scholarly journals Progress in the Smoothed Particle Hydrodynamics Method to Simulate and Post-process Numerical Simulations of Annular Airblast Atomizers

2020 ◽  
Vol 105 (4) ◽  
pp. 1119-1147
Author(s):  
G. Chaussonnet ◽  
T. Dauch ◽  
M. Keller ◽  
M. Okraschevski ◽  
C. Ates ◽  
...  
Keyword(s):  
Smoothed Particle Hydrodynamics ◽  
Flux Ratio ◽  
Liquid Sheet ◽  
Sph Method ◽  
Post Process ◽  
Finite Time Lyapunov Exponent ◽  
Fragmentation Spectrum ◽  
Particle Hydrodynamics ◽  
Primary Breakup ◽  
Smoothed Particle

AbstractThis paper illustrates recent progresses in the development of the smoothed particle hydrodynamics (SPH) method to simulate and post-process liquid spray generation. The simulation of a generic annular airblast atomizer is presented, in which a liquid sheet is fragmented by two concentric counter swirling air streams. The accent is put on how the SPH method can bridge the gap between the CAD geometry of a nozzle and its characterization, in terms of spray characteristics and dynamics. In addition, the Lagrangian nature of the SPH method allows to extract additional data to give further insight in the spraying process. First, the sequential breakup events can be tracked from one large liquid blob to very fine stable droplets. This is herein called the tree of fragmentation. From this tree of fragmentation, abstract quantities can be drawn such as the breakup activity and the fragmentation spectrum. Second, the Lagrangian coherent structures in the turbulent flow can be determined easily with the finite-time Lyapunov exponent (FTLE). The extraction of the FTLE is particularly feasible in the SPH framework. Finally, it is pointed out that there is no universal and ultimate non-dimensional number that can characterize airblast primary breakup. Depending on the field of interest, a non-dimensional number (e.g. Weber number) might be more appropriate than another one (e.g. momentum flux ratio) to characterize the regime, and vice versa.

Air-Assisted Atomization at Constant Mass and Momentum Flow Rate: Investigation into the Ambient Pressure Influence With the Smoothed Particle Hydrodynamics Method

2020 ◽  
Vol 142 (3) ◽  
Author(s):  
Geoffroy Chaussonnet ◽  
Shreyas Joshi ◽  
Simon Wachter ◽  
Rainer Koch ◽  
Tobias Jakobs ◽  
...  
Keyword(s):  
Smoothed Particle Hydrodynamics ◽  
High Speed ◽  
Ambient Pressure ◽  
Velocity Ratio ◽  
Flux Ratio ◽  
Mean Velocity ◽  
Air Stream ◽  
Fragmentation Spectrum ◽  
Particle Hydrodynamics ◽  
Smoothed Particle

Abstract A twin-fluid atomizer configuration is simulated by means of the two-dimensional (2D) weakly compressible smoothed particle hydrodynamics (SPH) method and compared to experiments. The gas-to-liquid ratio (GLR), the momentum flux ratio, and the velocity ratio are set constant for different ambient pressures, which lead to different gaseous flow sections. The objectives of this study are (i) to investigate the effect of ambient pressure at constant global parameters and (ii) to verify the capability of 2D SPH to qualitatively predict the proper disintegration mechanism and to recover the correct evolution of the spray characteristics. The setup consists of an axial liquid jet of water fragmented by a coflowing high-speed air stream (Ug = 80 m/s) in a pressurized atmosphere up to 16 bar. The results are compared to the experiment and presented in terms of (i) mean velocity profiles, (ii) drop size distributions, and (iii) Sauter mean diameter (SMD) of the spray. It is found that there exists an optimal pressure to minimize the mean size of the spray droplets. Finally, two new quantities related to atomization are presented: (i) the breakup activity that quantifies the number of breakup events per time and volume unit and (ii) the fragmentation spectrum of the whole breakup chain, which characterize the cascade phenomenon in terms of probability. The breakup activity confirms the presence of the optimal pressure, and the fragmentation spectrum gives information on the type of breakup, depending on the ambient pressure.

scholarly journals Numerical Simulation of Non-Homogeneous Viscous Debris-Flows Based on the Smoothed Particle Hydrodynamics (SPH) Method

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2314 ◽  
Author(s):  
Shu Wang ◽  
Anping Shu ◽  
Matteo Rubinato ◽  
Mengyao Wang ◽  
Jiping Qin
Keyword(s):  
Debris Flow ◽  
Water Content ◽  
Smoothed Particle Hydrodynamics ◽  
Debris Flows ◽  
Sph Method ◽  
Particle Hydrodynamics ◽  
Sph Model ◽  
Smoothed Particle ◽  
The Impact ◽  
Kinetic And Potential Energies

