CFD’s role in improving your ship’s energy efficiency

CFD’s role in improving your ship’s energy efficiency

28 September 2021 • 15:00-15:45 BST

#marinepropulsion

Part ofMarine PropulsionWebinar Week27-29 September 2021

Panellist documents

Page 2: Iulia Oprea, Wärtsilä NetherlandsPage 14: Dmitriy Ponkratov, Royal Institution of Naval ArchitectsPage 19: Mattia Brenner, Friendship Systems, GermanyPage 27: Keith Hutchinson, Safinah Group, UK

© Wärtsilä

THE ROLE OF CFD IN IMPROVING VESSEL ENERGY EFFICIENCYIULIA OPREA

TEAM LEADER CFD COMMERCIAL PROJECTS

WÄRTSILÄ MARINE POWER

© Wärtsilä 28-9-2021 The role of CFD in improving vessel energy efficiency / Iulia Oprea2

TABLE OF CONTENTS

1. Introduction and way of working

2. Validation

3. Vessels efficiency optimisation using CFD

• Required input data

• Resistance optimisation

• Propulsion optimisation

4. Advantages


INTRODUCTION

• Computational Fluid Dynamics (CFD) provides quantitative predictions of fluid-flow phenomena

based on the conservation laws

• Simulations have a vast history at Wärtsilä Propulsion

• CFD is used daily in the design of propulsion units


WAY OF WORKING

1. Propeller design (traditional route)

2. Propeller vicinity design (optimised

route for propeller)

3. Propeller-Hull design (optimised

route for propeller & hull)

2 13


VALIDATION

• Most of the open water CFD simulations are within ±1% compared to measurements.

• Deviations between CFD and measurements for resistance/self-propulsion are typically within ± 2%.


REQUIRED INPUT DATA

• A 3D-model of the ship* together with the rudder and other appendages is needed at the start of an

optimisation study (ship design input / collaboration)

• The optimisation study (OPTI Design) identifies improvements to the vessel propulsion configuration

and in some cases also hull lines. Changes can include:

• Propeller geometry and position

• Rudder geometry, deflection and positioning

• Brackets positioning and other appendices study

• Nozzle shape, if applicable

• Nozzle connection, if applicable

• Nozzle headbox, if applicable

• Alignment of different geometry components with the flow

*The most important aspect of the optimisation study is the mutual trust, the confidentiality,

and the acceptance of the involved parties to share 3D-geometries.


RESISTANCE OPTIMISATION

1. Geometrical components

• Hull, appendices and rudder

2. Flow improvement

• Wake field, wave patterns and

streamlines

3. Performance

• Resistance reduction


OPTIMISATION EXAMPLE

• Hull lines improvement (ship design input) for resistance and wake field, bulk carrier example:

Optimised

Optimised

13% resistance

decrease

at 13 knots


PROPULSION OPTIMISATION

1. Geometrical components

• Struts, headboxes, propeller, nozzle etc. (shape and position)

2. Flow improvement

• Backflow, separation, vortices, pressure pulses etc.

3. Performance

• Efficiency increase and power reduction


OPTIMISATION EXAMPLES

• Open propellers• Propeller clearance

• Rudder connection

• Shaft line alignment

• Propeller design

• Nozzle propellers• Nozzle shape

• Nozzle connections

• Rudder connection

• Shaft line alignment


• Thrusters• Unit position

• Connections/headbox

• OPTI DP (Dynamic Positioning)


Propeller, bulb and

rudder => ~3% decrease

in Pd

Propeller, rudder

bulb and keel bar =>

flow improvement

and 1% on Pd

Nozzle shape,

connection and keel

bar => flow

improvement and

2.5% on Pd Brackets alignment

Jet interaction with

thruster and hull


ADVANTAGES

• Delivers the optimal propeller configuration for the vessel

• Reduced model tests

• Identify potential issues before full scale sea trails

• Increased efficiency and power reduction delivering fuel saving (CII) and impacting EEDI (EEXI)

• Optimisation efficiency gains:

1. Propeller design 1-2%

2. Propeller vicinity design 4-5%

3. Propeller and hull design 10-15%

• What to expect in future optimisation:

• Optimisation techniques

• Operation profiles

• Sea states

• Manoeuvring and course keeping

CFD’s role in improving your ship’s energy efficiency28 September 2021

Dr Dmitriy Ponkratov JoRes Joint Research Project

Royal Institution of Naval Architects

2

28th ITTC, Wuxi, China, September 2017

Key message: Advanced CFD + Full-scale data = More reliable procedures for Propulsion!

