Development of a Shipboard Remote Control and Telemetry Experimental System for Large-Scale Model’s Motions and Loads Measurement in Realistic Sea Waves

This chapter describes a mathematical model of tsunami propagation (transient waves). A tsunami is a series of ocean waves triggered by large-scale disturbances of the ocean, including earthquakes, as well as landslides, volcanic eruptions, and meteorites. Tsunamis have very long wavelengths (typically hundreds of kilometers). They have also been called “tidal waves” or “seismic sea waves,” but both terms are misleading. The chapter first considers the boundary-value problem before modeling two special cases of tsunami generation, one due to an initial displacement on the free surface and the other due to tilting of the seafloor. It also discusses surface waves on deep water and how fast the wave energy propagates and concludes with an analysis of leading waves due to a transient disturbance.

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Experimental Investigation of Wave-Induced Ship Hydroelastic Vibrations by Large-Scale Model Measurement in Coastal Waves

Shock and Vibration ◽

10.1155/2016/9296783 ◽

2016 ◽

Vol 2016 ◽

pp. 1-14 ◽

Cited By ~ 3

Author(s):

Jialong Jiao ◽

Huilong Ren ◽

Shuzheng Sun ◽

Christiaan Adika Adenya

Keyword(s):

Large Scale ◽

Testing Procedure ◽

Scale Model ◽

Sea Waves ◽

Load Pressure ◽

Large Scale Model ◽

Wide Range ◽

Hydroelastic Vibrations ◽

Wave Induced ◽

Model Measurement

Ship hydroelastic vibration is an issue involving mutual interactions among inertial, hydrodynamic, and elastic forces. The conventional laboratory tests for wave-induced hydroelastic vibrations of ships are performed in tank conditions. An alternative approach to the conventional laboratory basin measurement, proposed in this paper, is to perform tests by large-scale model measurement in real sea waves. In order to perform this kind of novel experimental measurement, a large-scale free running model and the experiment scheme are proposed and introduced. The proposed testing methodology is quite general and applicable to a wide range of ship hydrodynamic experimental research. The testing procedure is presented by illustrating a 5-hour voyage trial of the large-scale model carried out at Huludao harbor of China in August 2015. Hammer tests were performed to identify the natural frequencies of the ship model at the beginning of the tests. Then a series of tests under different sailing conditions were carried out to investigate the vibrational characteristics of the model. As a postvoyage analysis, load, pressure, acceleration, and motion responses of the model are studied with respect to different time durations based on the measured data.

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The Track and Accompanying Sea Wave Forecasts of the Supertyphoon Mangkhut (2018) by a Real-Time Regional Forecast System

Journal of Atmospheric and Oceanic Technology ◽

10.1175/jtech-d-19-0196.1 ◽

2020 ◽

Vol 37 (11) ◽

pp. 2075-2084

Author(s):

Yuhang Zhu ◽

Yineng Li ◽

Shiqiu Peng

Keyword(s):

Real Time ◽

Large Scale ◽

Negative Impact ◽

Wave Model ◽

Forecast Skill ◽

Track Forecast ◽

Sea Waves ◽

Mean Error ◽

Forecasting System ◽

Sea Wave

AbstractThe track and accompanying sea wave forecasts of Typhoon Mangkhut (2018) by a real-time regional forecasting system are assessed in this study. The real-time regional forecasting system shows a good track forecast skill with a mean error of 69.9 km for the forecast period of 1–72 h. In particular, it predicted well the landfall location on the coastal island of South China with distance (time) biases of 76.89 km (3 h) averaging over all forecasting made during 1–72 h and only 3.55 km (1 h) for the forecasting initialized 27 h ahead of the landfall. The sea waves induced by Mangkhut (2018) were also predicted well by the wave model of the forecasting system with a mean error of 0.54 m and a mean correlation coefficient up to 0.94 for significant wave height. Results from sensitivity experiments show that the improvement of track forecasting skill for Mangkhut (2018) are mainly attributed to application of a scale-selective data assimilation scheme in the atmosphere model that helps to maintain a more realistic large-scale flow obtained from the GFS forecasts, whereas the air–sea coupling has slightly negative impact on the track forecast skill.

