Coupled MPS-modal superposition method for 2D nonlinear fluid-structure interaction problems with free surface

Abstract

Keywords:Moving particle semi-implicit (MPS) method Fluid structure interaction (FSI) Modal superposition Free surface flow Floating beam Flexible wedge dropping a b s t r a c tIn this paper, a coupled MPS-modal superposition method is developed for 2D nonlinear fluid-structure interaction problems. In this method, the rigid-body and relatively small elastic deformation are coupled together, which considers the mutual effect between them. The elastic deformation of the structure is represented by a mode superposition formulation, which is more efficient compared with FEM, regardless of the size of the structure. For 2D cases, if the first three modes are chosen to represent the flexible deformation of the structure, it only results in a 6 Â 6 matrix equation to be solved. For the fluid motion, the modified Moving Particle Semi-implicit (MPS) method, which significantly reduces the fluctuation of pressure calculation of the original MPS method, is used.Two nonlinear problems, i.e. breaking-water-dam impacting a floating beam and flexible wedge slamming into the water are simulated to demonstrate the performance of the developed method. The numerical simulations show that this coupling model is capable of providing stable results that are generally in good agreement with the available experimental data. For the highly nonlinear case with very large rigid motions, the mutual effect between elastic deformation and rigid motions could accumulate to a relatively remarkable level shown by the curves of trajectories or acceleration history of the body mass centre. This also indicates the importance of mutual effect to analyse highly nonlinear FSI problems with large rigid-body motions and relatively small flexible deformation.

The weak coupling between MPS and BEM for wave structure interaction simulation

“…The modified MPS method developed by the authors (Sun et al, 2016(Sun et al, , 2015 is used in this study. A brief illustration is given below.…”

“…More detailed discussion about meshless methods could be found in Liu, 2002, 2007;Zhang et al, 2003). As one of the representative particle method, the Moving Particle Semi-implicit (MPS) Method has been successfully applied to many violent free surface problems (Koshizuka and Oka, 1996;Sun et al, 2016Sun et al, , 2015Xing, 2016). However, one of the problems of the particle methods is the high computational cost.…”

“…The particle method SPH has also been used to calculate the post-breaking waves incorporated with Boussinesq method (Kassiotis et al, 2011). The weak coupling strategy was investigated in this study using modified MPS (proposed by (Sun et al, 2015(Sun et al, , 2016) and BEM.…”

Mixed discrete least squares meshless method for solving the linear and non-linear propagation problems

“…The MPS method is mainly similar to the SPH method [5], but in MPS method, the partial spatial derivatives are calculated without involving the gradient of a kernel function. This method has been applied to simulate dam break [6], 2D nonlinear uid-structure interaction problems with free surface [7], and multiphase ow [8] problems. Kolahdoozan et al also studied the e ect of turbulence closure methods on the accuracy of MPS method for the viscous free surface ows [9].…”

“…Kolahdoozan et al also studied the e ect of turbulence closure methods on the accuracy of MPS method for the viscous free surface ows [9]. However, it is shown that the kernel function used in the original MPS formula does not ensure continuity of the rst derivatives [7,10]. Therefore, some modi cations to the MPS method are proposed [11,12].…”