ADAM4EVE workshop on Adaptive Ship Hull Forms Adaptive Stern Geometry Thomas Stoye, Knut Frömming Flensburger Schiffbau-Gesellschaft June 4th, 2015 VTT Technical Research Centre of Finland, Espoo

Table of Contents Motivation & Objectives Evaluation Methods Evaluation Results Demonstrator Statement from class societies Conclusion Source: CALMAC

Motivation Design to specific design-point Operational profile consist of many points Adjustment of hull-form to actual operation point Stern part promising Adaptation physically feasible Source: FSG

Objectives Stern wedge change possible Large impact on resistance Identification of movable part Variation of length and angle within boundaries Change hydrodynamic body Movable duck-tail Source: FSG

Evaluation Methods CFD-study to determine parameters of variable part Viscous flow methods for resistance evaluation Selection of promising parameters Design of steel structure and piping-system Structural evaluation by class-rules and FE-Calculations Further evaluation of performance by model tests Resistance, open-water propeller and self-propulsion tests

Evaluation Results - CFD Variation of length and angle within boundaries Movable duck-tail with fixed angle selected Resistance reduction of up to 3% for some operational points Longer flap for larger speed Shorter flap for slower speed Flap Length [cm] Flap Angle [°] 80 7 14 20 30 40

Evaluation Results – Model Tests Source: ADAM4EVE-WP10 - VTT Verification of CFD-Results for resistance by model tests Additionally open-water propeller and self-propulsion tests Savings for large draft and high speed up to 7% of PD Fuel Savings for machinery arrangement and given operational profile ~3-3.5% per year Larger Benefit when implemented in new design Source: ADAM4EVE-WP06 - FSG

Model tests A new modular ship model, scale 1:16.697, was built for model tests Model propellers from FSG were used. The model scale resistance and propulsion tests were performed for the RoPax ship model with an adaptable stern geometry. 8

Draft in the resistance tests [m] Draft in the propulsion tests [m] Model test program Test program for the resistance and propulsion tests Speed points: The model test speeds: 13, 14, 15, 16, 17, 18.5, 19.5 and 20.5 knots in full scale, (1.637 – 2.581 m/s in model scale). In the CFD computations the selected speed points were 14 and 19.5 knots. Measured quantities: Open water tests of the propellers. Resistance test: towing force, sinkage fore and aft. Propulsion test: towing force, number of revolutions, thrust and torque of the propellers, sinkage fore and aft. The analysis to the full scale was made using ITTC-78 method. Hull version Flap length [m] Flap angle [°] Draft in the resistance tests [m] Draft in the propulsion tests [m] Initial aft (no flap) 0.0 4.8, 4.2 Short flap 0.4 20 4.8 Long flap 0.8 14 17 9

Resistance tests results T=4.8m Opimum flalp angle depending on speed max. Flap angle is never the best => optimum within measured range 10

Propulsion test results T=4.8m Propulsion optima are not always euqal to resistance optima: => Pressure field of propeller influences trim/draught of ship 11

Resistance tests results T=4.2m A significant influence of the draught on the working principle of the flap can be seen => Adaptable system useful 12

Propulsion test results T=4.2m 13

Evaluation Results – Structure Steel structure designed in 3D Class-Rules as basis for design Slamming loads determined by CFD FE-model used for direct calculations Critical areas identified – No show-stoppers Steel structure to be improved in next stage

Demonstrator Visualization of principle Steel structure with actuator Simplified 1:5 model Production ongoing Source: ADAM4EVE-WP06

Demonstrator Installation of pneumatic actuators Functional test Identification of robust pneumatic system

Class Societies Evaluation No major HAZIDS identified All risks are of controllable extend Details of fixation, dimensioning of piping-system to be looked Control-system and maintenance to be designed more detailed Evaluation for each individual application to be examined Source: ADAM4EVE-WP06 FSG

Conclusion Performance of idea very promising Implementation feasible and realistic Results certain due to model-tests Structural challenges can be solved No major HAZIDS identified To be developed and evaluated for each individual ship

Thank you for your attention! Source: VTT Thank you for your attention! The Project is funded in the Seventh Framework Program of the European Union - Contract No.: SCP2-GA-2012-314206

The Project is funded in the Seventh Framework Programme of the European Union Contract No.: SCP2-GA-2012-314206