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Design of New Excavator with Telescopic Arm

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.228-229.340 ◽

2011 ◽

Vol 228-229 ◽

pp. 340-344

Author(s):

Chuan Can Chen ◽

Xi Dong Chen

Keyword(s):

Remote Control ◽

Working Conditions ◽

High Speed ◽

Large Scale ◽

Control Technology ◽

Foundation Pit ◽

Obstacle Avoiding

In order to make better use of excavator in foundation pit, a new excavator with telescopic arm is designed in this paper. The innovations mainly manifests in four aspects. First, the use of telescopic arm decreases the height for the excavation in foundation pit. Secondly, the design of truss-guide and trolley brings a high speed to excavator’s lateral move in large scale, easy for dirt shoveling in the wide foundation pit. Thirdly, the travelling system with two pails of dual-pedrail makes it possible for excavator free walking, flexible steering, and obstacle avoiding. The last but not the least, the wireless remote control technology can keep operators distant from danger and other unpleasant working conditions.

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Direct numerical simulation of the oscillatory flow around a sphere resting on a rough bottom

Journal of Fluid Mechanics ◽

10.1017/jfm.2017.242 ◽

2017 ◽

Vol 822 ◽

pp. 235-266 ◽

Cited By ~ 3

Author(s):

Marco Mazzuoli ◽

Paolo Blondeaux ◽

Julian Simeonov ◽

Joseph Calantoni

Keyword(s):

Reynolds Number ◽

Large Scale ◽

Oscillatory Flow ◽

Stokes Equations ◽

Coarse Sand ◽

Spherical Particles ◽

Navier Stokes ◽

Sea Waves ◽

Spherical Object ◽

Navier Stokes Equations

The oscillatory flow around a spherical object lying on a rough bottom is investigated by means of direct numerical simulations of the continuity and Navier–Stokes equations. The rough bottom is simulated by a layer/multiple layers of spherical particles, the size of which is much smaller that the size of the object. The period and amplitude of the velocity oscillations of the free stream are chosen to mimic the flow at the bottom of sea waves and the size of the small spherical particles falls in the range of coarse sand/very fine gravel. Even though the computational costs allow only the simulation of moderate values of the Reynolds number characterizing the bottom boundary layer, the results show that the coherent vortex structures, shed by the spherical object, can break up and generate turbulence, if the Reynolds number of the object is sufficiently large. The knowledge of the velocity field allows the dynamics of the large-scale coherent vortices shed by the object to be determined and turbulence characteristics to be evaluated. Moreover, the forces and torques acting on both the large spherical object and the small particles, simulating sediment grains, can be determined and analysed, thus laying the groundwork for the investigation of sediment dynamics and scour developments.

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Simulation on the Dynamic Behavior of the Propulsion System Subjected by Hull Deformation for Large Vessels

Volume 3: Structures, Safety and Reliability ◽

10.1115/omae2015-42391 ◽

2015 ◽

Author(s):

Zhe Tian ◽

Xinping Yan ◽

Cong Zhang ◽

Weizhong Tan

Keyword(s):

Dynamic Behavior ◽

Large Scale ◽

Propulsion System ◽

Normal Operation ◽

Sea Waves ◽

Ship Propulsion ◽

Coupling System ◽

Large Ship ◽

Important Position ◽

Large Vessels

This paper aims to investigate the dynamic behavior of the large ship propulsion system subjected by hull deformation. Evident tendency of development of large scale ships was shown that the interaction between the propulsion shaft and ship hull becomes much severer than before. The excited forces caused by severe sea waves have considerable effects on the hull deformation which could have further impact on the shaft propulsion system. On the contrary, the operation quality of ships and the durability of machines are threatened by the malfunctions of shaft propulsion system. As a result the reliability of the vessels has been put in an important position by the companies and the governments all over the world. For scientists, investigating the dynamic behavior of the propulsion system subjected by the hull deformation is a meaningful research to avoid malfunction of machine in navigation. Numerical analysis is now an effective method to analyze some key components on large vessels. Taking the 8530TEU container as an example, a numerical model of the large ship propulsion-hull coupling system is presented in this paper to analyze the dynamic behavior of the ship propulsion system subjected by hull deformation. The hull deformations are obtained under different sea conditions as the exciting forces which are used on the coupling system. Then the dynamical responds of the ship shaft are obtained. Based on the results, suggestions are proposed to ensure the normal operation of the propulsion system in different sea conditions.

