Streamline Digitalization of Ship Model Ink Paint Test and Application on Bilge Keel Design

  • 林 禹棟

Student thesis: Doctoral Thesis

Abstract

The ship model test plays an important role in ship design The ink streamline obtained by the ink paint test shows the streamline around the hull during navigation However the test results can only be studied by photos or videos currently which can’t really show the influences between ship hull and streamline In this study we try to digitalize testing photos to 3D model by image processing and make further analysis and applications This study is divided into three parts In the first part we establish a system for ink paint test streamline digitalization First we write a streamline identification program In the program Gaussian filter is used for photo preprocessing and identify the ink streamline by HSV color value As we define the target area the coordinates of the ink streamline can be output Then we establish a process of taking test photos which include how to arrange markers on the ship model measuring the position of the marks and designing the photograph environment Finally as we get the coordinates of the ink streamline we transfer the ink streamlines into 3D software by projecting the coordinates to the 3D ship model In the second part we do mathematical analysis about the relationship between the streamline slope and the hull shape Then we calculate the fluid dynamic pressure distribution by CFD software and study the relationship between streamline and pressure distribution Finally we compare the CFD streamline with the ink streamline and analyze the difference In the third part combine the first two parts We use the digitalize system as the basis of designing the ship's bilge keel Then verified the ship resistance added by this design method is smaller After that we also calculate the stability of the ship to make sure the bilge keel can make positive effect when adding on
Date of Award2020
Original languageEnglish
SupervisorChung-Hung Lin (Supervisor)

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