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KR-102961324-B1 - METHOD FOR HULL FORM VARIATION OF SHIPS WITH DISCONTINUOUS FORM

KR102961324B1KR 102961324 B1KR102961324 B1KR 102961324B1KR-102961324-B1

Abstract

The present invention relates to a method for converting the hull shape of a ship having discontinuous features, and more specifically, to a method for converting the hull shape of a ship having discontinuous features such as a knuckle line or chine that can be easily converted. To this end, the present invention is characterized by comprising: a first step in which, when the shape of a hull is input, a plurality of discontinuous lines existing in the hull are defined; a second step in which a plurality of design variables to be used for linear transformation among the defined discontinuous lines are defined; and a third step in which the corresponding discontinuous lines and linear shape are transformed by changing the defined design variables.

Inventors

  • 박동우
  • 이종현
  • 박정윤

Assignees

  • 동명대학교 산학협력단

Dates

Publication Date
20260507
Application Date
20231222

Claims (5)

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  3. A first step in which, when the shape of the hull is input, a plurality of discontinuous lines existing in the hull are defined; A second step in which a plurality of design variables to be used for linear transformation among the discontinuous lines defined above are defined; and A third step in which the corresponding discontinuous line and linearity are transformed by changing the design variables defined above; including, The discontinuous line defined in the first step above is a line including the knuckleline or chine of the hull, and The design variables defined in the second step above are selected for linear transformation, and In the case where the above hull is a catamaran with asymmetrical inner and outer shapes, the above design variables are, In_Bot design variables and Out_Bot design variables for shape transformation of the inner line (In_Bot line) and outer line (Out_Bot line) of the bottom of the above hull, In_Mid design variables and Out_Mid design variables for shape transformation of the inner line (In_Mid line) and outer line (Out_Mid line) of the draft portion of the above hull, and A method for transforming the hull shape of a ship having a discontinuous shape, characterized by including a Mid_H design variable for transforming the height at the point where the above In_Mid line and Out_Mid line meet the Forward Perpendicular (FP) and transforming the shape of the transom.
  4. A first step in which, when the shape of the hull is input, a plurality of discontinuous lines existing in the hull are defined; A second step in which a plurality of design variables to be used for linear transformation among the discontinuous lines defined above are defined; and A third step in which the corresponding discontinuous line and linearity are transformed by changing the design variables defined above; including, The discontinuous line defined in the first step above is a line including the knuckleline or chine of the hull, and The design variables defined in the second step above are selected for linear transformation, and If the above hull is a monohull, the above design variables are, Bot design variables for shape transformation of the bottom line (Bot line) of the above hull, Mid_In design variables and Mid_Out design variables for shape transformation of the inner line (Mid_In line) and outer line (Mid_Out line) at the center of the above-mentioned hull, and A method for transforming the hull shape of a ship having a discontinuous shape, characterized by including Top_In design variables and Top_Out design variables for transforming the shape of an inner line (Top_In line) and an outer line (Top_Out line) in a part located above the center line of the hull.
  5. A first step in which, when the shape of the hull is input, a plurality of discontinuous lines existing in the hull are defined; A second step in which a plurality of design variables to be used for linear transformation among the discontinuous lines defined above are defined; and A third step in which the corresponding discontinuous line and linearity are transformed by changing the design variables defined above; including, The discontinuous line defined in the first step above is a line including the knuckleline or chine of the hull, and The design variables defined in the second step above are selected for linear transformation, and In the case where the above hull is a catamaran with symmetrical inner and outer shapes, the above design variables are, Bot design variables for shape transformation of the bottom line (Bot line) of the above hull, Mid design variables for shape transformation of the centerline (Mid line) of the above-mentioned hull, and A method for transforming the hull shape of a ship having a discontinuous shape, characterized by including a Top design variable for transforming the shape of a line (Top line) located above the center line of the hull.

Description

Method for Hull Form Variation of Ships with Discontinuous Form The present invention relates to a method for converting the hull shape of a ship having discontinuous features, and more specifically, to a method for converting the hull shape of a ship having discontinuous features such as a knuckle line or chine that can be easily converted. As interest in the environment grows day by day, regulations on greenhouse gas emissions from ships are also becoming increasingly strict. Accordingly, various methods are being attempted to improve the operational efficiency of ships; among these, the method of reducing fuel consumption by deriving high-efficiency hull designs has been a fundamental and significant aspect of ship design from the past to the present. Once the major specifications of the ship, such as its length, width, draft, and displacement, are determined, the specific shape of the hull is determined, and the method of converting the hull shape from the existing mother ship is mainly used. Ship hulls typically feature smooth curved surfaces with almost no discontinuities, or shapes that are relatively flat due to the presence of discontinuous features such as knuckles and chines; among these, for hulls with discontinuous features, hull transformation is possible by modifying the shape of the line where the discontinuities occur. In this case, the conventional method for finding the optimal shape of discontinuous lines and hulls involves the line designer modifying the shape by individually adjusting the positions of interpolate points or control points, or curvatures, on the line. This method may be constrained by design personnel and design time, and has the problem of human error. FIG. 1 is a flowchart illustrating a method for transforming the hull shape of a ship having a discontinuous shape according to the present invention. FIG. 2 is a drawing showing the discontinuous line of a hull defined in the method for transforming the hull shape of a catamaran, that is, a ship having a discontinuous shape according to the present invention, i.e., a ship with asymmetric inner and outer shapes. FIG. 3 is a diagram showing the state of changing In_Bot and Out_Bot design variables in a method for transforming the hull shape of a ship having discontinuous shapes according to the present invention. FIGS. 4a and 4b are drawings showing the state of changing the Mid_H design variable in a method for transforming the hull shape of a ship having a discontinuous shape according to the present invention. FIG. 5 is a diagram showing the state of changing In_Mid and Out_Mid design variables in a method for transforming the hull shape of a ship having a discontinuous shape according to the present invention. Figures 6a and 6b are drawings showing examples of control point movement in a ship and a plane in which the hull has a smooth curved shape. FIG. 7 is a diagram showing the hull shape before conversion and the converted hull shape in which each design variable is changed to the minimum and maximum values of the conversion range when the method for converting the hull shape of a ship having a discontinuous shape according to the present invention is applied. FIG. 8 is a drawing showing the discontinuous line of the hull defined in the method for transforming the hull shape of a ship having a discontinuous shape according to the present invention, that is, a single-hull ship. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to the description, the advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the attached drawings. Furthermore, it should be noted that the terms used in this specification are for describing the embodiments and are not intended to limit the present invention; that singular forms of such terms include plural forms unless specifically stated otherwise in the text, and that words indicating direction in the description are intended to aid in understanding the description and may change depending on the context. In addition, the present invention applies a 3D shape deformation technique based on NURBS (Non-Uniform Rational B-Spline) surfaces for shape transformation of the hull, which allows for the smooth construction of a hull with many curved surfaces by moving control points that constitute the surface to deform the shape, and has the advantage of easily transforming the shape by rearranging control points of the hull surface generated by the NURBS surface. Due to the characteristics of ships, such as those with hulls constructed from aluminum plates that primarily feature straight lines, a change in the shape of the knuckleline causes the surface with that line as a boundary to deform. Therefore, a hull shape transformation technique using design variables was implemented by defining desig