2024-10-11-中国船级社-2024集装箱船加速度响应直接预报指南_18页_1mb

报告摘要

Purpose: To provide a direct calculation method for forecasting acceleration responses of containers on ships during navigation, aiding in reducing shedding risks; it serves as a technical basis for operational restrictions.
Applicability: Affects ships over 24m in length, specifically container ships. CCS notation can be applied to ships meeting the guideline's requirements.
Key Definitions: Defines container ship, model basin tests, wind tunnel tests, and numerical calculations (based on CFD with validation).
Documentation Required: Submission of ship drawings (lines plans, layout, loading manual, container arrangements, etc.) for CCS verification.

General Approach: Accurate forecasting of container acceleration requires evaluating ship motions (sloshing and parametric roll). Validated through model basin tests or numerical simulations.
Motion Assessment: Involves harmonic motion (roll) and parametric roll; wave conditions include irregular waves with specified spectra (JONSWAP or similar), analyzed for different sea states and ship speeds.
Acceleration Impact: Focuses on transverse acceleration's effect on container loads; longitudinal and vertical accelerations have lesser impact.
Numerical Methods: Uses CFD or potential flow theory; model results must be within ±25% accuracy for reported values.

Requirements: Accurate inertia values (roll inertia) are crucial for precise acceleration prediction.
Calculation Method: Sum of inertia components from superstructure, cargo (containers), liquids, personnel, and added inertia; direct methods involve discrete modeling or empirical formulas based on ship dimensions.

Importance: For acceleration prediction accuracy, roll damping must account for viscous effects; it affects linear and third-order damping coefficients.
Obtainment: Through model basin tests (free decay with initial angles) or numerical CFD simulations, often using empirical formulas if data is limited.

Impact: Wind loads can influence roll motion and acceleration; recommendations include calculating both steady and gust loads, with simplified assumptions for application.

Purpose: To reduce shedding risks based on acceleration forecasts; defines safe operating conditions.
Implementation: Can be via a manual or onboard software; specifies limitations on wave heights, headings, speeds, and maximum container masses based on loads. Software must be validated for precision.

展开完整摘要