Volume 03 - Issue 02 (February 2019)


Title: Tuning the Rigging and Spars to Ensure Maximum Safety of Sailing Vessels
Authors: Dimitar Dimitrakiev, Yuriy Dachev, Ivo Lazarov
Source: International Journal of Latest Research in Engineering and Management, pp 01 - 05, Vol 03 - No. 02, 2019
Abstract: Sailing vessels cannot sail straight into the wind, thus a voyage to a given destination point on one course only is rendered virtually impossible. The ship’s master must sail close-hauled and change tacks periodically in order to get from point A to point B. This technique of sailing into the wind is known as "tacking". The sailing maneuver of tacking involves sailing close-hauled (beating to windward), sailing as close to the wind as possible, in order to have the least tack changes and least time and distance to overcome. The number and length of tacks depend on the distance between the starting and ending points of the route, the limits of the harbour area, the navigation situation and the change in wind direction during the passage. If sailing is to be carried out in tight quarters, the vessel must shift tacks every time she gets into proximity of the shore or may leave the fairway. If sailing takes place in high seas, the number of tacks tends to be less. A long tack ensures sailing the shortest distance to the mark.If there are navigational obstructions along the route, the vessel must be ready to short tack to avoid them. Sailing on a close-haul implies a certain angle of the sails to the wind and a certain ship’s course into the wind. Finding the optimal course for the vessel means reaching the destination point the fastest way, making good maximum speed into the wind. The mean speed achieved by a sailing vessel is a good assessment criterion for the quality of sailing. Issues related to the optimal routeing of sailing vessels have been widely discussed in many researches. Most studies have focused on the trimming of sails to ensure top speed. Little consideration has been given to the problem of ship’s speed alterations following different heeling angles due to different tuning of the rigging and its impact on ship’s stability, irrespective of the maximum speed reached at a given tack. The present paper proposes a solution to this problem.
Keywords: close-hauled, safety, sailing vessel, tacking.
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Title: Wave Solutions of The Benjamin-Bona-Mahony’s Equation in Weighted Sobolev Spaces
Authors: Hernán Oscar Cortez Gutierrez, Milton Milciades Cortez Gutiérrez, Lenin Cabracancha Montesinos, Luis Garcia Ramos
Source: International Journal of Latest Research in Engineering and Management, pp 06 - 10, Vol 03 - No. 02, 2019
Abstract: We explore the conformable fractional BBM equation. The question of the center of mass of the wave solution is analyzed with the existence of solution for the Benjamin-Bona- Mahony’ s equation (BBM) in a weighted Sobolev space. Similar results of the center of energy in DNA breathing is observed using Klein Gordon equations and Floquet theory.
Keywords: soliton,, center of mass, DNA breathing, Klein Gordon, Floquet theory
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