Numerical Investigations of Waves Interacting with Free Rolling Body by Modified MPS Method

2016 ◽  
Vol 13 (04) ◽  
pp. 1641013 ◽  
Author(s):  
Youlin Zhang ◽  
Zhenyuan Tang ◽  
Decheng Wan
Keyword(s):  
Floating Body ◽  
Roll Motion ◽  
Wave Surface ◽  
Regular Waves ◽  
Mps Method ◽  
Wave Elevation ◽  
Wave Maker ◽  
Numerical Wave ◽  
Moving Particle ◽  
Good Agreement

In this paper, interaction between regular waves and free roll motion of a two-dimensional (2D) floating body is investigated by our in-house meshless particle solver MLParticle-SJTU based on modified moving particle semi-implicit (MPS) method. Numerical wave tank (NWT) is developed to calculate the interaction between waves and floating body, including wave-maker module and free roll motion module. The comparison between the numerical wave elevation and analytical solution shows that the MLParticle-SJTU solver can provide acceptable accuracy of wave making. Roll motion and force acting on the floating body in waves are in good agreement with experimental results. Profiles of the wave surface surrounding floating body are presented.

Solving 2-D Slamming Problems by the Higher-Order MPS Method With an Improved Pressure Gradient Model

2019 ◽  
Author(s):  
Ruosi Zha ◽  
Heather Peng ◽  
Wei Qiu
Keyword(s):  
Pressure Gradient ◽  
Kernel Function ◽  
Particle Interaction ◽  
Interaction Model ◽  
Water Entry ◽  
Higher Order ◽  
Mps Method ◽  
First Order ◽  
Moving Particle ◽  
Good Agreement

Abstract A higher-order moving particle semi-implicit (MPS) method was developed to solve water entry problems. The Wendland kernel function was applied in the particle interaction model. Various models for pressure gradient were investigated. To overcome the inconsistency in the original MPS methods, a pressure gradient correction was implemented to guarantee the first-order consistency of gradient. The corrective matrix was modified by using the derivative of the kernel function. A particle shifting technique was also applied to improve the numerical stability. Validation studies were carried out for water entry of a rigid wedge with the tilting angles of 0°, 10° and 20°, and a rigid ship section. The solutions by the present method are generally in good agreement with experimental data and other published numerical results.

Study on Collision Forces on Water-Front Facilities Induced by Floating Vessels Washed Onto Apron by Tsunami

2010 ◽  
Author(s):  
Koichi Masuda ◽  
Mitsuhiro Masuda ◽  
Tomoki Ikoma
Keyword(s):  
Numerical Simulation ◽  
Floating Body ◽  
Present Calculation ◽  
Floating Bodies ◽  
Floating Structures ◽  
Mps Method ◽  
Calculation Results ◽  
Moving Particle ◽  
Collision Force ◽  
Water Front

The present paper describes the application of the moving particle semi-implicit method to a prediction of collision forces on water-front facilities induced by floating vessels washed onto the apron by tsunami. Effectiveness of the application is verified. Solitary waves are applied to simulated tsunamis in numerical simulation and to the model experiments. A pontoon type floating body is applied to floating structures in numerical simulations using the MPS method. The present calculation results are compared with the experimental results and the applicability of MPS method is discussed. Further, after being washed onto the wharf by tsunami, the characteristics of collision force on water-front facilities induced by the floating bodies are discussed.

Development of the Inflow Boundary With a Free Surface to Apply the MPS Method to Tsunami Analysis on Coastal Areas

2012 ◽  
Author(s):  
Koichi Masuda ◽  
Tomoki Ikoma ◽  
Yasuhiro Aida ◽  
Junpei Takayama
Keyword(s):  
Free Surface ◽  
Fluid Velocity ◽  
Fluid Pressure ◽  
Particle Method ◽  
Wave Form ◽  
Mps Method ◽  
Wave Elevation ◽  
Wave Maker ◽  
Computationally Expensive ◽  
Run Up

The wave maker of MPS method, a kind of particle method, with free surface is developed in this study. This wave maker has the function of the inflow and outflow of particles. Compared to piston-type wave maker, this is possible to reduce the particle for calculation keeping wave form. As a result, this way is faster computation than that. This way controlled by fluid velocity and wave elevation is able to input propagating tsunami of actual phenomenon and data generated by the other result of MPS method and able to continue simulation. This means that it is possible to simulate in detail with 3D-MPS method after 2D-MPS method that is less computationally expensive. This approach is applied to the analysis to tsunami in coastal area. In this study, fluid pressure of run-up-tsunami affecting a building with MPS method is compared and with experiment. And applying MPS method to analysis of run-up-tsunami is considered.

Numerical Simulation on Motion Responses of the Tsunami-Induced Grounding on a Wharf of Floating Structures Using the MPS Method

2008 ◽  
Author(s):  
Koichi Masuda ◽  
Tomoki Ikoma ◽  
Mitsuhiro Masuda ◽  
Yuta Suzuki
Keyword(s):  
Numerical Simulation ◽  
Solitary Wave ◽  
Numerical Simulations ◽  
Experimental Results ◽  
Floating Body ◽  
Floating Structures ◽  
Mps Method ◽  
Model Experiments ◽  
Motion Responses ◽  
Moving Particle

The present paper describes the application of the moving particle semi-implicit method to a prediction of tsunami-induced grounding of floating structures in the vicinity of wharfs. Effectiveness of the application is verified. Solitary wave have been applied to simulated tsunamis in numerical simulation and to the model experiments. A pontoon type floating body has been used to floating structures in numerical simulations using the MPS method. The present numerical results have been compared with the experimental results and the applicability of MPS method has been discussed. Further, after the grounding, the characteristics of gliding distance of floating body on the wharf have been discussed.

