📦 Resource excel

Marine Hydrodynamics Calculation Excel Template

A Marine Hydrodynamics Calculation Excel Template is a structured spreadsheet tool designed to perform standardized hydrodynamic computations relevant to marine and offshore engineering, such as wave forces, vessel motion responses, added mass, damping coefficients, and resistance estimation. It integrates empirical, semi-empirical, and analytical methods—often aligned with ITTC, DNV, or IMO guidelines—to support preliminary design, performance assessment, and regulatory compliance. The template typically features modular worksheets, input validation, unit conversion, and visual output (e.g., charts of RAOs or wave spectra).

📖 Overview

Marine hydrodynamics involves the study of fluid behavior around marine structures and vessels, governed by Navier-Stokes equations, potential flow theory, and boundary layer dynamics. Excel templates simplify application of these principles by embedding validated approximations—such as Morison’s equation for slender body wave loading, linear wave theory (Airy waves), and strip theory for seakeeping analysis—into accessible computational workflows. These templates serve as pedagogical aids, rapid feasibility tools, and first-pass engineering checklists, especially where high-fidelity CFD or time-domain simulation is impractical. Key design considerations include dimensional consistency (SI vs. Imperial units), non-dimensional parameter handling (e.g., Froude, Reynolds, and Keulegan-Carpenter numbers), and uncertainty awareness—since Excel-based calculations inherently assume idealized conditions and neglect nonlinearities, viscosity effects, or complex geometry interactions unless explicitly extended. Validation against experimental data (e.g., MARIN or HSVA model test results) or industry-standard software (like WAMIT, OrcaFlex, or MOSES) is strongly recommended before deployment in critical design phases.

📑 Key Components

1 Wave Load Calculator (Morison & Diffraction)
2 Seakeeping Response Amplitude Operator (RAO) Generator
3 Hull Resistance Estimator (Holtrop-Mennen & ITTC 1957 Line)

🎯 Applications

  • Preliminary design of offshore platforms and floating wind turbines
  • Vessel seakeeping and operability analysis for mission planning
  • Regulatory compliance checks (e.g., DNV-RP-C205 for environmental loads)

📐 Key Formulas

Morison Equation (In-line Wave Force)

F = 0.5 * ρ * Cd * D * |u| * u + ρ * Ca * π * D² / 4 * du/dt

Computes total in-line hydrodynamic force on a slender cylindrical member due to wave-induced velocity (u) and acceleration (du/dt); includes drag (Cd) and inertia (Ca) components.

ITTC 1957 Standard Ship Resistance Line

C_T = C_F + C_R; C_F = 0.075 / (log10(Rn) − 2)^2; Rn = V * L / ν

Estimates total hull resistance coefficient (C_T) from frictional (C_F) and residual (C_R) components using Reynolds number (Rn), water kinematic viscosity (ν), ship speed (V), and length (L).

Linear Airy Wave Height–Period Relationship

c = √(g * L / (2π)) = g * T / (2π) * tanh(2π * d / L)

Relates phase speed (c), wave period (T), wavelength (L), water depth (d), and gravitational acceleration (g); used to compute dispersion and wave kinematics.

🔗 Related Concepts

Potential Flow Theory Added Mass and Radiation Damping Wave Spectra (JONSWAP, Pierson-Moskowitz)

📚 References

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