Ship Torque Analysis for Separating Propeller and Hull Surface Effects

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Solution Overview

Problem

Conventional technologies fail to distinguish between factors of ship performance deterioration derived from the propeller surface state and those from the hull surface state, necessitating a method to evaluate these factors separately.

Innovation Solution

An analysis device that determines and outputs separate torque coefficients for propeller and hull surface states using a first and third determination means, with additional means for generating maintenance effect information based on past results and sailing conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional technologies are used to evaluate ship performance deterioration, then the evaluation can be performed, but the factors from propeller surface state and hull surface state cannot be distinguished

Engineering Contradiction:
Improveevaluation precisionVSAvoidinformation on factor distinction
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent segments the ship performance deterioration evaluation into distinct components: propeller surface state factors and hull surface state factors. By calculating separate torque coefficients (first torque coefficient for propeller, second torque coefficient for hull) and determining their individual contributions to performance deterioration, the system enables precise distinction between these factors that were previously merged in conventional evaluations.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If separate evaluation of propeller and hull factors is implemented, then factor distinction is achieved, but device complexity increases

Engineering Contradiction:
Improvefactor distinction precisionVSAvoidanalysis device complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The analysis device performs multiple functions using a unified approach: it evaluates overall ship performance deterioration, identifies propeller-specific factors, identifies hull-specific factors, and determines their respective contributions. By using a single device that integrates these multiple evaluation functions rather than separate devices for each factor, the patent achieves factor distinction while managing device complexity through multi-functionality.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4596390A1Analytical device and program
Publication Date: 2025.08.06 NIPPON YOOSEN KABUSHIKI KAISHA
  • EP4596390A1 patent drawingFigure 1
  • EP4596390A1 patent drawingFigure 2
  • EP4596390A1 patent drawingFigure 3

AI summary

An analysis device (40) includes: a first determination means (412) configured to determine an amount of increase in a first torque coefficient of a propeller caused by a change in a surface state of an entire ship including a hull and the propeller; a first acquisition means (411) configured to acquire a value indicating a surface state of the propeller; a second determination means (413) configured to determine an amount of increase in a second torque coefficient of the propeller caused by a change in the surface state of the propeller, with use of the value; a third determination means (414) configured to determine an amount of increase in a third torque coefficient of the propeller caused by a change in a surface state of the hull, with use of the amount of increase in the first torque coefficient and the amount of increase in the second torque coefficient; and an output means (46) configured to output the amount of increase in the second torque coefficient and the amount of increase in the third torque coefficient.