The Experts below are selected from a list of 18 Experts worldwide ranked by ideXlab platform
Pichumani Vinodh - One of the best experts on this subject based on the ideXlab platform.
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Prediction of added resistance in waves: Numerical method with an experimental setup
2017Co-Authors: Pichumani VinodhAbstract:The Shipping industry constantly strives to improve – allowing productivity and sustainability to be tapped in the best possible way. The concept of sail-assisted propulsion of modern Ships is a major step in that direction. It basically adds the natural advantage of direction-dependent wind force to the conventional primary drive in the form of a diesel engine. The idea of using sails and natural wind as a means of transport is richly derived from maritime history. An effective combination with modern technology would massively help in economic Ship transportation with largely reduced carbon footprints. This thesis is a step closer to that goal. The focus here is to describe the added wave resistance acting on a sail-assisted Ship model, Ecoliner. There are two major technical aspects to this general situation: 1) description of the hydrostatic stability and response of sails to winds 2) the hydrodynamic investigation of loads effects on the hullPoint 2 is the obvious focus of attention in this work. This thesis is a follow-up of an experiment done at TU Delft, November 2013 to determine the influence of Heel and leeway on added wave resistance on the said Ship model.Diffraction method based numerical analyses have been carried out to establish the added resistance for three different Ship Heel angles and three leeway angles over two different sailing speeds. Validation of the performed experiment is done as well as new findings regarding the sensitivity of the model variables are reported.The highest leeway angle of 9 degrees, in particular, is seen to have a significant effect in the increasing the added resistance. This effect was previously not captured by experiments and helps give an overview on which parameters the Ecoliner Ship’s performance is more sensitive to. Effect of constraining or allowing roll is also found to be an especially important parameter. The margin of difference between analysis and experiment results improves by about 20 to 25\% after a proper analysis of roll hydrodynamics and putting that factor in.This work will hopefully be a stepping stone in further research endeavours in this field concerning optimizing Ecoliner as an end market product. Recommendations are given in this report for specific follow-up work in both the analytical as well as the experimental domain for the hull-related study.Offshore and Dredging Engineerin
Vinodh Pichumani - One of the best experts on this subject based on the ideXlab platform.
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Prediction of added resistance in waves: Numerical method with an experimental setup
2017Co-Authors: Vinodh PichumaniAbstract:The Shipping industry constantly strives to improve – allowing productivity and sustainability to be tapped in the best possible way. The concept of sail-assisted propulsion of modern Ships is a major step in that direction. It basically adds the natural advantage of direction-dependent wind force to the conventional primary drive in the form of a diesel engine. The idea of using sails and natural wind as a means of transport is richly derived from maritime history. An effective combination with modern technology would massively help in economic Ship transportation with largely reduced carbon footprints. This thesis is a step closer to that goal. The focus here is to describe the added wave resistance acting on a sail-assisted Ship model, Ecoliner. There are two major technical aspects to this general situation: 1) description of the hydrostatic stability and response of sails to winds 2) the hydrodynamic investigation of loads effects on the hull Point 2 is the obvious focus of attention in this work. This thesis is a follow-up of an experiment done at TU Delft, November 2013 to determine the influence of Heel and leeway on added wave resistance on the said Ship model. Diffraction method based numerical analyses have been carried out to establish the added resistance for three different Ship Heel angles and three leeway angles over two different sailing speeds. Validation of the performed experiment is done as well as new findings regarding the sensitivity of the model variables are reported. The highest leeway angle of 9 degrees, in particular, is seen to have a significant effect in the increasing the added resistance. This effect was previously not captured by experiments and helps give an overview on which parameters the Ecoliner Ship’s performance is more sensitive to. Effect of constraining or allowing roll is also found to be an especially important parameter. The margin of difference between analysis and experiment results improves by about 20 to 25\% after a proper analysis of roll hydrodynamics and putting that factor in. This work will hopefully be a stepping stone in further research endeavours in this field concerning optimizing Ecoliner as an end market product. Recommendations are given in this report for specific follow-up work in both the analytical as well as the experimental domain for the hull-related study.