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DEVELOPMENT OF PHYSICAL MODEL VEHICLE WITH REMOTIONAL CONTROL FOR EXPERIMENTAL STUDIES OF VEHICLE PROPERTIES

The National Transport University Bulletin ◽

10.33744/2308-6645-2020-1-46-341-352 ◽

2020 ◽

Vol 1 (46) ◽

pp. 341-352

Author(s):

Timkov O ◽

◽

Yashchenko D ◽

Keyword(s):

Mathematical Model ◽

Experimental Study ◽

Remote Control ◽

Physical Model ◽

Large Scale ◽

Experimental Studies ◽

Scale Model ◽

Recording Equipment ◽

Control Equipment ◽

The Future

The article is devoted to the development of the physical model of the vehicle, the equipment of the measuring, recording and remote control equipment for the experimental study of the properties vehicles. The construction of the physical model and the used electronic modules is described in detail, references are given to the application libraries and the code of the first part of the program for remote control. In the future, it is planned to develop a mathematical model of the movement of a passenger vehicle and to check its adequacy in conducting experimental studies on maneuverability on a physical model. The aim of the article is developed the physical model of the vehicle, equipped with measuring, recording and remote control equipment, for the experimental study of the properties of vehicle. Materials and research methods: development and designing (experimental research of properties of vehicles on the physical model); remote control; wheeled controlled module. The self-propelled large-scale model of the vehicle, reproducing a passenger car of the category M1, with a controlled wheelbase and a rear drive axle, has been developed. The model is equipped with the necessary measuring and recording equipment and remote control equipment. The software of the model allows you to implement both control manual and the given algorithm. In the future, it is planned to develop a mathematical model of the vehicle motion and to check its adequacy on the developed physical model. The obtained results will allow to improve not only the mathematical model, but also the experimental physical model and proceed further to the study of the properties of hybrid road trains with an active trailer link. KEY WORDS: VEHICLE, PHYSICAL MODEL, EXPERIMENT, STUDY, MODULE, MEMORY CARD, ACCELEROMETER, PROGRAM.

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Transformation of Water Wave Spectra into Time Series of Surface Elevation

Earth ◽

10.3390/earth2040059 ◽

2021 ◽

Vol 2 (4) ◽

pp. 997-1005

Author(s):

Phelype Haron Oleinik ◽

Gabriel Pereira Tavares ◽

Bianca Neves Machado ◽

Liércio André Isoldi

Keyword(s):

Time Series ◽

Time Domain ◽

Water Surface ◽

Large Scale ◽

Wave Spectrum ◽

Ocean Waves ◽

Surface Elevation ◽

Sea Waves ◽

Water Surface Elevation ◽

Input Spectrum

Spectral wave modelling is widely used to simulate large-scale wind–wave processes due to its low computation cost and relatively simpler formulation, in comparison to phase-resolving or hydrodynamic models. However, some applications require a time-domain representation of sea waves. This article proposes a methodology to transform the wave spectrum into a time series of water surface elevation for applications that require a time-domain representation of ocean waves. The proposed method uses a generated phase spectrum and the inverse Fourier transform to turn the wave spectrum into a time series of water surface elevation. The consistency of the methodology is then verified. The results show that it is capable of correctly transforming the wave spectrum, and the significant wave height of the resulting time series is within 5% of that of the input spectrum.

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A simple hydraulic drive for remote control of the Huxley-style micromanipulator

AJP Cell Physiology ◽

10.1152/ajpcell.1988.254.4.c577 ◽

1988 ◽

Vol 254 (4) ◽

pp. C577-C581 ◽

Cited By ~ 1

Author(s):

J. W. Krueger

Keyword(s):

Remote Control ◽

Hydraulic Drive ◽

Experimental System ◽

Electrical Noise ◽

Potential Sources ◽

Electrodeposited Metal ◽

Metal Bellows

Electrodeposited metal bellows permit the construction of simple, reliable, and inexpensive hydraulic drives for the Huxley-style micromanipulator. This approach enables precise remote control of micromanipulation without introducing conductive leads or other potential sources of electrical noise near the experimental system. Moreover, the bellows arrangement preserves a stability and reproducibility in the positioning of the heavier transducers that is not matched by other hydraulic micromanipulators. The small size of the hydraulic coupler enables easy installation, and it can be adapted to preexisting manipulators. Importantly, the manipulator's original micrometer control is preserved, a feature that allows the investigator to tailor the apparatus for novel arrangements for micromanipulation.

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