Hydrodynamic optimization of semi-submersibles for...

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Hydrodynamic optimization of semi-submersibles for better seakeeping performance

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Jan Land

DNV GL - Software

DNV GL © 2014

Sesam CAESES software

ComputerAidedEngineeringSystemEmpoweringSimulation

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The case study uses Sesam CAESES software as a calculation tool for the analysis.

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Offshore industry

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Workflow

Variable Geometry

Pre-processing

Software Connection

Post-processing

Variation & Optimization

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How to optimize a semi-submersible

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Variable geometry

� Fully parametric surface model

� Constant displacement via volume

shifts

� Topology may change (e.g.

disappearing surfaces)

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Variations

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Pre-processing

� Structured PanelMesh used for

discretization

� Parametric refinement for all patches

� Customized export using Sesam’s

FEM-format

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Software connection

� Intuitive set-up using Sesam

CAESES’ SoftwareConnector

� Process chain connects

– Sesam HydroD

– PostResp

� Compute semi-submersible’s worst

relative motion within a given

seastate (air gap)

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Search

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Post-processing

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Variation & optimization

� Design of Experiments

– Sobol algorithm

– 150 variants

� Six free variables

� Constraints

– Keep displacement

– Keep draft

� Objective

– Find design with lowest

relative motion

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Improved design

Improvement

� Reduction of relative motion by about

4% when compared to baseline

� Decrease of wetted surface

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Baseline

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Result

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Contact info

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DNV GL - SoftwareDNV GL is the world-leading provider of software for a safer, smarter and greener future in the energy, process and maritime industries. Our solutions support a variety of business critical activities including design and engineering, risk assessment, asset integrity and optimization, QHSE, and ship management. Our worldwide presence facilitates a strong customer focus and efficient sharing of industry best practice and standards.

For presentation, software demo, training or quote please contact:

Software.communications@dnvgl.com

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SAFER, SMARTER, GREENER

www.dnvgl.com/software

Thank you

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