An Auxiliary Thruster for Free-Running Model Ship Test

2013 ◽  
Author(s):  
Yoshiaki Tsukada ◽  
Michio Ueno ◽  
Hideki Miyazaki ◽  
Tadanori Takimoto
Keyword(s):  
Theoretical Calculations ◽  
Full Scale ◽  
Load Cell ◽  
Friction Resistance ◽  
Target Values ◽  
Trial Test ◽  
Free Running ◽  
Ship Performance ◽  
Force Data ◽  
Ship Propeller

The free-running model ship test is an important measure to investigate into ship performance and response in various situations. Its basis is the Froude’s similarity law. Since Reynolds number remains quite different between model ships and full-scale ones, phenomena concerning viscosity cannot be similar. One of the most specific features related to the viscosity is the friction resistance and thus propeller load that differs to a large extent between model ships and full-scale ones. This difference affects torque and thrust responses in waves and wind, and also rudder effectiveness or manoeuvrability. The authors have developed a prototype of auxiliary thruster that assists free-running model ships’ propeller. The auxiliary thruster can control its forward force and adjusts the model ship propeller load to arbitrarily time varying target values. The prototype consists of a duct fan, a load cell mounting the duct fan on it, an amplifier for the duct fan, and a PC. The PC controls the auxiliary thrust, or forward force generated by the duct fan, using the model ship speed and the force data measured by the load cell. This report presents the prototype of auxiliary thruster and its trial test applied to a free-running model ship to study the effect of propeller load on manoeuvrability. The trial test clarified how the auxiliary thrust or the propeller load affects the model ship responses to steering. Theoretical calculations simulating the effect of propeller load corresponding to the trial test confirmed these effects. Applicability of the auxiliary thruster to other free-running model tests is also discussed.

Estimation of Fluctuating Propeller Torque of Full-Scale Ship Using Free-Running Model in Waves

2015 ◽  
Author(s):  
Michio Ueno ◽  
Yoshiaki Tsukada
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Full Scale ◽  
Engine Torque ◽  
Engine Model ◽  
Frequency Components ◽  
Free Running ◽  
External Forces ◽  
Ship Propeller ◽  
Ship Speed

The authors propose a method to estimate full-scale propeller torque consisting of low-frequency and high-frequency components in waves using measured data of free-running model ship. The duct fan auxiliary thruster (DFAT) [1] and the rudder-effectiveness and speed correction (RSC) [2,3] ensure similar model ship motion to full-scale in external forces, where RSC controls the model ship propeller rate of revolution and the auxiliary thrust depending on measured model ship speed. Analyzing a fluctuating component of effective inflow velocity to propeller due to waves, the method estimates full-scale fluctuating propeller torque in waves. This method also makes it possible to adopt into free-running model ship tests any engine model simulating interaction between propeller torque and engine torque. Trial application of the method exemplifies the property of full-scale fluctuating propeller torque comparing with that of model ship.

scholarly journals Investigating the Performance of a Ship by Matching the Stern Hull Form to Propeller and Engine Power

2021 ◽  
Vol 3 (2) ◽  
pp. 154-159
Author(s):  
Andi Dian Eka Anggriani ◽  
Suandar Baso
Keyword(s):  
High Speed ◽  
Tip Clearance ◽  
Design Stage ◽  
Hull Form ◽  
Preliminary Ship Design ◽  
Free Running ◽  
Ship Performance ◽  
Ship Propeller ◽  
Ship Speed ◽  
Engine Power

Designing the form of the ship stern hull could have some impacts on the efficiency of ship propeller and the requirement of the ship speed. Therefore, stern hull form of a ship matched to its propeller and engine power is important consideration in preliminary ship design stage. The main objective of this study is to investigate ship performance by matching the stern hull shape to the propeller diameter and engine power toward high speed. This study was conducted by free running model test and Maxsurf Resistance application. The stern forms were employed U-shape and V-shape. In addition, the fixed pitch propeller (FPP) with three blades was used and the diameter is varied into three sizes 0.032 m, 0.040 m, and 0.048 m. The results show the increase of propeller diameter increases model’s speed for both U-shape and V-shape stern and the effect of the propeller diameter on the speed could be described by using the equations of second-order polynomial. The optimum propeller diameter could be determined taking into account stern hull form, stern shape, tip clearance, and proper speed where then propeller diameter related to draft is given by 0.79T with tip clearance 10%Dp for both U-shape and V-shape. The ship resistances of U-shape stern at Fr 0.221 and V-shape at 0.208 are obtained approximately 89.797 KN and 77.10 KN respectively. Furthermore, the powers of ship for both U-shape and V-shape at those Fr are obtained 904,374 KW and 726,807 KW respectively. Finally, the best stern hull form matched to propeller diameter and engine power is selected and given by U-shape stern.

