Ship Simulation Workbench

Bhushan Taskar [bhta@mek.dtu.dk]Supervisor: Poul Andersen

Skibsteknisk Selskab 4 marts 20192/44 DTU Mechanical Engineering, Technical University of Denmark

Why Workbench?

Resistance Propulsion Engine Weather

Calm water resistanceAdded 

resistance

Propeller designOpen water 

curvesThrust 

deductionWake fraction

MCR powerMax. rpmSea margin

Engine margin

Typical weather for a given route

Vessel Performance

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Performance in a Seaway

Route Simulations

Total Resistance

How? Creating a library of functions

Calm water Resistance

AddedResistance

Wind and other…

Weather RoutePropeller curves

Engine model

Voluntary speed loss

Fuel consumption

Emissions

Fouling

Ship motions

Skibsteknisk Selskab 4 marts 20194/44 DTU Mechanical Engineering, Technical University of Denmark

What does it do?Simulates a ship on a particular route in a given weather

Ship Route Weather

Hull particularsL, B, T, CB, design speed, 

wetted surface 

Propeller designDia., no of blades, P/D, 

blade area ratio

PropulsionThrust deduction, wake 

fraction

EnginePower, rpm

Choose from available/ 

Define new route

User Defined/ Use weather data

Available Routes

Example Calculation

From Los Angeles to OsakaIn average weather of January

Skibsteknisk Selskab 4 marts 20197/44 DTU Mechanical Engineering, Technical University of Denmark

Total Resistance

Ship Speed

Power

Propeller

RPS

Total distance = 4800 NMVoyage time = 13.6 daysFuel consumption = 2032 mt

Skibsteknisk Selskab 4 marts 20198/44 DTU Mechanical Engineering, Technical University of Denmark

Simulations with Engine Model

Total Resistance

Ship Speed

Power

Propeller

RPS

Limited Power

Reduced speed

Skibsteknisk Selskab 4 marts 20199/44 DTU Mechanical Engineering, Technical University of Denmark

Engine Limits

Skibsteknisk Selskab 4 marts 201910/44 DTU Mechanical Engineering, Technical University of Denmark

Total Resistance

Ship Speed

Power

Propeller

RPS

Simulation options

Skibsteknisk Selskab 4 marts 201911/44 DTU Mechanical Engineering, Technical University of Denmark

Available methods• Calm water resistance

– Holtrop, Hollenbach, Guldhammer methods– User specified resistance curve (CFD, Model tests, Potential flow, …)

• Propeller open water data– B-series propellers– User specified open water curves

• Added resistance– DTU and ITTC methods– User specified added resistance

• Default weather and routes– Weather: Monthly average of each month– Routes: busy shipping lanes

Skibsteknisk Selskab 4 marts 201912/44 DTU Mechanical Engineering, Technical University of Denmark

Advantages• Easy to setup basic simulations

• Coded in Python – Open-source programing language– Increasingly popular– Many students at DTU learning Python

• Basic methods available for research/project

• Publish workbench module along with research > available to others

• Users can get access to new developments

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Research using Workbench• Effect of different added resistance formulations

• Added resistance only in head sea vs all wave conditions

Skibsteknisk Selskab 4 marts 201914/44 DTU Mechanical Engineering, Technical University of Denmark

Other possible usages• Effect of energy saving devices

• Performance of ship with sails or Flettner rotors

• Effect of different routes – weather routing

• Different operating profiles – speed variations

• Calculate sea margin, engine margin

• Emissions and performance using different engine types

• Paint and fouling related studies

Ship Simulation Workbench

Bhushan Taskarbhta@mek.dtu.dk