhiko SHINTANI ◽  
Tomohiro ITO ◽  
Chihiro NAKAGAWA ◽  
Munekazu MAEDA ◽  
...  
Keyword(s):  
Water Tank ◽  
Live Fish

Study on Sloshing Reduction Method of Water Tank of Live Fish Transporting Vehicle

2019 ◽  
Vol 2019 (0) ◽  
pp. J10319P
Author(s):  
Daiki TANAKA ◽  
Atsuhiko SHINTANI ◽  
Tomohiro ITO ◽  
Chihiro NAKAGAWA ◽  
Munekazu MAEDA ◽  
...  
Keyword(s):  
Reduction Method ◽  
Water Tank ◽  
Live Fish

Autonomous Surgical Robotics Using 3-D Ultrasound Guidance: Feasibility Study

2007 ◽  
Vol 29 (4) ◽  
pp. 213-219 ◽  
Author(s):  
John Whitman ◽  
Matthew P. Fronheiser ◽  
Nikolas M. Ivancevich ◽  
Stephen W. Smith
Keyword(s):  
Feasibility Study ◽  
Ultrasound Guidance ◽  
3D Ultrasound ◽  
Surgical Robot ◽  
Water Tank ◽  
Robot Arm ◽  
Tissue Phantom ◽  
Array Transducer ◽  
Alignment Mark ◽  
Transducer Probe

The goal of this study was to test the feasibility of using a real-time 3D (RT3D) ultrasound scanner with a transthoracic matrix array transducer probe to guide an autonomous surgical robot. Employing a fiducial alignment mark on the transducer to orient the robot's frame of reference and using simple thresholding algorithms to segment the 3D images, we tested the accuracy of using the scanner to automatically direct a robot arm that touched two needle tips together within a water tank. RMS measurement error was 3.8% or 1.58 mm for an average path length of 41 mm. Using these same techniques, the autonomous robot also performed simulated needle biopsies of a cyst-like lesion in a tissue phantom. This feasibility study shows the potential for 3D ultrasound guidance of an autonomous surgical robot for simple interventional tasks, including lesion biopsy and foreign body removal.

An Improved Method for Evaluating the Moisture Diffusivity in a Membrane

2010 ◽  
Vol 297-301 ◽  
pp. 682-687 ◽  
Author(s):  
T. Hu ◽  
J.C. Min ◽  
Y.Z. Song
Keyword(s):  
Test Section ◽  
Present Method ◽  
Sandwich Structure ◽  
Simple Structure ◽  
Moisture Diffusivity ◽  
Moisture Resistance ◽  
Airflow Rate ◽  
Water Tank ◽  
Improved Method ◽  
Set Up

A method that combines the experimental measurements and numerical simulations to determine the moisture diffusivity in a membrane has been developed. An experimental set-up was designed and constructed to measure the total moisture resistance. The test section consists of an airflow channel, a membrane, and a water tank, which form a sandwich structure. The process of moisture transport from the water surface to the airstream in the channel is numerically simulated to obtain the variation of the total moisture resistance with the moisture diffusivity in the membrane, which is then determined by comparing the experimental and numerical total moisture resistances. There are three features with the present method, i.e., simple structure of the test section, combination of the experiment and simulation, and consideration of the boundary layer resistances on both sides of the membrane. Tests were conducted on two PVDF membranes with 0.22 and 0.45 μm mean pore diameters. The results show that the moisture diffusivities in both membranes are in the order of 10-6 kgm-1s-1, with a larger pore size tending to yield a larger diffusivity. The moisture diffusivities in both membranes are insensitive to the airflow rate.