Non-homogeneous viscous debris flows are characterized by high density, impact force and destructiveness, and the complexity of the materials they are made of. This has always made these flows challenging to simulate numerically, and to reproduce experimentally debris flow processes. In this study, the formation-movement process of non-homogeneous debris flow under three different soil configurations was simulated numerically by modifying the formulation of collision, friction, and yield stresses for the existing Smoothed Particle Hydrodynamics (SPH) method. The results obtained by applying this modification to the SPH model clearly demonstrated that the configuration where fine and coarse particles are fully mixed, with no specific layering, produces more fluctuations and instability of the debris flow. The kinetic and potential energies of the fluctuating particles calculated for each scenario have been shown to be affected by the water content by focusing on small local areas. Therefore, this study provides a better understanding and new insights regarding intermittent debris flows, and explains the impact of the water content on their formation and movement processes.

scholarly journals Application of Smoothed Particle Hydrodynamics (SPH) for the Simulation of Flow-like Landslides on 3D Terrains

2022 ◽  
Author(s):  
Binghui Cui ◽  
Liaojun Zhang
Keyword(s):  
Risk Assessment ◽  
Smoothed Particle Hydrodynamics ◽  
Disaster Mitigation ◽  
Sph Method ◽  
Landslide Event ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Simulation Results ◽  
Mitigation Design ◽  
The Impact

Abstract Flow-type landslide is one type of landslide that generally exhibits characteristics of high flow velocities, long jump distances, and poor predictability. Simulation of it facilitates propagation analysis and provides solutions for risk assessment and mitigation design. The smoothed particle hydrodynamics (SPH) method has been successfully applied to the simulation of two-dimensional (2D) and three-dimensional (3D) flow-like landslides. However, the influence of boundary resistance on the whole process of landslide failure is rarely discussed. In this study, a boundary algorithm considering the friction is proposed, and integrated into the boundary condition of the SPH method, and its accuracy is verified. Moreover, the Navier-Stokes equation combined with the non-Newtonian fluid rheology model was utilized to solve the dynamic behavior of the flow-like landslide. To verify its performance, the Shuicheng landslide event, which occurred in Guizhou, China, was taken as a case study. In the 2D simulation, a sensitivity analysis was conducted, and the results showed that the shearing strength parameters have more influence on the computation accuracy in comparison with the coefficient of viscosity. Afterwards, the dynamic characteristics of the landslide, such as the velocity and the impact area, were analyzed in the 3D simulation. The simulation results are in good agreement with the field investigations. The simulation results demonstrate that the SPH method performs well in reproducing the landslide process, and facilitates the analysis of landslide characteristics as well as the affected areas, which provides a scientific basis for conducting the risk assessment and disaster mitigation design.

Smoothed Particle Hydrodynamics into the Fluid Dynamics of Classical Problems

2016 ◽  
Vol 846 ◽  
pp. 73-78 ◽  
Author(s):  
Maziar Gholami Korzani ◽  
S. Galindo Torres ◽  
Alexander Scheuermann ◽  
David J. Williams
Keyword(s):  
Fluid Dynamics ◽  
Analytical Solutions ◽  
Poiseuille Flow ◽  
Smoothed Particle Hydrodynamics ◽  
Slip Boundary Condition ◽  
Sph Method ◽  
Slip Boundary ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Computational Fluid Dynamics Cfd

The study concerns the application of the Smoothed Particle Hydrodynamics (SPH) method within the computational fluid dynamics (CFD). In the present study, some classical problems – the Poiseuille flow, the Hagen-Poiseuille flow, and the Couette flow – with the analytical solutions were investigated to verify a newly developed code of SPH. The code used for solving these problems, is an entirely parallel SPH solver in 3D and has been developed by the authors. Fluid was modelled as a viscous liquid with weak compressibility. The boundary walls were simulated with a special set of fixed boundary particles, and no-slip boundary condition was considered. Computational results were compared to available analytical solutions for transient hydraulic processes. Good agreement is achieved for the whole transient stage of the considered problems until steady state is reached. The results of this study highlight the potential of SPH to tackle a broad range of problems in fluid mechanics.

A STABLE LARGE DEFORMATION CORRECTED SPH METHOD BASED ON STABILIZED CONFORMING NODAL INTEGRATION AND LAGRANGIAN KERNELS

2012 ◽  
Vol 09 (04) ◽  
pp. 1250057
Author(s):  
S. WANG
Keyword(s):  
Large Deformation ◽  
Smoothed Particle Hydrodynamics ◽  
Solid Mechanics ◽  
Particle Methods ◽  
Sph Method ◽  
Nodal Integration ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Meshless Approximation ◽  
Complex Phenomena

In this paper, we propose a Galerkin-based smoothed particle hydrodynamics (SPH) formulation with moving least-squares meshless approximation, applied to solid mechanics and large deformation. Our method is truly meshless and based on Lagrangian kernel formulation and stabilized nodal integration. The performance of the methodology proposed is tested through various simulations, demonstrating the attractive ability of particle methods to handle severe distortions and complex phenomena.

