Thi Thanh Diep Nguyen | Changwon National University (original) (raw)
Uploads
Papers by Thi Thanh Diep Nguyen
Science Progress
A moored floating platform has great potential in ocean engineering applications because the moor... more A moored floating platform has great potential in ocean engineering applications because the mooring system is necessary to keep a floating platform in the station. It relates directly to operational efficiency and safety of a floating platform. This study presents a comprehensive assessment of the dynamics of a moored semi-submersible in waves by performing model test and numerical simulation. First, a three-dimensional panel method was used to estimate the motion of a moored semi-submersible in waves. A semi-submersible is modelled as a rigid body with six degrees-of-freedom (6DOF) motion. Dynamic response analysis of a semi-submersible is performed in regular wave and irregular wave. Second, the model test is performed in various wave directions. An Optical-based system is used to measure 6DOF motion of a semi-submersible. Numerical results are compared with the experimental results in various wave directions. Wavelength and wave direction showed significant effects on the motion...
Journal of Ocean Engineering and Technology
Moored floating platforms have great potential in ocean engineering applications because a moorin... more Moored floating platforms have great potential in ocean engineering applications because a mooring system is necessary to keep the platform in station, which is directly related to the operational efficiency and safety of the platform. This paper briefly introduces the technical and operational details of an optical sensor for measuring the tension of mooring lines of a moored platform in waves. In order to check the performance of optical sensors, an experiment with a moored floating platform in waves is carried out in the wave tank at Changwon National University. The experiment is performed in regular waves and irregular waves with a semi-submersible and triangle platform. The performance of the optical sensor is confirmed by comparing the results of the tension of the mooring lines by the optical sensor and tension gauges. The maximum tension of the mooring lines is estimated to investigate the mooring dynamics due to the effect of the wave direction and wavelength in the regula...
In the past, various research on the effects of waves generated by ships has been investigated. T... more In the past, various research on the effects of waves generated by ships has been investigated. The most noticeable effect of the waves generated by a passing ship is the increase of the hydrodynamic forces and the unwanted large motion of the moored ship and high mooring forces that occur. Thus, it is crucial to investigate the effect of the waves generated by the passing ship near port on the motion of the moored ship and the tension of the mooring lines. A model test was performed with virtual ship-generated waves in a square tank at CWNU (Changwon National University). The IMU (Inertial Measurement Unit) and Optical-based system were used to measure the 6DOF (Six Degrees of Freedom) motion of the moored floater. Additionally the tension of mooring lines were measured by the tension gauges. The effects of the wave direction and wave height generated by the virtual ship-generated waves on the motion of the moored floater were analyzed.
Journal of Ocean Engineering and Technology, 2021
The maneuvering performance of a ship on the actual sea is very different from that in calm water... more The maneuvering performance of a ship on the actual sea is very different from that in calm water due to wave-induced motion. Enhancement of a ship’s maneuverability in waves at the design stage is an important way to ensure that the ship navigates safely. This paper focuses on the maneuvering prediction of a Russian trawler in wind and irregular waves. First, a unified seakeeping and maneuvering analysis of a Russian trawler is proposed. The hydrodynamic forces acting on the hull in calm water were estimated using empirical formulas based on a database containing information on several fishing vessels. A simulation of the standard maneuvering of the Russian trawler was conducted in calm water, which was checked using the International Maritime Organization (IMO) standards for ship maneuvering. Second, a unified model of seakeeping and maneuvering that considers the effect of wind and waves is proposed. The wave forces were estimated by a three-dimensional (3D) panel program (ANSYS-...
Journal of Marine Science and Technology, 2020
The sloshing of liquid in a partially filled tank is of great concern to aerospace vehicles, road... more The sloshing of liquid in a partially filled tank is of great concern to aerospace vehicles, road vehicles and ships due to complex nonlinear motion involving the free surface of the liquid. Sloshing is a type of violent liquid motion that is created by forces such as an impact and breaking waves. Oscillation of the liquid in the vessel may threaten navigation safety. This paper attempts to predict the hydrodynamic forces induced by the motion of liquid inside a tank based on experiment and Recurrent Neural Network (RNN). The experiment of sloshing test is carried out using the Stewart platform at Changwon National University (CWNU). The motions of the LNG carrier are inputted into the Stewart platform, then the hydrodynamic forces induced by the liquid in the tank are analyzed. Then, an RNN is used to model the complex dynamics of the sloshing load in the liquid tank and the RNN predictions are compared with the experimental results. This new approach, which offers robust modeling ...
Journal of Marine Science and Technology, 2020
The sloshing of liquid in a partially filled tank is of great concern to aerospace vehicles, road... more The sloshing of liquid in a partially filled tank is of great concern to aerospace vehicles, road vehicles and ships due to complex nonlinear motion involving the free surface of the liquid. Sloshing is a type of violent liquid motion that is created by forces such as an impact and breaking waves. Oscillation of the liquid in the vessel may threaten navigation safety. This paper attempts to predict the hydrodynamic forces induced by the motion of liquid inside a tank based on experiment and Recurrent Neural Network (RNN). The experiment of sloshing test is carried out using the Stewart platform at Changwon National University (CWNU). The motions of the LNG carrier are inputted into the Stewart platform, then the hydrodynamic forces induced by the liquid in the tank are analyzed. Then, an RNN is used to model the complex dynamics of the sloshing load in the liquid tank and the RNN predictions are compared with the experimental results. This new approach, which offers robust modeling of the complex dynamics of a sloshing load in an LNG carrier, can be applied to simulate the ship maneuvering in waves.
