This study investigates the resistance of a transport ship navigating in level ice by conducting a series of model tests in an ice tank at Tianjin University. The laboratory-scale model ship was mounted on a rigid car...This study investigates the resistance of a transport ship navigating in level ice by conducting a series of model tests in an ice tank at Tianjin University. The laboratory-scale model ship was mounted on a rigid carriage using a one-directional load cell and then towed through an ice sheet at different speeds. We observed the ice-breaking process at different parts of the ship and motion of the ice floes and measured the resistances under different speeds to determine the relationship between the ice-breaking process and ice resistance. The bending failure at the shoulder area was found to cause maximum resistance. Furthermore, we introduced the analytical method of Lindqvist （1989） for estimating ice resistance and then compared these calculated results with those from our model tests. The results indicate that the calculated total resistances are higher than those we determined in the model tests.展开更多
Physical testing of large-scale ship models at sea is a new experimental method.It is a cheap and reliable way to research the environment adaptability of a ship in complex and extreme wave conditions.It is necessary ...Physical testing of large-scale ship models at sea is a new experimental method.It is a cheap and reliable way to research the environment adaptability of a ship in complex and extreme wave conditions.It is necessary to have a stable experimental system for the test.Since the experimental area is large, a remote control system and a telemetry system are essential, and were designed by the authors.An experiment was conducted on the Songhuajiang River to test the systems.The relationship between the model's speed and its electromotor's revolutions was also measured during the model test.The results showed that the two systems make it possible to carry out large-scale model tests at sea.展开更多
The inclining experiment is the only regulatory tool to assess ship stability. This experiment is a time consuming process for both real-life tests and ship model experiments. The difficulty is mainly due to a bias in...The inclining experiment is the only regulatory tool to assess ship stability. This experiment is a time consuming process for both real-life tests and ship model experiments. The difficulty is mainly due to a bias in the measurement of heel angle. Nowadays, digital inclinometers are available, but they are expensive. In this study, the use of a smartphone application is presented for ship inclination and rolling-period tests. The idea consists of using accelerometer and gyroscope sensors built into the current smartphones for the measurements. Therefore, some experiments are carried out on an example trawler model to exhibit the uses and advantages of this method. The obtained results are in good agreement with those provided from the pendulum method and natural roll-period test. This application is new, easy, and more accurately assesses metacentric height during the inclining and rolling-period tests.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos. 51179123 and 51279131
文摘This study investigates the resistance of a transport ship navigating in level ice by conducting a series of model tests in an ice tank at Tianjin University. The laboratory-scale model ship was mounted on a rigid carriage using a one-directional load cell and then towed through an ice sheet at different speeds. We observed the ice-breaking process at different parts of the ship and motion of the ice floes and measured the resistances under different speeds to determine the relationship between the ice-breaking process and ice resistance. The bending failure at the shoulder area was found to cause maximum resistance. Furthermore, we introduced the analytical method of Lindqvist （1989） for estimating ice resistance and then compared these calculated results with those from our model tests. The results indicate that the calculated total resistances are higher than those we determined in the model tests.
基金Supported by the National Defense Foundation under Grant No.51414030204CB0109
文摘Physical testing of large-scale ship models at sea is a new experimental method.It is a cheap and reliable way to research the environment adaptability of a ship in complex and extreme wave conditions.It is necessary to have a stable experimental system for the test.Since the experimental area is large, a remote control system and a telemetry system are essential, and were designed by the authors.An experiment was conducted on the Songhuajiang River to test the systems.The relationship between the model's speed and its electromotor's revolutions was also measured during the model test.The results showed that the two systems make it possible to carry out large-scale model tests at sea.
文摘The inclining experiment is the only regulatory tool to assess ship stability. This experiment is a time consuming process for both real-life tests and ship model experiments. The difficulty is mainly due to a bias in the measurement of heel angle. Nowadays, digital inclinometers are available, but they are expensive. In this study, the use of a smartphone application is presented for ship inclination and rolling-period tests. The idea consists of using accelerometer and gyroscope sensors built into the current smartphones for the measurements. Therefore, some experiments are carried out on an example trawler model to exhibit the uses and advantages of this method. The obtained results are in good agreement with those provided from the pendulum method and natural roll-period test. This application is new, easy, and more accurately assesses metacentric height during the inclining and rolling-period tests.