IMO Resolution MEPC 334(76)

ANNEX 8

RESOLUTION MEPC.334(76)

(adopted on 17 June 2021)

2021 GUIDELINES ON SURVEY AND

CERTIFICATION OF THE ATTAINED ENERGY

EFFICIENCY EXISTING SHIP INDEX (EEXI)

4.2.8 The estimated speed-power curve obtained

from the tank test and/or numerical calculations

and/or the sea trial results calibrated by the tank

test should be reviewed on the basis of the

relevant documents in accordance with the EEDI

Survey and Certification Guidelines, the defined

quality standards (e.g. ITTC 7.5-03-01-02 and

ITTC 7.5-03-01-04 in their latest revisions) and the

verification of the numerical setup with parent hull

or the reference set of comparable ships.

4

2. JoRes1 – single screw vessel for PIV measurements

JoRes Joint Research project

Working together to build confidence in CFD

Thank you!

5

FRIENDSHIP SYSTEMS © 2021

Simulation-Driven Design of Ships

for optimal energy efficiency


CFD Becoming a Design Tool

Available computing power made using CFD much more feasible, even for complex cases

CFD – especially meshing – has become much easier to use

CFD is used much more and much earlier in the design process, making it a real design tool

CFD results can be used to gain knowledge about the product and to guide the design, especially in the critical early design stages

2


CFD Becoming a Design Tool

3

Traditional CADfor design, layout, assembly, manufacturing etc.

CFDfor design

CFDfor analysis and assessment

Phases of product development

CAx

Trend towards earlier employment of CFD and optimization

Upfront CAE

Upfront CAD

Upfront CFD

Upfront Optimization

Planning(markets &

requirements)

Concept design

Preliminary design

Detailed Design

Verification (digital & physical

prototype)Production


Process Automation

Next logical step is to automate the design process

“Form follows function”

Automated design exploration and optimization

– Lead to better and optimized designs

– Shorten development times and reduce design cycles

– Increase knowledge early in the design process

Needs

– A simulation tool that provides the required information

– A driver of the optimization process

– A suitable CAD for geometry variation

4


Process Automation

Next logical step is to automate the design process

“Form follows function”

Automated design exploration and optimization

– Lead to better and optimized designs

– Shorten development times and reduce design cycles

– Increase knowledge early in the design process

Needs

– A simulation tool that provides the required information

– A driver of the optimization process

– A suitable CAD for geometry variation

5


CAESES® | A Simulation-Driven Design Platform

6


Future Trends

Multi-objective

– Several operating conditions

– Operational profile

– Resistance and propulsion

Multi-disciplinary

– Hydrodynamics

– Stability

– Arrangements

– Etc.

Multi-component

– Ship hull

– Appendages

– Propulsors

7


Mattia Brenner

[email protected]

www.CAESES.com

The Industry Standardfor Ship Hull Optimization

CFD - perspective

of a ship designer

Keith W HutchinsonBEng(Hons) CEng CMarEng FRINA FIMarEST FSNAME

Senior Consultant - Whole Ship Design and Naval Arch

Professional Technical and Engineering Services

CFD - perspective of a ship designer, KW Hutchinson, Safinah Group

CFD’s role in improving your ship’s energy efficiency - Marine Propulsion Webinar Week, Riviera Marine Media, Online (RMM Webinar), United Kingdom, 28th September 2021 1

Introduction

1. Ship operation - efficiency drivers

2. Ship design - criteria and approach

3. Ship powering - attributes and considerations

4. Ship realisation - robust and optimal CFD

Questions … and maybe some answers!