Brodogradnja, 2017
To assess the manoeuvrability of ships in shallow water at the early design stage, reliable simul... more To assess the manoeuvrability of ships in shallow water at the early design stage, reliable simulation models which present shallow water effect are required. However, studies on the manoeuvrability of ship at low speeds in shallow water have been performed less than manoeuvrability in deep water. Also, the limitation of model that the effects of the keel clearance on manoeuvrability are applied to has been validated through previous studies. In this study, the manoeuvrability characteristics of the ship sailing in shallow water at low speed are evaluated by applying the mathematical model considering the shallow water effect. And the sensitivity analysis on shallow water manoeuvring simulation is performed in order to determine hydrodynamic derivatives which are necessary to be derived exactly due to the limitation of the shallow water model used in previous studies. Through this study, it could be confirmed that great importance of estimation of manoeuvrability could be found through the sensitivity index factor of hydrodynamic derivatives changing in the situation operating the shallow water at low speed.
J. Navig. Port Re, 2020
In recent years, there have been concerted efforts toward predicting ship maneuvering in shallow ... more In recent years, there have been concerted efforts toward predicting ship maneuvering in shallow water since the majority of ship' s accidents near harbors commonly occur in shallow and restricted waters. Enhancement of ship maneuverability at the design stage is crucial in ensuring that a ship navigates safely. However, though challenging, establishing the mathematical model of ship maneuvering motion is recognized as crucial toward accurately predicting the assessment of maneuverability. This paper focused on a study on sensitivity analysis of the hydrodynamic coefficients on the maneuverability prediction of KVLCC2 in shallow waters. Hydrodynamic coefficients at different water depths were estimated from the experimental results conducted in the square tank at Changwon National University (CWNU). The simulation of standard maneuvering of KVLLC2 in shallow waters was compared with the results of the Free Running Model Test (FRMT) in shallow waters from other institutes. Additionally the sensitivity analysis of all hydrodynamic coefficients was conducted by deviating each hydrodynamic derivative from the experimental results. The standard maneuvering parameters including turning tests and zigzag maneuvers were conducted at different water depths and their effects on the standard maneuvering parameters were assessed to understand the importance of different derivatives in ship maneuvering in shallow waters.
Science Progress
A moored floating platform has great potential in ocean engineering applications because the moor... more A moored floating platform has great potential in ocean engineering applications because the mooring system is necessary to keep a floating platform in the station. It relates directly to operational efficiency and safety of a floating platform. This study presents a comprehensive assessment of the dynamics of a moored semi-submersible in waves by performing model test and numerical simulation. First, a three-dimensional panel method was used to estimate the motion of a moored semi-submersible in waves. A semi-submersible is modelled as a rigid body with six degrees-of-freedom (6DOF) motion. Dynamic response analysis of a semi-submersible is performed in regular wave and irregular wave. Second, the model test is performed in various wave directions. An Optical-based system is used to measure 6DOF motion of a semi-submersible. Numerical results are compared with the experimental results in various wave directions. Wavelength and wave direction showed significant effects on the motion...
Journal of Ocean Engineering and Technology
Moored floating platforms have great potential in ocean engineering applications because a moorin... more Moored floating platforms have great potential in ocean engineering applications because a mooring system is necessary to keep the platform in station, which is directly related to the operational efficiency and safety of the platform. This paper briefly introduces the technical and operational details of an optical sensor for measuring the tension of mooring lines of a moored platform in waves. In order to check the performance of optical sensors, an experiment with a moored floating platform in waves is carried out in the wave tank at Changwon National University. The experiment is performed in regular waves and irregular waves with a semi-submersible and triangle platform. The performance of the optical sensor is confirmed by comparing the results of the tension of the mooring lines by the optical sensor and tension gauges. The maximum tension of the mooring lines is estimated to investigate the mooring dynamics due to the effect of the wave direction and wavelength in the regula...
In the past, various research on the effects of waves generated by ships has been investigated. T... more In the past, various research on the effects of waves generated by ships has been investigated. The most noticeable effect of the waves generated by a passing ship is the increase of the hydrodynamic forces and the unwanted large motion of the moored ship and high mooring forces that occur. Thus, it is crucial to investigate the effect of the waves generated by the passing ship near port on the motion of the moored ship and the tension of the mooring lines. A model test was performed with virtual ship-generated waves in a square tank at CWNU (Changwon National University). The IMU (Inertial Measurement Unit) and Optical-based system were used to measure the 6DOF (Six Degrees of Freedom) motion of the moored floater. Additionally the tension of mooring lines were measured by the tension gauges. The effects of the wave direction and wave height generated by the virtual ship-generated waves on the motion of the moored floater were analyzed.
