Smoothed Particle Hydrodynamics Simulation of Oil-Jet Gear Interaction1

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Marc C. Keller ◽  
Samuel Braun ◽  
Lars Wieth ◽  
Geoffroy Chaussonnet ◽  
Thilo F. Dauch ◽  
...  
Keyword(s):  
Smoothed Particle Hydrodynamics ◽  
Single Phase ◽  
Jet Impingement ◽  
Spur Gear ◽  
Computational Effort ◽  
Computational Time ◽  
Resistance Torque ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Oil Jet

In this paper, the complex two-phase flow during oil-jet impingement on a rotating spur gear is investigated using the meshless smoothed particle hydrodynamics (SPH) method. On the basis of a two-dimensional setup, a comparison of single-phase SPH to multiphase SPH simulations and the application of the volume of fluid method is drawn. The results of the different approaches are compared regarding the predicted flow phenomenology and computational effort. It is shown that the application of single-phase SPH is justified and that this approach is superior in computational time, enabling faster simulations. In the next step, a three-dimensional single-phase SPH setup is exploited to predict the flow phenomena during the impingement of an oil-jet on a spur gear for three different jet inclination angles. The oil’s flow phenomenology is described and the obtained resistance torque is presented. Thereby, a significant effect of the inclination angle on the oil spreading and splashing process as well as the resistance torque is identified.

Smoothed Particle Hydrodynamics Simulation of Oil-Jet Gear Interaction

2017 ◽  
Author(s):  
Marc C. Keller ◽  
Samuel Braun ◽  
Lars Wieth ◽  
Geoffroy Chaussonnet ◽  
Thilo F. Dauch ◽  
...  
Keyword(s):  
Smoothed Particle Hydrodynamics ◽  
High Speed ◽  
Single Phase ◽  
Jet Impingement ◽  
Spur Gear ◽  
Computational Time ◽  
Qualitative Comparison ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Oil Jet

In this paper the complex two-phase flow during oil-jet impingement on a rotating spur gear is investigated using the meshless Smoothed Particle Hydrodynamics (SPH) method. A comparison of single-phase SPH to multi-phase SPH simulation and the application of the Volume of Fluid method on the basis of a two-dimensional setup is drawn. The results of the different approaches are compared regarding the predicted flow phenomenology and computational effort. It is shown that the application of single-phase SPH is justified and that this approach is superior in computational time, enabling faster simulations. In a next step, a three-dimensional single-phase SPH setup is exploited to predict the flow phenomena during the impingement of an oil-jet on a spur gear for various jet inclination angles. Thereby, a significant effect of the inclination angle on the oil spreading and splashing process is revealed. Finally, a qualitative comparison to an experimental high-speed image shows good accordance.

scholarly journals Smoothed Particle Hydrodynamics Simulation of a Mariculture Platform under Waves

Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2847
Author(s):  
Feng Zhang ◽  
Li Zhang ◽  
Yanshuang Xie ◽  
Zhiyuan Wang ◽  
Shaoping Shang
Keyword(s):  
Smoothed Particle Hydrodynamics ◽  
Graphics Processing Units ◽  
Degrees Of Freedom ◽  
High Tide ◽  
Theoretical Data ◽  
Emergency Evacuation ◽  
Water Levels ◽  
Computational Time ◽  
Particle Hydrodynamics ◽  
Smoothed Particle

This work investigates the dynamic behaviors of floating structures with moorings using open−source software for smoothed particle hydrodynamics. DualSPHysics permits us to use graphics processing units to recreate designs that include complex calculations at high resolution with reasonable computational time. A free damped oscillation was simulated, and its results were compared with theoretical data to validate the numerical model developed. The simulated three degrees of freedom (3−DoF) (surge, heave, and pitch) of a rectangular floating box have excellent consistency with experimental data. MoorDyn was coupled with DualSPHysics to include a mooring simulation. Finally, we modelled and simulated a real mariculture platform on the coast of China. We simulated the 3−DoF of this mariculture platform under a typical annual wave and a Typhoon Dujuan wave. The motion was light and gentle under the typical annual wave but vigorous under the Typhoon Dujuan wave. Experiments at different tidal water levels revealed an earlier motion response and smaller motion range during the high tide. The results reveal that DualSPHysics combined with MoorDyn is an adaptive scheme to simulate a coupled fluid–solid–mooring system. This work provides support to disaster warning, emergency evacuation, and proper engineering design.

