Session: 02-04-02 Extreme Loads and Response 2

Submission Number: 178469

An Approach to Simulate Ship Motion and Structural Response With Fully Coupled CFD-FEA Analysis Using 3-Dimensional Numerical Water Tank Under ICFD Methodology 

In the present study, in order to investigate applicability of state of the art numerical technology a series of ship motion simulation is carried in regular and irregular waves. A new approach to simulate fluid structure interaction (FSI) of a ship in three dimensional numerical water tank using ICFD (Incompressible computational fluid dynamics) methodology is utilized. ICFD is the state of the art methodology to simulate both structure and incompressible fluid using finite element method (FEM) where both are modeled with Lagrange mesh with relatively rapid computation time.

 Validation of ICFD methodology is shortly introduced using sphere slamming as well as bow flare slamming, where numerical results are compared with experimental results.

As a case study, a series of numerical simulation of ships in regular waves is demonstrated. As a preliminary study, an 8000TEU container ship is adopted and effect of hull girder rigidity is investigated by comparing two cases. In one case, the ship is modeled elastic-plastic, and in the other case, the ship is modeled as rigid. Vibration of hull girder in case of elastic model, difference of vertical acceleration and velocity of bow bottom, which is related to bow flare slamming, is compared and discussed in detail.

As a preliminary study, it can be said that ICFD gives fairly reasonable results for ship motion and structural response including global hull girder deformation and bending stress distribution. Applicability and Robustness of the present FSI method with fully coupled ICFD-FEA analysis is demonstrated.

 Effect of hull girder rigidity on hull girder deformation, vertical acceleration and vertical velocity is clearly identified. In order to accurately evaluate an 8000TEU container ship motion and structural response, it is needed to consider hull girder deformation/vibration, and therefore the need for hydro-elastic analysis with fully coupled analysis is reconfirmed.

Finally ongoing project of simulation of an elastic-plastic container ship in regular waves and in numerical water tank is shortly introduced.

Presenting Author: Yasuhira Yamada National Institue of Maritime, Port and Aviation Technology

Presenting Author Biography: Got PhD at Technical University of Denmark in 2007.
Research Engineer at NMRi, MPAT, which is a governmental research insitute in Japan.
Director of Marrine Accident Analysys Center in NMRI

Authors:

Yasuhira Yamada National Institue of Maritime, Port and Aviation Technology