The BMWi-sponsored project HyMOTT-MOTiON deals with the development and application of simulation tools for the hydrodynamic analysis and optimization of offshore vessels for the transport and installation of offshore structures. The vessels feature compact propulsion and manoeuvring devices which show intense interaction with the hull. This essentially limits the operation conditions for various scenarios and concerns especially the dynamic positioning capabilities in challenging environmental and operational conditions, enforces additional resistance and increases vibrations and noise which bother the crew and lead to wear of the vessels components.
For this purpose methods should be developed and combined for practical application.
The existing method for viscous simulations will be further developed: FreSCowill be used for this purpose, which is an in-house CFD-code for viscous calculations based on Reynolds-averaged Navier-Stokes (RANS) equations.
The research areas of this project include:
Efficiency Optimization of the Overset Approach
To enable the planned complex simulations, the overset algorithm has to be optimized to be efficiently used on massive parallel high performance computing systems.
Increasing the Flexibility, Robustness and Accuracy of Overset Simulations
The implicit grid coupling by a non-conservative interpolation provokes mass imbalances along the grid interfaces which leads to spurious pressure defects. This shall be analysed and countermeasures are to be developed.
The overset algorithm shall be improved regarding the geometry intersection. The aim is to be able to simulate the approach of multiple bodies and their intersection.
Development of Fender and Rope Models
To simulate multi-body interaction, fender and rope models shall be developed to couple multiple bodies. This technique can be used to simulate tethered escorts or boatlanding operations.
Simplified Thruster Models
When simulating complex manoeuvres one is confronted with significant time scale differences of the vessel and the rotating propeller. Efficient simulations therefore require an approach to simplify the propeller properties in bollard pull conditions.