cfd’s role in improving your ship’s energy efficiency
TRANSCRIPT
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
© Wärtsilä 28-9-2021 The role of CFD in improving vessel energy efficiency / Iulia Oprea3
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
© Wärtsilä 28-9-2021 The role of CFD in improving vessel energy efficiency / Iulia Oprea4
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)
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© Wärtsilä 28-9-2021 The role of CFD in improving vessel energy efficiency / Iulia Oprea5
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%.
© Wärtsilä 28-9-2021 The role of CFD in improving vessel energy efficiency / Iulia Oprea6
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.
© Wärtsilä 28-9-2021 The role of CFD in improving vessel energy efficiency / Iulia Oprea7
RESISTANCE OPTIMISATION
1. Geometrical components
• Hull, appendices and rudder
2. Flow improvement
• Wake field, wave patterns and
streamlines
3. Performance
• Resistance reduction
© Wärtsilä 28-9-2021 The role of CFD in improving vessel energy efficiency / Iulia Oprea8
OPTIMISATION EXAMPLE
• Hull lines improvement (ship design input) for resistance and wake field, bulk carrier example:
Optimised
Optimised
13% resistance
decrease
at 13 knots
© Wärtsilä 28-9-2021 The role of CFD in improving vessel energy efficiency / Iulia Oprea9
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
© Wärtsilä 28-9-2021 The role of CFD in improving vessel energy efficiency / Iulia Oprea10
OPTIMISATION EXAMPLES
• Open propellers• Propeller clearance
• Rudder connection
• Shaft line alignment
• Propeller design
• Nozzle propellers• Nozzle shape
• Nozzle connections
• Rudder connection
• Shaft line alignment
• Propeller design
• Thrusters• Unit position
• Connections/headbox
• OPTI DP (Dynamic Positioning)
• Propeller design
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
© Wärtsilä 28-9-2021 The role of CFD in improving vessel energy efficiency / Iulia Oprea11
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
FRIENDSHIP SYSTEMS © 2021
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
FRIENDSHIP SYSTEMS © 2021
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
FRIENDSHIP SYSTEMS © 2021
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
FRIENDSHIP SYSTEMS © 2021
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
FRIENDSHIP SYSTEMS © 2021
CAESES® | A Simulation-Driven Design Platform
6
FRIENDSHIP SYSTEMS © 2021
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
FRIENDSHIP SYSTEMS © 2021
Mattia Brenner
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 - 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. 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
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
Synthesis (MODM)
Evolution Selection (MADM)
2. Ship design - criteria and approach
4
Strategic model
for ship design
‘Design Spiral’
(IL Buxton 1971)
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
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
5CFD - 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
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
6CFD - 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
Back to you Edwin
That’s
all
folks!
7CFD - 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
… well, from me
for now anyway
until the Q&A