Application of CFD and FEA coupling to predict dynamic behaviour of a flexible barge in regular head waves

Abstract

The ever increasing size of ships and offshore platforms has resulted in 'softer' hull which require hydroelastic effects to be taken into account when predicting fluid-structure interactions. The majority of such investigations are carried out numerically using potential flow solvers. Although nonlinear potential flow methods are also used, RANS/CFD (Reynolds-averaged Navier-Stokes equations) can fully take into account of nonlinearities. It is important, therefore, to verify and validate the results from such numerical predictions. This paper aims to investigate the symmetric motions and responses of flexible barge in regular waves by coupling RANS/CFD and Finite Element software. The two-way interaction between a fluid solver, Star-CCM+, and a structural solver, Abaqus, is applied by exchanging pressures and nodal displacements more than once every time step, namely implicit coupling scheme. A combination of overset and mesh morphing approaches and finite volume solution to allow for the motions of a body at the free surface is used. The computational results compared with experimental measurements and 2-D linear hydroelastic predictions show good agreement. The discrepancies between the 2-D and CFD/FEA cosimulation arise due to the strong influence of bow and stern radiated waves and the agreement between them improves when the nonlinearities are not as dominant.

Numerical investigation into combined global and local hydroelastic response in a large container ship based on two-way coupled CFD and FEA

“…This is because of that the mesh movement between each coupling time step was too large for the present morphing solver to handle it. This problem in the morphing solver has been also pointed recently, by Lakshmynarayanana and Temarel [19]. On the other hand, it can be assumed that the effect of discrepancy in the RBM on elastic deformation would be small, as found from the one-way coupled results described earlier, if the external pressure is properly calculated using deformed ship in the CFD phases.…”

“…A noteworthy work has been recently presented in Ref. [19] to overcome this problem, by employing 'overset' grid technique to the CFD model. Figure 9 illustrates the decomposition method schematically.…”

“…The outlet boundary condition, i.e., the pressure is set to the hydrostatic pressure of the wave to prevent backflow, is used for the downstream plane boundary of the aft end (X = 0). Regarding the other five boundary planes, the velocity-inlet (Inlet) boundary condition, where the velocity of the wave is prescribed to avoid gradient generated from the wall and flow, is adopted [19]. The Euler Overlay Method (EOM) [20,21] is applied to the CFD solution to reduce the effects from the reflection of surface waves from the boundaries or the free surface disturbance due to the ship motion.…”

Analisa Kekuatan Deck BARGE NANIA 10070 DWT Dengan Dua Metode Pembebanan

“…Beberapa jurnal hanya membahas tentang stabilitas dan kekuatan dari tongkang, salah satunya pada tongkang pengangkut limbah batu bara [4]. Pembahasan jurnal lainnya berfokus pada tegangan dan kekuatan struktur dengan pembebanan hidrodinamis [5] [6]. Tongkang diberikan pembebanan batu bara hanya dengan satu gunungan, namun lebih utama mengkaji stabilitas dan ekonomi [7].…”

Efficient FORM-based extreme value prediction of nonlinear ship loads with an application of reduced-order model for coupled CFD and FEA

“…Given the noticeable advances of the computational performance in recent years, the CFD is considered to be one of the promising methods for evaluating them. Up until now, several research efforts have been spent for evaluating hydrodynamic forces under head sea conditions with the CFDs [13,14]. The expansion of the applicability of the CFD towards the whipping evaluations was carried out by integrating the structural model into hydrodynamic calculations [15,16].…”