ITI GmbH today announced that for the first time a marine application of the interdisciplinary simulation software SimulationX has passed Germanischer Lloyd’s (GL) type approval certification.
The SimulationX software module marine propeller for the calculation of ice impact induced loads on the powertrain was designed and developed by ITI in collaboration with GL in accordance with the specifications laid down by GL, the Finnish-Swedish Maritime Administration and the IACS. The software certification conducted by GL proves the software’s high quality standards and is evidence of ITI’s commitment to safe, reliable and energy efficient ship propulsion systems.
According to the new specifications for ice classes that were elaborated by the Finnish and Swedish Maritime Administration, it is required to evaluate the impact of propeller-ice-torque excitation on the drive shaft. The ship’s operational safety and the material’s durability must be demonstrated under various conditions including artic temperatures and critical scenarios. The specifications in question describe three load cases of shock sequences on the propeller as outlined by GL (GL 2012, I – Part 1 – Chapter 2 – Section 13 – Machinery for Ships with Ice Classes), the Finnish-Swedish Maritime Administration/TransportSafetyAgency (TraFi/31298/03.04.01.00/2010) and the IACS (UR I3 Req.2011). The transient simulation of ice impact scenarios has thus become an integral part for shipbuilders and suppliers marking the departure from traditional steady-state analyses used in the past.
By the help of physically correct simulations, SimulationX users predict vibration loads originating from ice impact on the propeller. These extreme conditions are analyzed with SimulationX on a virtual basis over a longer period of time and for various parameter configurations. The simulation results permit reliable evaluations of each component and thus contribute to ensuring safe operation also under arctic conditions. The SimulationX propeller model allows for accurate calculations of torsional vibrations with respect to propeller-ice interactions and the torque loads acting on the powertrain as a consequence of ice impact based on the Baltic and polar ice class definitions. These definitions cover the following ice classes: E1, E2, E3, E4 (GL), IC, IB, IA, IA super (Finnish Marine Administration/TraFi) and PC1, PC2, PC3, PC4, PC5, PC6. PC7 (IACS UR I3, GL).
The model marine propeller was designed for transient and steady-state torsional vibration analyses (TVA) of ship propulsion systems in SimulationX. Both types of calculation can be performed with the same model in one software program. The simulation accounts for propeller inertia, blade excitation as well as various load and damping scenarios. Based on a range of different ice impact scenarios, it is also possible to model ice impact torque on the propeller blades. The propeller is attached to rotatory powertrain models including the conversion of drive torque into flow force and thus into motion. The model can be used for calculations in the time and frequency domains. It is compatible with the simulation software SimulationX. That makes it possible to integrate further model elements, such as shafts, couplings, drive systems and loads, for more advanced torsional vibration analyses. Moreover, SimulationX comes with a broad range of options for visualizing, analyzing and documenting results.