scholarly journals SPH Simulations of the Chemical and Dynamical Evolution of the Galactic Bulge

1993 ◽  
Vol 153 ◽  
pp. 395-396
Author(s):  
T. Tsujimoto ◽  
K. Nomoto ◽  
T. Shigeyama ◽  
Y. Ishimaru
Keyword(s):  
Distribution Function ◽  
Galaxy Formation ◽  
Smoothed Particle Hydrodynamics ◽  
Heavy Element ◽  
Dynamical Evolution ◽  
Galactic Bulge ◽  
Abundance Distribution ◽  
Sph Method ◽  
Particle Hydrodynamics ◽  
Smoothed Particle

We simulate the chemical and dynamical evolution of the galactic bulge with the smoothed particle hydrodynamics (SPH) method. We calculate the early phase of galaxy formation in which the bulge is formed through a burst of star formation. The calculated abundance distribution function of stars in the bulge is consistent with the observations of bulge K giants, if the heavy element yields are three times larger than those expected from Salpeter's IMF.

MODELLING URBAN COASTAL FLOODING THROUGH 2-D ARRAY OF BUILDINGS USING SMOOTHED PARTICLE HYDRODYNAMICS

2017 ◽  
pp. 37
Author(s):  
Sohaib Rashid Sulaiman Alahmed ◽  
Qingping Zou
Keyword(s):  
Smoothed Particle Hydrodynamics ◽  
Complex Flow ◽  
Sph Method ◽  
Flooding Event ◽  
Particle Hydrodynamics ◽  
Flow Features ◽  
Sph Model ◽  
Smoothed Particle ◽  
Flood Characteristics ◽  
Water Elevation

A Smoothed Particle Hydrodynamics (SPH) method is used to investigate the flood characteristics occurring in an idealized city with two different building layouts: aligned layout and 22.5o skewed layout with respect to the direction of the incoming flow. The model results show that the water elevation is higher for the skewed city layout than that for the aligned city layout. The force due to the flood impact on the majority of buildings tend to be higher for the former than that for the latter. The complex flow features including a hydraulic jump during the flooding event are well captured by the SPH model.

Shock Analysis of Underwater Explosion Using Smoothed Particle Hydrodynamics

2004 ◽  
Author(s):  
S. Matsumoto ◽  
S. Itoh
Keyword(s):  
Smoothed Particle Hydrodynamics ◽  
Underwater Explosion ◽  
Experimental Result ◽  
Governing Equations ◽  
Detonation Products ◽  
Sph Method ◽  
Equation Of States ◽  
Cylindrical Coordinate ◽  
Particle Hydrodynamics ◽  
Smoothed Particle

A blasting process includes large deformations and inhomogeneities caused by shock waves as well as the detonation gases generated by explosives. Smoothed Particle Hydrodynamics (SPH) is a meshless and complete Lagrangian method. The properties of SPH method can overcome the difficulty of a simulation in a blasting process. In this study, the simulation of an underwater explosion using SEP (Safety Explosives) as a cylindrical high explosive is carried out to confirm the advantage of SPH method for the analysis in a blasting process. The Euler equations are used for the governing equations of both water and the detonation products of the explosive. The Jones-Wilkins-Lee (JWL) equation and the Mie-Gru¨neisen equation are used as the equation of states for the detonation products and water, respectively. The two-dimensional and axisymmetrical simulation in cylindrical coordinate system is adopted to analyze the underwater explosion. The simulation result is compared with the experimental result and shows that SPH method can well simulate the underwater explosion.

3D Numerical Wave Basin Based on Parallelized SPH Method

2014 ◽  
Author(s):  
Hongjie Wen ◽  
Bing Ren
Keyword(s):  
Solitary Wave ◽  
Smoothed Particle Hydrodynamics ◽  
Large Diameter ◽  
Regular Wave ◽  
Sph Method ◽  
Submerged Breakwater ◽  
Wave Basin ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Numerical Wave

A viscous 3D numerical wave basin for high nonlinear waves was developed based on Smoothed Particle Hydrodynamics (SPH) method. The computational accuracy of SPH method is mainly improved by introducing the Corrective Smoothed Particle Hydrodynamics Method (CSPM) and a novel pressure correction scheme. The incident waves are generated from the inflow boundary by prescribing a velocity profile of the flap-type wavemaker motions, and the outgoing waves are numerically dissipated inside an artificial damping zone located at the end of the basin. Moreover, the parallelization of the improved 3D SPH scheme has been carried out using a hybrid MPI-OpenMP programming, together with a dynamic load balancing strategy to improve the computational efficiency. The generation and propagation of regular wave and solitary wave have been simulated. Wave forces induced by regular wave acting on a large-diameter circular cylinder and solitary wave passing over a submerged breakwater are also presented to verify the accuracy of SPH model. In addition, several computing cases of different particle resolutions are investigated and a high parallel efficiency is obtained.

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