Stable Moving Particle Semi Implicit Method for Modeling Waves Generated by Submarine Landslides

2014 ◽  
Author(s):  
Mohammad Amin Nabian ◽  
Leila Farhadi
Keyword(s):  
Water Surface ◽  
Surface Profile ◽  
Particle Methods ◽  
Water Tank ◽  
Submarine Landslides ◽  
Fractional Step Method ◽  
Time Step ◽  
Mps Method ◽  
Water Surface Profile ◽  
Moving Particle

A mesh-free numerical formulation, known as Moving Particle Semi Implicit (MPS) Method, is used for modeling waves generated by submarine landslides. In this formulation, approximations are provided to the strong form of PDEs on the basis of integral interpolants. The governing equations, Navier-Stokes equations, are solved in a 2D fully Lagrangian form. This method utilizes a fractional step method and splits each time step in two steps. The fluid is represented with particles and the motion of each particle is calculated through interactions with neighboring particles by means of a kernel function. Landslides in this paper are simulated by a submerged triangle rigid wedge sliding along an inclined plane into a water tank. As the wedge sinks, a wave and a vortex is formed. The water surface profile, velocity field and pressure field are represented at different times. To confirm the accuracy of the model, the water surface profile is compared with the experimental data, showing good agreement. Simulations can continue for a long period of time without any instability occurrence and this is a remarkable competency amongst other particle methods. A discussion on multi-size particle strategy and its ability to increase the efficiency of MPS method is provided at the end of the paper.

Numerical Simulation of Solitary Wave Using the Fully Lagrangian Method of Moving Particle Semi Implicit

2014 ◽  
Author(s):  
Mohammad Amin Nabian ◽  
Leila Farhadi
Keyword(s):  
Numerical Simulation ◽  
Free Surface ◽  
Solitary Wave ◽  
Stokes Equations ◽  
Rock Avalanche ◽  
Water Tank ◽  
Step Method ◽  
Fractional Step Method ◽  
Time Step ◽  
Moving Particle

A mesh-less numerical approach, called the moving particle semi implicit method (MPS), is presented to solve inviscid Navier-Stokes equations in a fully Lagrangian form using a fractional step method. This method consists of splitting each time step in two steps. The fluid is represented with particles and the motion of each particle is calculated through interactions with neighboring particles by means of a kernel function. In this paper, the MPS method is used to simulate a dynamic system consisting of a heavy box sinking vertically into a water tank, known as Scott Russell’s wave generator problem. This problem is an example of a falling rock avalanche into natural or artificial reservoirs. The box sinks into water tank and as a result the water is heaved up to form a solitary wave and a reverse plunging wave which forms a vortex. This vortex follows the solitary wave down the water tank. The good agreement between the numerical simulation and the analytical solution confirms the accuracy of the model. This proves the applicability of the present model in simulating complex free surface problems. The number of particles on free surface is presented as an indicator of stability of the model.

scholarly journals FEM analysis of water surface profile using VOF Method

2021 ◽  
Vol 1116 (1) ◽  
pp. 012112
Author(s):  
Avdhesh Kumar Sharma ◽  
Prashant Kumar Dixit ◽  
Shashank Srivastava
Keyword(s):  
Water Surface ◽  
Surface Profile ◽  
Fem Analysis ◽  
Vof Method ◽  
Water Surface Profile

Optimization of Moving Particle Semi-Implicit (MPS) Method and Studying of Flow Instability

2018 ◽  
Author(s):  
Kailun Guo ◽  
Ronghua Chen ◽  
Suizheng Qiu ◽  
Wenxi Tian ◽  
Guanghui Su ◽  
...  
Keyword(s):  
Multiphase Flows ◽  
Flow Instability ◽  
Free Particle ◽  
Particle Method ◽  
Severe Accident ◽  
Particle Methods ◽  
Two Phase ◽  
Mps Method ◽  
Viscosity Term ◽  
Moving Particle

Multiphase flow widely exists in the nature and engineering. The two-phase flow is the highlight of the studies about the flow in the vessel and steam explosion in nuclear severe accidents. The Moving Particle Semi-implicit (MPS) method is a fully-Lagrangian particle method without grid mesh which focuses on tracking the single particle and concerns with its movement. It has advantages in tracking complex multiphase flows compared with gird methods, and thus shows great potential in predicting multiphase flows. The objective of this thesis is to develop a general multiphase particle method based on the original MPS method and thus this work is of great significance for improving the numerical method for simulating the instability in reactor severe accident and two-phase flows in vessel. This research is intended to provide a study of the instability based on the MPS method. Latest achievements of mesh-free particle methods in instability are researched and a new multiphase MPS method, which is based on the original one, for simulating instability has been developed and validated. Based on referring to other researchers’ papers, the Pressure Poisson Equation (PPE), the viscosity term, the free surface particle determination part and the surface tension model are optimized or added. The numerical simulation on stratification behavior of two immiscible flows is carried out and results are analyzed after data processing. It is proved that the improved MPS method is more accurate than the original method in analysis of multiphase flows. In this paper, the main purposes are simulating and discussing Rayleigh-Taylor (R-T) instability and Kelvin-Helmholtz (K-H) instability. R-T and K-H instability play an important role in the mixing process of many layered flows. R-T instability occurs when a lower density fluid is supported by another density higher fluid or higher density fluid is accelerated by lower density fluid, and the resulting small perturbation increases and eventually forms turbulence. K-H instability is a small disturbance for two different densities, such as waves, at the interface of the two-phase fluid after giving a fixed acceleration in the fluid. Turbulence generated by R-T instability and K-H instability has an important effect in applications such as astrophysics, geophysics, and nuclear science.

Effects of Wall Condition of a Plunging Body on Splash

2011 ◽  
Author(s):  
Masao Yokoyama ◽  
Yoshihiro Kubota ◽  
Osamu Mochizuki
Keyword(s):  
Numerical Simulation ◽  
Implicit Method ◽  
Water Tank ◽  
Air Cavity ◽  
Slip Ratio ◽  
Mps Method ◽  
Swelling Degree ◽  
Living Things ◽  
Wall Condition ◽  
Moving Particle

Splashes generated by hydrogel sphere were simulated numerically and experimentally for investigating the effects of slip like mucus of living things. Numerical simulation using MPS (Moving Particle Semi-implicit) method was carried out. We defined the slip ratio as the swelling degree of hydrogel and installed the slip ratio into the MPS method. The swelling degree is the ratio of the weight of water against that of hydrogel. We simulated the splashes generated by the hydrogel spheres which had the different swelling degree plunging into water. As the evaluation of swelling degree on the surface of actual hydrogel spheres we also tested by using the hydrogel spheres plunging into water experimentally. The height of splash as a result of reaction of the air cavity became higher according to the increase of the swelling degree. The speed of hydrogel sphere sinking in water tank was also quicker in the numerical simulation. The reason of these results was that the velocity of water around the hydrogel sphere became quicker due to the slip on the surface.

Sign in / Sign up

Export Citation Format

Share Document