Flow Simulation of Jet Deviation by Rotating Pelton Buckets Using Finite Volume Particle Method

2015 ◽  
Vol 137 (7) ◽  
Author(s):  
Christian Vessaz ◽  
Ebrahim Jahanbakhsh ◽  
François Avellan
Keyword(s):  
Finite Volume ◽  
High Speed ◽  
Pressure Field ◽  
Flow Simulation ◽  
Numerical Data ◽  
Particle Method ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Convergence Study ◽  
Good Agreement

The objective of the present paper is to perform numerical simulations of a high-speed water jet impinging on rotating Pelton buckets using the finite volume particle method (FVPM), which combines attractive features of smoothed particle hydrodynamics (SPH) and conventional grid-based finite volume. The particles resolution is first validated by a convergence study. Then, the FVPM results are validated with available measurements and volume of fluid (VOF) simulations. It is shown that the pressure field in the buckets inner wall is in good agreement with the experimental and numerical data and the evolution of the flow pattern matches the high-speed visualization.

Numerical Simulation of High Speed Water Jet Erosion of Sand Bed Based on SPH

2014 ◽  
Vol 641-642 ◽  
pp. 304-308
Author(s):  
Fu Sheng Ni ◽  
De Yi Zhang ◽  
Hui Wang ◽  
Lei Gu
Keyword(s):  
High Speed ◽  
Pressure Field ◽  
Water Jet ◽  
Target Distance ◽  
Sph Method ◽  
Simulation Process ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Jet Velocity ◽  
Key Techniques

Water jet technology is widely used in dredging engineering. Since there will be large deformation of sand bed during erosion by water jet, the calculation mesh will be distorted seriously and lead to simulation failure. In order to solve the problem, the Smoothed Particle Hydrodynamics (SPH) method was used to simulate the dynamic process of high speed water jet erosion of sand bed. The simulation process and key techniques were discussed, the effect of water jet velocity and water jet target distance on the depth of eroded pit was studied. The results show that SPH could describe the process intuitively and the evolution of particle velocity field and sand bed pressure field could be shown clearly. The depth of the pit varies with time linearly. The decrease of water jet target distance and the increase of the water jet velocity deepen the eroded pit.

Smoothed Particle Method for Studying Heat and Mass Transfer Between Fluid and Solid

2014 ◽  
Author(s):  
Zhi-Gang Feng ◽  
Miguel Cortina Ponton
Keyword(s):  
Particle Method ◽  
Boussinesq Approximation ◽  
Sph Method ◽  
Square Enclosure ◽  
Heated Cylinder ◽  
Smoothing Kernel ◽  
Particle Hydrodynamics ◽  
Different Temperatures ◽  
Smoothed Particle ◽  
Good Agreement

Smoothed Particle Hydrodynamics (SPH) is a meshless Lagrangian method in which the domain is represented by particles. Each particle is assigned properties such as mass, pressure, density, temperature, and velocity. These properties are then evaluated at the particle positions using a smoothing kernel that integrates over the values of the surrounding particles. In the present study, the SPH method is first used to study the flow between infinite plates at different temperatures; velocity and temperature profiles are compared to the analytical solution and good agreements are found. Then, the SPH is further extended to study the heat transfer of an isothermal cylinder in a periodic flow. The velocity profile is found to be in good agreement with results provided in the literature, and the temperature field obtained seems reasonable. Finally, the natural convection of a heated cylinder in a square enclosure is studied. For this, the discretized version of the heat equation is used in conjunction with the Boussinesq approximation. The results between the SPH with and without a tensile instability are compared.

scholarly journals Extensions of the meshless Finite Volume Particle Method (FVPM) for static and dynamic free-surface flows

2018 ◽  
Author(s):  
Nathan Quinlan
Keyword(s):  
Free Surface ◽  
Finite Volume ◽  
Pressure Fluctuations ◽  
Particle Method ◽  
Free Surface Flows ◽  
Hydrostatic Equilibrium ◽  
Surface Flows ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Volume Method

The Finite Volume Particle Method (FVPM) is a meshless method that incorporates features of both Smoothed Particle Hydrodynamics and the Finite Volume Method. Here, two new formulations are presented which enhance its performance in simulation of free surface flows. One is a method for determining the velocity of the free surface, making use of a partial Riemann problem to analyse the flow between the particle barycentre and the geometric free surface. The second is a well-balanced formulation for gravity forces that enables hydrostatic equilibrium to be preserved exactly. Results are presented for hydrostatic, 1D impact, dambreak and deep-water standing wave test cases. Computations display convergence and good agreement with experimental data. The new methods recover exact hydrostatic equilibrium, improve robustness and reduce acoustic pressure fluctuations in dambreak flows, and reduce dissipation.

scholarly journals Impact and Fire Modeling Considerations Employing SPH Coupling to a Dilute Spray Fire Code

2009 ◽  
Author(s):  
Alexander L. Brown
Keyword(s):  
High Speed ◽  
Good Method ◽  
Predictive Tool ◽  
Surface Deposition ◽  
Impact Surface ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Model Inadequacy ◽  
The Impact ◽  
Adequate Method

