On performance of an oscillating plate underwater propulsion system with variable chordwise flexibility at different depths of submergence

2012 ◽  
Vol 28 ◽  
pp. 152-166 ◽  
Author(s):  
Oleksandr Barannyk ◽  
Bradley J. Buckham ◽  
Peter Oshkai
Keyword(s):  
Propulsion System ◽  
Underwater Propulsion ◽  
Different Depths ◽  
Oscillating Plate

Effect of Chordwise Flexibility and Depth of Submergence on an Oscillating Plate Underwater Propulsion System

2010 ◽  
Author(s):  
Oleksandr Barannyk ◽  
Brad Buckham ◽  
Peter Oshkai
Keyword(s):  
Segment Length ◽  
Driving Frequency ◽  
Force Measurements ◽  
Marine Animals ◽  
Thrust Coefficient ◽  
Underwater Propulsion ◽  
Different Depths ◽  
Primary Focus ◽  
Flexible Segment ◽  
Oscillating Plate

This work was dedicated to the experimental study of oscillating plate propulsors undergoing a combination of heave translation and pitch rotation. The oscillation kinematics are inspired by swimming mechanisms employed by fish and other marine animals. The primary focus was on the propulsive characteristics of such oscillating plates, which were studied by means of direct force measurements in the thrust-producing regime. Experiments were performed at constant Reynolds number and constant heave amplitude. By varying the Strouhal number, the depth of submergence and the chordwise flexibility of the plate, it was possible to investigate corresponding changes in the generated thrust and the hydromechanical efficiency. It was possible to establish a set of parameters, including the driving frequency of the system, the ratio of rigid to flexible segment length of the plate, and the range of Strouhal numbers that led to a peak efficiency of approximately 80%. The experiments involving plates with various ratios of rigid to flexible segment lengths showed that greater flexibility increased the propulsive efficiency and thrust compared to an identical motion of the purely rigid plate. By submerging the plate at different depths, it was observed that the proximity of the propulsor to the bottom of the channel led to overall increase in the thrust coefficient.

Development and testing of an efficient and cost-effective underwater propulsion system

2019 ◽  
Vol 233 (10) ◽  
pp. 1309-1328
Author(s):  
Libero Paolucci ◽  
Emanuele Grasso ◽  
Francesco Grasso ◽  
Niklas König ◽  
Marco Pagliai ◽  
...  
Keyword(s):  
Permanent Magnet ◽  
High Efficiency ◽  
High Reliability ◽  
Underwater Vehicle ◽  
Propulsion System ◽  
Permanent Magnet Synchronous Motors ◽  
Synchronous Motors ◽  
Vehicle Propulsion ◽  
Underwater Propulsion ◽  
Thrust And Torque

Underwater vehicle propulsion performed by exploiting electrical motor is in general the most flexible solution and it is growing in popularity because of its high efficiency both at high and at low advance speed, quick and simple deployment, low costs, and encumbrance. In the present work, permanent magnet synchronous motors for underwater propulsion are proposed. In particular, advanced sensorless control techniques of permanent magnet synchronous motors permit reduced costs, high reliability, and performances. When dealing with small autonomous underwater vehicle propulsion, such devices are hard to find in the market. Hence, the authors focused the research in the development of a system able to perform a reliable rotational speed and torque sensorless estimation. The design and implementation of a complete solution for underwater propulsion are presented as well as a novel rotor polarity identification technique exploiting a high-frequency injection control. Pool tests for the identification of the performances and of the dynamic parameters of the propulsion system are presented. Finally, the possibility of operating a sensorless estimation of the thrust and torque exerted by the propeller and pool test measurements are presented. These features could be exploited to improve navigation accuracy and involves obvious benefits in terms of cost reduction and reliability of the system.

Hydropulse underwater propulsion system

1983 ◽  
Vol 73 (3) ◽  
pp. 1089-1089
Author(s):  
Allen C. Hagelberg ◽  
Clark E. Allardt
Keyword(s):  
Propulsion System ◽  
Underwater Propulsion

An underwater propulsion system with (Bi,Na,Ba) (Ti, Mn)O3 transducer

2021 ◽  
Author(s):  
YUAN QIAN ◽  
Deqing KONG ◽  
Yutaka Doshida ◽  
Manabu AOYAGI ◽  
Minoru Kuribayashi KUROSAWA
Keyword(s):  
Propulsion System ◽  
Underwater Propulsion

scholarly journals Hybrid Rocket Underwater Propulsion: A Preliminary Assessment

Aerospace ◽  
2019 ◽  
Vol 6 (3) ◽  
pp. 28 ◽  
Author(s):  
Heejang Moon ◽  
Seongjoo Han ◽  
Youngjun You ◽  
Minchan Kwon
Keyword(s):  
Nozzle Exit ◽  
Propulsion System ◽  
Test Case ◽  
Test Bed ◽  
Hybrid Rocket ◽  
Preliminary Assessment ◽  
Soft Start ◽  
Rupture Disc ◽  
Underwater Propulsion ◽  
Hybrid Motor

This paper presents an attempt to use the hybrid rocket for marine applications with a 500 N class hybrid motor. A 5-port high density polyethylene (HDPE) fuel grain was used as a test-bed for the preliminary assessment of the underwater boosting device. A rupture disc preset to burst at a given pressure was attached to the nozzle exit to prevent water intrusion where a careful hot-firing sequence was unconditionally required to avoid the wet environment within the chamber. The average thrust level around 450 N was delivered by both a ground test and an underwater test using a water-proof load cell. However, it was found that instantaneous underwater thrusts were prone to vibration, which was due in part to the wake structure downstream of the nozzle exit. Distinctive ignition curves depending on the rupture disc bursting pressure and oxidizer mass flow rate were also investigated. To assess the soft-start capability of the hybrid motor, the minimum power thrust, viewed as the idle test case, was evaluated by modulating the flow controlling valve. It was found that an optimum valve angle, delivering 16.3% of the full throttle test case, sustained the minimum thrust level. This preliminary study suggests that the throttable hybrid propulsion system can be a justifiable candidate for a short-duration, high-speed marine boosting system as an alternative to the solid underwater propulsion system.

scholarly journals Design and evaluation of a fin-based underwater propulsion system

2010 ◽  
Author(s):  
Benjamin Peter ◽  
Roman Ratnaweera ◽  
Wolfgang Fischer ◽  
C Pradalier ◽  
R Y Siegwart
Keyword(s):  
Propulsion System ◽  
Underwater Propulsion
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