Full-scale ship propeller torque in wind and waves estimated by free-running model test

2019 ◽  
Vol 184 ◽  
pp. 332-343 ◽  
Author(s):  
Michio Ueno ◽  
Ryosuke Suzuki ◽  
Yoshiaki Tsukada
Keyword(s):  
Model Test ◽  
Full Scale ◽  
Free Running ◽  
Ship Propeller

scholarly journals Design and Realization of a Miniature Capacitive Silicon Force Sensor for Loads up to 500 KG

2000 ◽  
Author(s):  
R. A. F. Zwijze ◽  
R. J. Wiegerink ◽  
G. J. M. Krijnen ◽  
T. Hien ◽  
M. C. Elwenspoek
Keyword(s):  
Force Sensor ◽  
Full Scale ◽  
Load Cell ◽  
Measurement Results ◽  
Previous Design ◽  
Cell Force

Abstract In this paper, a micromachined silicon load cell (force sensor) is presented for measuring loads up to 500 kg. The load cell has been realized and tested. Measurement results show a hysteresis error of ±0.02% of the full-scale output (fso). Creep at 500 kg after 30 minutes is within 0.01% of the fso. These measurements show that the performance has improved by a factor of 10 compared to the previous design.

Evaluation of a Small and Fast Planing Boat’s Seakeeping Performance at the Design Stage

2015 ◽  
Author(s):  
Dong Jin Kim ◽  
Sun Young Kim
Keyword(s):  
Model Tests ◽  
Full Scale ◽  
Scale Model ◽  
Design Stage ◽  
Small Scale ◽  
Irregular Wave ◽  
Seakeeping Performance ◽  
Head Waves ◽  
Scale Ratio ◽  
Free Running

Seakeeping performance of a planing boat should be sufficiently considered and evaluated at the design stage for its safe running in rough seas. Model tests in seakeeping model basins are often performed to predict the performance of full-scale planing boats. But, there are many limitations of tank size and wave maker capacity, in particular, for fast small planing boats due to small scale ratio and high Froude numbers of their scale models. In this research, scale model tests are tried in various test conditions, and results are summarized and analyzed to predict a 3 ton-class fast small planing boats designed. In a long and narrow tank, towing tests for a bare hull model are performed with regular head waves and long crested irregular head waves. Motion RAOs are derived from irregular wave tests, and they are in good agreements with RAOs in regular waves. Next, model ships with one water-jet propulsion system are built, and free running model tests are performed in ocean basins. Wave conditions such as significant heights, modal periods, and directions are varied for the free running tests. Motion RMS values, and RAOs are obtained through statistical approaches. They are compared with the results in captive tests for the bare hull model, and are used to predict the full-scale boat performances.

A new moving model test method for the measurement of aerodynamic drag coefficient of high-speed trains based on machine vision

2017 ◽  
Vol 232 (5) ◽  
pp. 1425-1436 ◽  
Author(s):  
Zhiwei Li ◽  
Mingzhi Yang ◽  
Sha Huang ◽  
Dan Zhou
Keyword(s):  
Machine Vision ◽  
Drag Coefficient ◽  
Model Test ◽  
High Speed ◽  
Aerodynamic Drag ◽  
Full Scale ◽  
Test Method ◽  
Test Accuracy ◽  
Friction Resistance ◽  
Aerodynamic Drag Coefficient

A moving model test method has been proposed to measure the aerodynamic drag coefficient of a high-speed train based on machine vision technology. The total resistance can be expressed as the track friction resistance and the aerodynamic drag according to Davis equation. Cameras are set on one side of the track to capture the pictures of the train, from which the line marks on the side surface of the train are extracted and analyzed to calculate the speed and acceleration of the train. According to Newton’s second law, the aerodynamic drag coefficient can be resolved through multiple tests at different train speeds. Comparisons are carried out with the full-scale coasting test, wind tunnel test, and numerical simulation; good agreement is obtained between the moving model test and the full-scale field coasting test with difference within 1.51%, which verifies that the method proposed in this paper is feasible and reliable. This method can accurately simulate the relative movement between the train, air, and ground. The non-contact measurement characteristic will increase the test accuracy, providing a new experimental method for the aerodynamic measurement.