Solving 2-D Slamming Problems by an Improved Higher-Order Moving Particle Semi-Implicit Method

2020 ◽  
pp. 1-29
Author(s):  
Ruosi Zha ◽  
Heather Peng ◽  
Wei Qiu
Keyword(s):  
Numerical Solutions ◽  
Domain Size ◽  
Water Entry ◽  
Higher Order ◽  
Time Step ◽  
Index Method ◽  
Mps Method ◽  
Particle Spacing ◽  
Moving Particle ◽  
Good Agreement

A higher-order moving particle semi-implicit (MPS) method was further developed to solve 2-D water entry problems. To overcome the inconsistency in the original MPS methods, a pressure gradient correction was implemented to guarantee the first-order consistency of the gradient. The corrective matrix was modified by using the derivative of the kernel function. A particle shifting technique was also applied to improve the numerical stability. Validation studies were carried out for water entry of a rigid wedge with the tilting angles of 0º, 10°, and 20º, and two rigid ship sections. Convergence studies were conducted on domain size, particle spacing, and time step. A particle convergence index method was proposed to evaluate numerical uncertainties in the improved MPS method. Uncertainties in numerical solutions due to spatial discretization were calculated. The predicted impact pressures and forces by the present method are in good agreement with experimental data.

Study on Drifting Distance and Collision Force of Floating Vessels Run on Apron by Tsunami

2009 ◽  
Author(s):  
Koichi Masuda ◽  
Takujiro Miyamoto ◽  
Tomoki Ikoma ◽  
Mitsuhiro Masuda
Keyword(s):  
Numerical Simulation ◽  
Solitary Wave ◽  
Numerical Simulations ◽  
Experimental Results ◽  
Floating Body ◽  
Floating Structures ◽  
Mps Method ◽  
Model Experiments ◽  
Moving Particle ◽  
Collision Force

The present paper describes the application of the moving particle semi-implicit method to a prediction of drifting distance and collision force of floating vessels run on wharf by tsunami. Effectiveness of the application is verified. Solitary wave have been applied to simulated tsunamis in numerical simulation and to the model experiments. A pontoon type floating body has been used to floating structures in numerical simulations using the MPS method. The present numerical results have been compared with the experimental results and the applicability of MPS method has been discussed. Further, after the running on wharf by tsunami, the characteristics of drifting distance and collision force of floating body on the wharf have been discussed.

Solving 2-D Slamming Problems by the MPS Method With Source Term Correction

2018 ◽  
Author(s):  
Ruosi Zha ◽  
Heather Peng ◽  
Wei Qiu
Keyword(s):  
Source Term ◽  
Correction Method ◽  
Water Entry ◽  
Mps Method ◽  
Linear Elastic ◽  
Correction Scheme ◽  
Moving Particle ◽  
Weak Coupling Method ◽  
Elastic Particles ◽  
Good Agreement

An improved moving particle semi-implicit (MPS) method was developed to solve water entry problems. The traditional mixed source term was modified based on a prediction-correction scheme to suppress pressure oscillations. An improved free surface identification method was implemented for fluid computations. A weak coupling method was adopted for fluid-structure interaction. The structures were modeled by isotropic linear elastic particles. The application of the source term correction method leads to a better pressure prediction and therefore a more accurate interaction between the fluid and the structure. Validation studies were carried out for water entry of two rigid wedges, a rigid ship section, and a flexible wedge. The results by the present MPS method are in good agreement with experimental data and other published numerical results.

scholarly journals LNG Tank Sloshing Simulation of Multidegree Motions Based on Modified 3D MPS Method

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Chunhui Wang ◽  
Chunyu Guo ◽  
Fenglei Han
Keyword(s):  
Free Surface ◽  
Weighted Average ◽  
Kernel Functions ◽  
Computational Stability ◽  
Mps Method ◽  
Fluid Sloshing ◽  
Particle Hydrodynamics ◽  
Moving Particle ◽  
Lng Tank ◽  
Stability And Accuracy

Modified 3D Moving Particle Semi-Implicit (MPS) method is used to complete the numerical simulation of the fluid sloshing in LNG tank under multidegree excitation motion, which is compared with the results of experiments and 2D calculations obtained by other scholars to verify the reliability. The cubic spline kernel functions used in Smoothed Particle Hydrodynamics (SPH) method are adopted to reduce the deviation caused by consecutive two times weighted average calculations; the boundary conditions and the determination of free surface particles are modified to improve the computational stability and accuracy of 3D calculation. The tank is under forced multidegree excitation motion to simulate the real conditions of LNG ships, the pressures and the free surfaces at different times are given to verify the accuracy of 3D simulation, and the free surface and the splashed particles can be simulated more exactly.

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