C.b. Barrass - One of the best experts on this subject based on the ideXlab platform.
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Angle of loll
Ship Stability for Masters and Mates, 2012Co-Authors: C.b. Barrass, D.r. DerrettAbstract:When a Ship with negative initial metacentric height is inclined to a small angle, the righting lever is negative, resulting in a capsizing moment. This effect makes the Ship Heel still further. At a large angle of Heel, the centre of buoyancy moves further out the low side and the force of buoyancy does not act vertically upwards. If, by Heeling still further, the centre of buoyancy can move out far enough to lie vertically under the centre of gravity (G), the righting lever and thus the righting moment, will be zero. The angle of Heel at which this occurs is referred to as the angle of loll and may be defined as the angle to which a Ship with negative initial metacentric height lies at rest in still water. If the Ship is inclined to an angle greater than the angle of loll, the righting lever will be positive, giving a moment to return the Ship to the angle of loll. The Ship will oscillate about the angle of loll instead of the upright. At angles of Heel less than the angle of loll, the righting levers are negative.
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Chapter 31 – Angle of loll
Ship Stability for Masters and Mates, 2006Co-Authors: C.b. BarrassAbstract:Publisher Summary When a Ship with negative initial metacentric height is inclined to a small angle, the righting lever is negative, resulting in a capsizing moment. This effect makes the Ship Heel still further. At a large angle of Heel, the centre of buoyancy moves further out the low side and the force of buoyancy does not act vertically upwards. If, by Heeling still further, the centre of buoyancy can move out far enough to lie vertically under the centre of gravity (G), the righting lever and thus the righting moment, will be zero. The angle of Heel at which this occurs is referred to as the angle of loll and may be defined as the angle to which a Ship with negative initial metacentric height lies at rest in still water. If the Ship is inclined to an angle greater than the angle of loll, the righting lever will be positive, giving a moment to return the Ship to the angle of loll. The Ship will oscillate about the angle of loll instead of the upright. At angles of Heel less than the angle of loll, the righting levers are negative.
D.r. Derrett - One of the best experts on this subject based on the ideXlab platform.
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Angle of loll
Ship Stability for Masters and Mates, 2012Co-Authors: C.b. Barrass, D.r. DerrettAbstract:When a Ship with negative initial metacentric height is inclined to a small angle, the righting lever is negative, resulting in a capsizing moment. This effect makes the Ship Heel still further. At a large angle of Heel, the centre of buoyancy moves further out the low side and the force of buoyancy does not act vertically upwards. If, by Heeling still further, the centre of buoyancy can move out far enough to lie vertically under the centre of gravity (G), the righting lever and thus the righting moment, will be zero. The angle of Heel at which this occurs is referred to as the angle of loll and may be defined as the angle to which a Ship with negative initial metacentric height lies at rest in still water. If the Ship is inclined to an angle greater than the angle of loll, the righting lever will be positive, giving a moment to return the Ship to the angle of loll. The Ship will oscillate about the angle of loll instead of the upright. At angles of Heel less than the angle of loll, the righting levers are negative.
Yi-zhou Ren - One of the best experts on this subject based on the ideXlab platform.
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Numerical Simulations of Continuous Icebreaking Process With Different Heel Angles in Level Ice
Volume 8: Polar and Arctic Sciences and Technology; Petroleum Technology, 2018Co-Authors: Feng Wang, Zao-jian Zou, Hai-peng Guo, Yi-zhou RenAbstract:Based on cohesive element method (CEM), the continuous icebreaking process with different Heel angles in level ice are simulated in this paper. The simulations are established in FEM software LS-DYNA and an icebreaking tanker - MT Uikku is assumed advancing with the certain Heel angle in level ice. Firstly, the comparisons are made between the simulations and the model tests for the cases with zero Heel angle. A good agreement is obtained between the simulated and measured data. Then the effects of different Heel angles on ice resistance and ice breaking patterns are investigated and analyzed. The results show that ice resistance, average ice breaking length and average broken channel width present increasing trends with the increase of Ship Heel angle. The applied methods show a wide prospect to predict ice loads on marine structures in the level ice and simulate the ice-structure interaction process.