Industrial Scale HL-LL Waste Canister Transfer Demonstrator

2011 ◽  
Author(s):  
Pascal Champ ◽  
Jacques Bardet ◽  
Benjamin Attias
Keyword(s):  
Full Scale ◽  
Industrial Scale ◽  
Transfer System ◽  
Actual System ◽  
Geological Disposal ◽  
Engineering Studies ◽  
Deep Geological Disposal ◽  
Trial Test

In 2007, Cegelec has been attributed a contract by ANDRA under the ESDRED program (Engineering Studies and Demonstrations of Repository Designs) financed by 13 organisations across Europe, for the design, manufacturing and trial test of a full scale industrial demonstrator of HL-LL waste canister transfer system. Completed in 2009, this project gives a good synthesis of solutions the industry can offer in order to manage HLW transportation with regard to deep geological disposal. This paper highlights solutions developed and results achieved with numerous pictures of the actual system.

Development of a Force Sensing Instrument Assisted Soft Tissue Mobilization Device

2016 ◽  
Author(s):  
Ahmed M. Alotaibi ◽  
Sohel Anwar ◽  
M. Terry Loghmani ◽  
Stanley Chien
Keyword(s):  
Soft Tissue ◽  
Load Cell ◽  
Force Measurements ◽  
Clinical Practices ◽  
Stroke Frequency ◽  
Graston Technique ◽  
Overall Design ◽  
Force Components ◽  
Soft Tissue Mobilization ◽  
Force Data

Instrument assisted soft tissue mobilization (IASTM) is a form of massage using rigid manufactured or cast devices. The delivered force, which is a critical parameter in massage during IASTM, has not been measured or standardized for most clinical practices. In addition to the force, the angle of treatment and frequency play an important role during IASTM. As a result, there is a strong need to characterize the delivered force to a patient, angle of treatment, and stroke frequency. This paper proposes a novel mechatronic design for a specific instrument from Graston Technique® (Model GT-3), which is a frequently used tool to clinically deliver localize pressure to the soft tissue. The design uses a 3D load cell, which can measure all three force components force simultaneously. The overall design is implemented with an IMUduino microcontroller chip which can also measure tool orientation angles and provide computed stroke frequency. The prototype of the mechatronic IASTM tool was validated for force measurements using an electronic plate scale that provided the baseline force values to compare with the applied force magnitudes measured by the device. The load cell measurements and the scale readings were found to be in agreement within the expected degree of accuracy. The stroke frequency was computed using the force data and determining the peaks during force application. The orientation angles were obtained from the built-in sensors in the microchip.

Force, Reaction Time, and Precision of Kung Fu Strikes

2009 ◽  
Vol 109 (1) ◽  
pp. 295-303 ◽  
Author(s):  
Osmar Pinto Neto ◽  
Marcos Tadeu Tavares Pacheco ◽  
Richard Bolander ◽  
Cynthia Bir
Keyword(s):  
Reaction Time ◽  
Body Mass ◽  
Pressure Sensor ◽  
Martial Arts ◽  
High Speed ◽  
Load Cell ◽  
Men And Women ◽  
Kung Fu ◽  
Force Reaction ◽  
Force Data

The goal was to compare values of force, precision, and reaction time of several martial arts punches and palm strikes performed by advanced and intermediate Kung Fu practitioners, both men and women. 13 Kung Fu practitioners, 10 men and three women, participated. Only the men, three advanced and seven intermediate, were considered for comparisons between levels. Reaction time values were obtained using two high speed cameras that recorded each strike at 2500 Hz. Force of impact was measured by a load cell. For comparisons of groups, force data were normalized by participant's body mass and height. Precision of the strikes was determined by a high speed pressure sensor. The results show that palm strikes were stronger than punches. Women in the study presented, on average, lower values of reaction time and force but higher values of precision than men. Advanced participants presented higher forces than intermediate participants. Significant negative correlations between the values of force and precision and the values of force and reaction time were also found.

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