Numerical Analysis of the Motion of a Flexible Hose Net Used for Hauling a Box Chamber Net in Set Net Fishery

2012 ◽  
Author(s):  
Daisuke Kitazawa ◽  
Yoichi Mizukami ◽  
Yoshio Hirai
Keyword(s):  
Numerical Analysis ◽  
Drag Force ◽  
Early Morning ◽  
Experimental Result ◽  
Water Tank ◽  
Three Dimension ◽  
Flexible Hose ◽  
Middle Point ◽  
Simple Method ◽  
Time Changes

A set net fishery is one of the most popular fishing methods and has a history of a few hundred years in Japan. The hauling operation of a box chamber net is one of the essential works for fishermen to harvest fishes, not losing and damaging them. However, the current net-hauling system requires many personnel powers with danger works in early morning. The present study proposes a flexible hose net for hauling a box chamber net in an automated way. Flexible hoses are arranged like a brick form and installed in the bottom of the box chamber net. Compressed air is injected into flexible hoses at one edge of the hose net. The water tank models of the set net and the hose net are made based on the similarity law of Tauchi, while the Reynolds dependency is not taken into account. The hose net rose like an S shape to drive fishes into the smaller domain gradually. Then a simple method of numerical analysis is represented to estimate the formation and the tension of the flexible hose net. For simplicity, the formation of a flexible hose net in the direction normal to air injection is uniform. The hose net is assumed to be flexible with and without air inside the hoses. Hence the hose net is approximated by a flexible cable. A maximal tension of the flexible hose net is the key parameter for its design. The tension is expected to be maximal at the middle point on the flexible hose net when the flexible hose net obtains the half of the total buoyancy. Therefore, the formation of the flexible hose net at this time is analyzed in comparison with the experimental result. The projected area, drag coefficient, current velocity, and the tension at the origin (pretension) are varied to investigate the sensitivity of these parameters to the formation of the flexible hose net. When the parameters related to the drag force on the fish cage were varied, little difference could be found among the analyzed results. The drag force on the flexible hose net exerts little effect on its formation, and is overwhelmed by the effects of gravity and buoyancy. The formation of the hose net is sensitive to the tension at the origin. As future studies, the tension will be measured at several points on the hose net in water tank testing by more precise tank model considering the stiffness of the hose and the Reynolds dependency. Then the numerical model will be expanded to three-dimension to take the time changes in the formation of the flexible hoses and drag force into account.

Motion Analysis of Flexible Hose Based on Water Tank Experiment

2018 ◽  
Author(s):  
Xue Zhou ◽  
Yoichi Mizukami ◽  
Takero Yoshida ◽  
Daisuke Kitazawa
Keyword(s):  
Water Pressure ◽  
Air Flow ◽  
Three Dimensional ◽  
Coupled Model ◽  
Maintenance Cost ◽  
Water Tank ◽  
Flexible Hose ◽  
Polyethylene Pipes ◽  
Tank Experiment ◽  
Water Tank Experiment

Set net fishery faces the problems of decrease in harvest, with lack of labor and aging of fishermen. These problems make it necessary to develop a new automatic harvesting way of set net fishery. An automatic net-hauling system is one of the promising ways, while the system using rubber tubes and polyethylene pipes are not prevailing because of the high maintenance cost and the difficulty in the operation. In the present study, the flexible hose net is proposed to harvest fish in the box chamber net of set net fishery. The flexible hose net is installed on the water bottom below the box chamber net. Compressed air is injected from one edge of the hose net to haul the box chamber net gradually, resulting in cornering fish in the other edge. In the preset study, the feasibility of the net-hauling system for set net fishery was examined by water tank experiment. The variation in the formation of the hose net and the time for sinking and floating were examined, changing the parameters such as air pressure and buoyancy balance. As a result, the hose net sank automatically if the weight attached to the hose net was 39% of the total buoyancy of the hose net with full of air. The time spent for sinking operation was about 160 s, which corresponds to about 10 min for actual hose net according to the similarity law. However, it should be noted that the similarity of water pressure could not be reproduced in the water tank experiment. To reduce the sinking time, the initial inner pressure of the hose net must be the atmospheric pressure before the beginning of the sinking operation. There is an inflection point between the flexible hoses with and without air. It is worried that air flow in the flexible hoses may be impeded. So the inside structure of the flexible hoses may have to be improved to secure the air flow in any condition. In relation to the difficulty in reproducing the water pressure condition in the water tank, the numerical analysis will be required to reproduce the motion of the hose net and its sinking time both for scaled and full-scale models. In the future, three-dimensional coupled model of fluid, structure, and air flow will be developed and validated by the experimental data, beginning with the simple two-dimensional modeling of the motion of the hose net.

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