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Concept Verification & Optimization WP6 - Preliminary Model Test Results. Hans Cozijn - MARIN. Presentation Outline. Conclusions (short) Scale Models and Instrumentation Test Set-up Test Scope Model Test Results DIFIS System Alone (operational / survival)
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Concept Verification & OptimizationWP6 - Preliminary Model Test Results Hans Cozijn - MARIN
Presentation Outline • Conclusions (short) • Scale Models and Instrumentation • Test Set-up • Test Scope • Model Test Results • DIFIS System Alone (operational / survival) • DIFIS System and DP Shuttle Tanker (operational) • Conclusions and Recommendations
Conclusions (short) • Concept appears to be feasible • No un-expected or instable behaviour observed • Limited motions of Buffer Bell(even in survival conditions) • Load variations in the Dome mooring linesare larger than expected • Dome shape is hardly affected by current • DP Shuttle Tanker does not affect DIFIS system
Scale Models • Scale 1:60 • Dome with mooring lines • Riser tube • Buffer bell • DP Shuttle tanker with Offloading Hose
Applied Instrumentation • Motions (contactless optical system) • Accelerations (piezo-type, 3 components) • Line tensions (strain gauge transducers) • Current velocity (EMS) • Wave height (resistance wire) • Wind Velocity (propeller type anemometer) • Video recordings (above / under water) • Photographs (above / under water)
Test Scope (1) • DIFIS System Alone • Current Only conditions (4) • Operational environments (4) • Survival environments (4) • Buffer Bell (1,000 / 2,000 t) • Total 24 tests • 3 additional current only tests(1,000 t Buffer Bell only)
Test Scope (2) • Offloading tests • Operational environments (4) • Buffer Bell (1,000 t) • Shuttle Ballast / Loaded • Total 8 tests
Model Test Results - DIFIS System Alone • Plotted time traces / statistical analysis • Buffer bell displacements • Riser tube axial loads • Mooring line tensions • Contour plots showing system motions • Motion RAOs • Photographs, video recordings
Model Test Results - DIFIS System Alone = Results of the Motion Decay Tests = Test No. 901009 - 1,000t Buffer Bell, Surge Decay
Model Test Results - DIFIS System Alone = Results of the Motion Decay Tests = Test No. 902015 - 2,000t Buffer Bell, Heave Decay
Model Test Results - DIFIS System Alone = Results of the Motion Decay Tests =
Model Test Results - DIFIS System Alone = Results of Tests in Current=
Model Test Results - DIFIS System Alone UR ~ 20 (1,000 t) UR ~ 12 (2,000 t) = Results of Tests in Current (no waves) =
Model Test Results - DIFIS System Alone = Results of Tests in Current (no waves) =
Model Test Results - DIFIS System Alone Test No. 905002 - Survival 3 Conditions (1,000 t) Test No. 907008 - Operational 1 Conditions (2,000 t) = Example Top-view XY Contour Plots =
Model Test Results - DIFIS System Alone Test No. 905002 - Survival 3 Conditions (1,000 t) Test No. 907008 - Operational 1 Conditions (2,000 t) = Example Side-view XZ Contour Plots =
Model Test Results - DIFIS System Alone Test No. 905002 - Survival 3 Conditions (1,000 t) Test No. 907008 - Operational 1 Conditions (2,000 t) = Example Front-view YZ Contour Plots =
Model Test Results - DP Shuttle + DIFIS System • Plotted time traces / statistical analysis • Buffer bell displacements • Riser tube axial loads • Mooring line tensions • Shuttle tanker motions • Export riser loads • Contour plots showing system motions • Motion RAOs • Photographs, video recordings
Model Test Results - DP Shuttle + DIFIS System Test No. 809005 Operational 3 Conditions Loaded Shuttle Tanker Buffer Bell 1,000 t = Example Top-view XY Contour Plots =
Conclusions and Recommendations • Overall behaviour of DIFIS system meets expectations • No unexpected or instable behaviour observed • Dome shape remains intact in current • Variations in Dome mooring line loads (in waves)need to be addressed in the final design • Presence of DP Shuttle Tanker during offloadingdoes not affect the Buffer Bell / Riser Tube • Extrapolation of results to 4,000 m water depth