Presentation Agenda

2

© FORCE

Technology


CFD’s role in improving your ship’s energy efficiency - Marine Propulsion Webinar Week, Riviera Marine Media, Online (RMM Webinar), United Kingdom, 28th September 2021

1. Ship operation - efficiency drivers

Regulatory drivers include:EU MRV – designed to measure and reduce CO₂ emissions (1st January 2018)

IMO MARPOL Annex VI - 0.5% global sulphur cap (1st January 2020)

IMO GHG Strategy (2018) - reduction carbon intensity: 40% next decade by 2030

50% total (70% inten) by 2050

- EEDI, efficiency criteria for new-build ships (2013 to 2025)

- EEXI, efficiency criteria for existing ships (1st January 2023)

- CII (operational efficiency) and SEEMP (management systems)

Other drivers include:Clean port operations - cold ironing, cleaner fuels

Focus on carbon footprint throughout supply chains

Public pressure for cleaner and eventually zero carbon fuels

Possible ‘plus points’:Reduced fuel cost, emissions and carbon tax advantages

Reduction first and through-life (maintenance) machinery costs

Reputational advantage of greater efficiency / cleaner fuels

3CFD - perspective of a ship designer, KW Hutchinson, Safinah Group


Synthesis (MODM)

Evolution Selection (MADM)

2. Ship design - criteria and approach

4

Strategic model

for ship design

‘Design Spiral’

(IL Buxton 1971)



Feasibility Studies

Concept Design

Basic Design (Pre-FEED)

Design to Class (FEED)

Detailed Design

Tests and Trials

Forensic Analyses

Global information,

optimisation (Shell),

evaluation (Engine) and

selection (Methodology)

ship design model (KW Hutchinson 1998)

Multiple Criteria

Decision Making

(MCDM)

Specification - Transportation capability and Service speed, range, etc.

Multiple, often conflicting, operational performance criteria:Dimensional Constraints

Cargo Handling requirements

Arrangement demands

Stability and Seakeeping

Manoeuvring / Positioning

Structural, Engineering systems

Statutory requirements, etc.

Trade-off, developed solution(s) must concurrently satisfy / optimise compliance

whilst maximising operational efficiency / minimising installed power (SMCR)

Iterative by nature of ship design, including design of propellers / engine selection:Production of highly efficient ship designs = holistic, cohesive, coordinated optimisation of design criteria

Optimal resistance / propulsion efficiency = ship designer + propulsor manufacturer + engine manufacturer

Key to robust and efficient ship designs = close, creative, collaborative relationships … “the three Cs”

Ship resistance elements:Hull - form, bow, stern, lubrication

Appendages - keels, rudders, fins

Deductions - chests, tunnels - doors

Weather - waves, wind - route(s)

Fouling*, etc. - coating, UV, ultrasonic

Ship propulsion elements:Hull efficiencies etc. - stern, ESDs

Propulsor(s)* - type, no, size, location

Transmission - shafting, gearing, PTO

Prime-movers - engines, gens/motors

Ship operation, bunker requirements and greenhouse gas (GHG) emissions:Operational Profile(s) - draughts / trims, activity / speeds, routes / ports, weather, in-service / cleaning

Fuel(s) - HFO, MDO, LNG, CH3OH, NH3, H2, Batteries, combination … and there production / generation!

Main and Auxiliary machinery – Engine type, scrubbers, SCRs, CO2 capture, etc.

3. Ship powering - attributes & considerations



Approach:Empirical

Methodical / Statistical

CFD codes

Numerical Model Tank?

Physical Model Tests

4. Ship realisation - robust and optimal CFD

Principal dimensions / particulars - evolution or revolution:Paramount driver on efficiency (resistance and propulsion), fuel costs (OPEX)

Dimensions and form ratios / coefficients optimised for minimum OPEX seldom

coincide with those for minimum lightship / CAPEX - “steel is cheap and air is free”!

Often premature freeze, influence previous designs, production processes, constraints, etc.

Hull: generation / simulation ► CFD evaluation ► optimisation & feedbackSignificant influence on resistance hence the selection / efficiency of the overall propulsion system

Naked and appended hull / abovewater forms - principal particulars, draughts / trims – lightship / dwt CoGs

Bow - form: full load to ballast, realistic sea states not just ‘clean-calm’ trial – add resistance / seakeeping

Stern - configuration: cognisance prime movers, accommodate efficient propulsors, maximise immersion

- form: optimal flow into propulsors, minimise resistance, good manoeuvrability / seakeeping

Propulsor(s): selection / generation ► CFD evaluation ► optimisation and feedbackSelection, design / optimisation, alignment propulsors and associated appendages, augmentation (ESDs)

In-service / retrofitting: CFD evaluation ► prediction / selection and optimisationPerformance Monitoring / Enhancing Efficiency – hull attributes, ESDs, appendages and / with propulsors



Back to you Edwin

That’s

all

folks!



… well, from me

for now anyway

until the Q&A

Documents

CFD’s role in improving your ship’s energy efficiency