An overview of a real-time simulation run conducted with trainee pilots


Pressure distribution on a scaled KVLCC2 hull sailing next to a vertical wall


Calculation of ship-ship and ship-port structure interaction using CFD


Carrying out fast and reliable calculations of hydrodynamic interaction forces


is a vital part of MARIN’s work. A recent project highlights this. Karan Bhawsinka & Serge Toxopeus, k.bhawsinka@marin.nl


A very important effect on vessels moving in ports or confined waters is ship-ship and ship-port structure interaction. It is important to account for these interaction effects in nautical training programmes and in engi- neering analysis because interaction forces can be large and dynamic in nature. These effects can change abruptly and lead to a ship unexpectedly deviating from its original course and consequently, they can influence the nautical accessibility inside ports, access channels and locks.


In a nautical training programme, a crew must learn to anticipate and react to these forces. Additionally, interaction effects should be minimised during the design stage of a new port/lock using engineering analysis. MARIN is working on both fronts. A lot of work has been done into computing these effects both in real time (for nautical training) and fast


16 report


time (for off-line engineering analysis). For real time calculations, MARIN frequently uses DELPASS, a double body potential flow model. MARIN has used DELPASS for assess- ing the nautical accessibility of Rotterdam’s Maasvlakte 2 and the new lock in IJmuiden by coupling it with the full mission bridge simulator. Currently, MARIN is developing an overtaking manoeuvre training programme for young pilots, by coupling DELPASS with its real-time simulator. Interaction forces during an overtaking maneuver can lead to collision, as we can see from the image.


For off-line calculations of interaction effects, MARIN is using its viscous flow CFD Code ReFRESCO. Under phase 1 of the project ‘Natte Kunstwerken van de Toekomst’, MARIN is trying to calculate bank suction forces using this code. MARIN is investigat- ing ReFRESCO’s capability to account for the


effect of propeller rpm, keel clearance and distance to the bank on bank suction forces. The image shows the pressure distribution on a scaled KVLCC2 hull sailing next to a verti- cal wall. These results will be soon validated by using model test data. In phase 2 of this project, MARIN plans to calculate interaction forces on a ship entering a lock. In the long- term ReFRESCO will probably be used for off-line engineering analysis for projects where viscous interaction forces are impor- tant. MARIN also wants to be able to tune DELPASS based on ReFRESCO results for complicated real-time simulation projects.


In the end, all this work will lead to a sophisticated, reliable and fast computation procedure for calculating hydrodynamic in- teraction forces taking into account realistic harbour geometries, viscous effects, free sur- face effects and propeller bank interaction.


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