Validation Study of Smoothed Particle Hydrodynamics in Fluid and Structure Interaction and the Comparison to Boundary Element Method

2017 ◽  
Author(s):  
Nhu Nguyen ◽  
Krish P. Thiagarajan ◽  
Matthew Cameron
Keyword(s):  
Boundary Element Method ◽  
Boundary Element ◽  
Smoothed Particle Hydrodynamics ◽  
Computational Time ◽  
Floating Structure ◽  
Structure Interaction ◽  
Advantages And Disadvantages ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Element Method

The purpose of this research is to validate the usage of Smoothed Particle Hydrodynamics (SPH) method in solving fluid-structure interaction problems as well as study its advantages and disadvantages compared to another well-known technique Boundary Element Method (BEM). The goal is achieved by 1) evaluating the Response Amplitude Operator (RAO) and 2) analyzing the drifting motion of a 1:10 scaled 3m-discus oceanographic buoy developed by the National Oceanographic and Atmospheric Administration (NOAA), using both experimental and numerical approaches. For the experimental study, the testing was carried out in an 8-m long wave tank and the buoy motions were measured using non-intrusive techniques. For numerical analysis, the project used DualSPHysics — open source code — and ANSYS AQWA — one of the leading software widely used in the marine applications — to simulate all the experimental scenarios via SPH and BEM techniques respectively. It is observed that while BEM has clear advantages in computational time and the ability to study applicable range of frequencies, SPH, in addition to its capability to simulate drifting motion of the floating structure, has shown to outperform the RAO predictions from BEM (especially in low frequency region). In higher frequency regions, the lack of experimental data hinders the conclusion on which method might be more suitable, as both have their own limitations.

Multiscale Thermal Transport Across Solid-Solid Interfaces

2010 ◽  
Author(s):  
Ganesh Balasubramanian ◽  
Ravi Kappiyoor ◽  
Ishwar K. Puri
Keyword(s):  
Smoothed Particle Hydrodynamics ◽  
Thermal Transport ◽  
Phonon Scattering ◽  
Periodic Boundary Conditions ◽  
Multiscale Model ◽  
Md Simulations ◽  
Computational Time ◽  
Mesoscale System ◽  
Particle Hydrodynamics ◽  
Smoothed Particle

We propose a novel multiscale model in order to better understand thermal transport across solid-solid interfaces in a mesoscale system. While Molecular Dynamics (MD) simulations tend to be very accurate, they are also computationally rather expensive. Continuum simulations such as Symmetric Smoothed Particle Hydrodynamics (SSPH), cannot take temperature discontinuities that may occur across interfaces into account, which can cause erroneous results. As such, we develop a multiscale model in which we run MD simulations over the region containing the interface, while running SSPH simulations over the remainder of the domain. This drastically reduces the number of molecules simulated by MD, reducing computational time, while hopefully still maintaining the accuracy provided by a “pure” MD run. Results from the simulation indicate that when boundary temperatures are specified, the data from the multiscale model is highly similar to the data from the pure MD run. However, when boundary fluxes are specified, the multiscale model tends to predict higher temperatures than does MD. We believe that this may be due to continuum SSPH simulations being unable to take into account phonon scattering with non-periodic boundary conditions.

A Comparison of Smoothed Particle Hydrodynamics (SPH) and Coupled SPH-FEM Methods for Modeling Machining

2020 ◽  
Author(s):  
Nishant Ojal ◽  
Harish P. Cherukuri ◽  
Tony L. Schmitz ◽  
Adam W. Jaycox
Keyword(s):  
Smoothed Particle Hydrodynamics ◽  
Solid Mechanics ◽  
Large Deformations ◽  
Computational Time ◽  
Depth Of Cut ◽  
Fe Model ◽  
Sph Method ◽  
Particle Hydrodynamics ◽  
Sph Model ◽  
Smoothed Particle