Journal of Ocean Engineering and Technology, 2021
The maneuvering performance of a ship on the actual sea is very different from that in calm water... more The maneuvering performance of a ship on the actual sea is very different from that in calm water due to wave-induced motion. Enhancement of a ship’s maneuverability in waves at the design stage is an important way to ensure that the ship navigates safely. This paper focuses on the maneuvering prediction of a Russian trawler in wind and irregular waves. First, a unified seakeeping and maneuvering analysis of a Russian trawler is proposed. The hydrodynamic forces acting on the hull in calm water were estimated using empirical formulas based on a database containing information on several fishing vessels. A simulation of the standard maneuvering of the Russian trawler was conducted in calm water, which was checked using the International Maritime Organization (IMO) standards for ship maneuvering. Second, a unified model of seakeeping and maneuvering that considers the effect of wind and waves is proposed. The wave forces were estimated by a three-dimensional (3D) panel program (ANSYS-...
Journal of Marine Science and Technology, 2020
The sloshing of liquid in a partially filled tank is of great concern to aerospace vehicles, road... more The sloshing of liquid in a partially filled tank is of great concern to aerospace vehicles, road vehicles and ships due to complex nonlinear motion involving the free surface of the liquid. Sloshing is a type of violent liquid motion that is created by forces such as an impact and breaking waves. Oscillation of the liquid in the vessel may threaten navigation safety. This paper attempts to predict the hydrodynamic forces induced by the motion of liquid inside a tank based on experiment and Recurrent Neural Network (RNN). The experiment of sloshing test is carried out using the Stewart platform at Changwon National University (CWNU). The motions of the LNG carrier are inputted into the Stewart platform, then the hydrodynamic forces induced by the liquid in the tank are analyzed. Then, an RNN is used to model the complex dynamics of the sloshing load in the liquid tank and the RNN predictions are compared with the experimental results. This new approach, which offers robust modeling ...
Journal of Marine Science and Technology, 2020
The sloshing of liquid in a partially filled tank is of great concern to aerospace vehicles, road... more The sloshing of liquid in a partially filled tank is of great concern to aerospace vehicles, road vehicles and ships due to complex nonlinear motion involving the free surface of the liquid. Sloshing is a type of violent liquid motion that is created by forces such as an impact and breaking waves. Oscillation of the liquid in the vessel may threaten navigation safety. This paper attempts to predict the hydrodynamic forces induced by the motion of liquid inside a tank based on experiment and Recurrent Neural Network (RNN). The experiment of sloshing test is carried out using the Stewart platform at Changwon National University (CWNU). The motions of the LNG carrier are inputted into the Stewart platform, then the hydrodynamic forces induced by the liquid in the tank are analyzed. Then, an RNN is used to model the complex dynamics of the sloshing load in the liquid tank and the RNN predictions are compared with the experimental results. This new approach, which offers robust modeling of the complex dynamics of a sloshing load in an LNG carrier, can be applied to simulate the ship maneuvering in waves.
Brodogradnja, 2017
To assess the manoeuvrability of ships in shallow water at the early design stage, reliable simul... more To assess the manoeuvrability of ships in shallow water at the early design stage, reliable simulation models which present shallow water effect are required. However, studies on the manoeuvrability of ship at low speeds in shallow water have been performed less than manoeuvrability in deep water. Also, the limitation of model that the effects of the keel clearance on manoeuvrability are applied to has been validated through previous studies. In this study, the manoeuvrability characteristics of the ship sailing in shallow water at low speed are evaluated by applying the mathematical model considering the shallow water effect. And the sensitivity analysis on shallow water manoeuvring simulation is performed in order to determine hydrodynamic derivatives which are necessary to be derived exactly due to the limitation of the shallow water model used in previous studies. Through this study, it could be confirmed that great importance of estimation of manoeuvrability could be found through the sensitivity index factor of hydrodynamic derivatives changing in the situation operating the shallow water at low speed.
J. Navig. Port Re, 2020
In recent years, there have been concerted efforts toward predicting ship maneuvering in shallow ... more In recent years, there have been concerted efforts toward predicting ship maneuvering in shallow water since the majority of ship' s accidents near harbors commonly occur in shallow and restricted waters. Enhancement of ship maneuverability at the design stage is crucial in ensuring that a ship navigates safely. However, though challenging, establishing the mathematical model of ship maneuvering motion is recognized as crucial toward accurately predicting the assessment of maneuverability. This paper focused on a study on sensitivity analysis of the hydrodynamic coefficients on the maneuverability prediction of KVLCC2 in shallow waters. Hydrodynamic coefficients at different water depths were estimated from the experimental results conducted in the square tank at Changwon National University (CWNU). The simulation of standard maneuvering of KVLLC2 in shallow waters was compared with the results of the Free Running Model Test (FRMT) in shallow waters from other institutes. Additionally the sensitivity analysis of all hydrodynamic coefficients was conducted by deviating each hydrodynamic derivative from the experimental results. The standard maneuvering parameters including turning tests and zigzag maneuvers were conducted at different water depths and their effects on the standard maneuvering parameters were assessed to understand the importance of different derivatives in ship maneuvering in shallow waters.