Transportation accidents and the subsequent fire present a concern. Particularly energetic accidents like an aircraft impact or a high speed highway accident can be quite violent. We would like to develop and maintain a capability at Sandia National Laboratories to model these very challenging events. We have identified Smoothed Particle Hydrodynamics (SPH) as a good method to employ for the impact dynamics of the fluid for severe impacts. SPH is capable of modeling viscous and inertial effects for these impacts for short times. We have also identified our fire code Lagrangian/Eulerian (L/E) particle capability as an adequate method for fuel transport and spray modeling. A fire code can also model the subsequent fire for a fuel impact. Surface deposition of the liquid may also be acceptably predicted with the same code. These two methods (SPH and L/E) typically employ complimentary length and timescales for the calculation, and are potentially suited for coupling given adequate attention to relevant details. Length and timescale interactions are important considerations when joining the two capabilities. Additionally, there are physical model inadequacy considerations that contribute to the accuracy of the methodology. These models and methods are presented and evaluated. Some of these concerns are detailed for a verification type scenario used to show the work in progress of this coupling capability. The importance of validation methods and their appropriate application to the genesis of this class of predictive tool are also discussed.

GIS Enabled SPH-Soil Modeling for the Post-Failure Flow of Landslides Under Seismic Loadings

2018 ◽  
Vol 15 (06) ◽  
pp. 1850046 ◽  
Author(s):  
Man Hu ◽  
Qiuqiang Liu ◽  
Fei Wu ◽  
Mengting Yu ◽  
Shenghua Jiang
Keyword(s):  
Plastic Behavior ◽  
Irregular Boundary ◽  
Landslide Modeling ◽  
Linear Elastic ◽  
Soil Model ◽  
Particle Hydrodynamics ◽  
Sph Model ◽  
Seismic Loadings ◽  
Smoothed Particle ◽  
Good Agreement

Landslide can usually be induced by a strong earthquake, and it causes very serious property damage and human casualties. Modeling of post-failure flow of landslides is one of the important approaches that can be used to simulate landslide flow developments and predict the landslide hazard zone. In this paper, a Smoothed Particle Hydrodynamics (SPH) model based on the constitution of elastic-plastic constitutive mechanics for soil has been developed for simulating the behavior of a class of geo-materials under the seismic loadings. Our SPH-Soil model considers the plastic behavior of the materials, and hence it is very important for more accurate and realistic simulations of geo-materials of soil type. The implemented materials laws in the SPH-Soil code include classical elastic-plasticity with a linear elastic part, and different applicable yield surfaces with nonassociated flow rules. In order to apply this model to actual landslide modeling the Geographic Information System (GIS) is utilized to generate site-specific models. We have thus developed a C# code to generate the particles of a given landslide site, which produces realistic particle mass and actual complicated boundaries for the SPH-Soil model. With GIS enabled, complex topography and irregular boundary can be accurately and easily built up. Then the SPH-Soil code has been applied to the well-known Daguangbao landslide, which was triggered by Wenchuan earthquake in 2008. The topographies after failure were compared with that obtained from field collected data and good agreement was found.

Numerical Simulation of Scouring in Overtopping Dam-break Flow

2021 ◽  
Author(s):  
Can Huang ◽  
Xiaoliang Wang ◽  
Qingquan Liu
Keyword(s):  
Numerical Simulation ◽  
Empirical Relationship ◽  
Dam Break ◽  
Experimental Conditions ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Dam Break Flow ◽  
Scouring Process ◽  
Overtopping Erosion ◽  
Good Agreement

<p>Overtopping dam-break flow has great harm to the earthen embankments due to the hydraulic erosion. Some researchers have carried out relevant model experiments, but it is difficult to achieve the experimental conditions for the actual situation. The common numerical simulation is to express the scouring process through the empirical relationship, which obviously could not reflect the real scouring process. In this paper, a new overtopping erosion model using Smoothed Particle Hydrodynamics (SPH) is proposed. When the shear stress on the sediment SPH particle exceeds the critical stress, the erosion process begins. Then, when a sediment SPH particle is completely eroded, it will begin to move and is described as a non-Newtonian fluid. The un-incipient sediment particles are treated as boundary. This model is well validated with plane dike-breach experiment, and has also achieved a good agreement with erodible bed dam-break experiment.</p>

An Algorithm for Fluid–Solid Coupling Based on SPH Method and Its Preliminary Verification

2018 ◽  
Vol 16 (02) ◽  
pp. 1846008
Author(s):  
X. J. Ma ◽  
M. Geni ◽  
A. F. Jin
Keyword(s):  
Elastic Solid ◽  
Free Surface Flow ◽  
Surface Flow ◽  
Sph Method ◽  
Particle Hydrodynamics ◽  
Sph Model ◽  
Smoothed Particle ◽  
Feasible Algorithm ◽  
Coupling Algorithm ◽  
Good Agreement

Based on the fundamental theory of smoothed-particle hydrodynamics (SPH), a feasible algorithm for fluid–solid coupling on interface is applied to describe the dynamic behavior of fluid and solid by utilizing continuum mechanics governing equations. Numerical simulation is conducted based on the proposed SPH model and the fluid–solid interface coupling algorithm, and good agreement is observed with the experiment results. It is shown in the results that the present SPH model is able to effectively and accurately simulate the free-surface flow of fluid, deformation of the elastic solid and the fluid–solid impacting.

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