Abstract Smoothed Particle Hydrodynamics (SPH), a particle-based, meshless method originally developed for modeling astrophysical problems, is being increasingly used for modeling fluid mechanics and solid mechanics problems. Due to its advantages over grid-based methods in the handling of large deformations and crack formation, the method is increasingly being applied to model material removal processes. However, SPH method is computationally expensive. One way to reduce the computational time is to partition the domain into two parts where, the SPH method is used in one segment undergoing large deformations and material separation and in the second segment, the conventional finite element (FE) mesh is used. In this work, the accuracy of this SPH-FEM approach is investigated in the context of orthogonal cutting. The high deformation zone (where chips form and curl) is meshed with the SPH method, while the rest of the workpiece is modeled using the FE method. At the interface, SPH particles are coupled with FE mesh for smooth transfer of stress and displacement. The boundary conditions are applied to tool and FE zone of the workpiece. For comparison purposes, a fully-SPH model (workpiece fully discretized by SPH) is also developed. This is followed by a comparison of the results from the coupled SPH-FE model with the SPH model. A comparison of the chip profile, the cutting force, the von Mises stress and the damage parameter show that the coupled SPH-FE model reproduces the SPH model results accurately. However, the SPH-FE model takes almost 40% less time to run, a significant gain over the SPH model. Similar reduction in computation time is observed for in a micro-cutting application (depth of cut of 300 nm). Based on these results, it is concluded that coupling SPH with FEM in machining models decreases simulation time significantly while still producing accurate results. This observation suggests that three-dimensional machining problems can be modeled using the combined SPH-FEM approach without sacrificing accuracies.

Multiphase Godunov-Type Smoothed Particle Hydrodynamics Method with Approximate Riemann Solvers

2018 ◽  
Vol 16 (02) ◽  
pp. 1846010 ◽  
Author(s):  
Zhi Wen Cai ◽  
Zhi Zong ◽  
Zhen Chen ◽  
Li Zhou ◽  
Chao Tian
Keyword(s):  
Smoothed Particle Hydrodynamics ◽  
Single Phase ◽  
Equations Of State ◽  
Riemann Problems ◽  
Riemann Solvers ◽  
Particle Pairs ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Smoothed Particle Hydrodynamics Method ◽  
Approximate Riemann Solvers

In this paper, a multiphase Godunov-type smoothed-particle hydrodynamics (MGSPH) method is presented for simulating multi-fluid Riemann problems with complex equations of state (EOSs). In this method, single-phase Riemann solvers are used between particles with same phase, and interfacial approximate Riemann solvers are introduced on the interfacial particle pairs. Various combinations of single-phase and interface approximate Riemann solvers are comparatively studied to find out the best combination for MGSPH. Five examples are presented to verify MGSPH method.

scholarly journals Experimental Validation of Single- and Two-Phase Smoothed Particle Hydrodynamics on Sloshing in a Prismatic Tank

2019 ◽  
Vol 7 (8) ◽  
pp. 247 ◽  
Author(s):  
Andi Trimulyono ◽  
Hirotada Hashimoto ◽  
Akihiko Matsuda
Keyword(s):  
Smoothed Particle Hydrodynamics ◽  
Single Phase ◽  
Sensitivity Analyses ◽  
Particle Methods ◽  
Local Pressure ◽  
Two Phase ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Tank Sloshing ◽  
Number Of Particles

This study aimed to validate the single-phase and two-phase smoothed particle hydrodynamics (SPH) on sloshing in a tank. There have been many studies on sloshing in tanks based on meshless particle methods, but few researchers have used a large number of particles because there is a limitation on the total number of particles when using only CPUs. Additionally, few studies have investigated the influence of air phase on tank sloshing based on two-phase SPH. In this study, a dedicated sloshing experiment was conducted at the National Research Institute of Fishing Engineering using a prismatic tank with a four-degrees-of-freedom forced oscillation machine. Three pressure gauges were used to measure local pressure near the corners of the tank. The sloshing experiment was repeated for two different filling ratios, amplitudes, and frequencies of external oscillation. Next, a GPU-accelerated three-dimensional SPH simulation of sloshing was performed using the same conditions as the experiment with a large number of particles. Lastly, two-dimensional sloshing simulations based on single-phase and two-phase SPH were carried out to determine the importance of the air phase in terms of tank sloshing. Based on systematic comparisons of the single-phase SPH, two-phase SPH, and experimental results, this paper presents a detailed discussion of the role of air-phase in terms of sloshing. The currently achievable accuracy when using SPH is demonstrated together with a few sensitivity analyses of SPH parameters.

Multi-Phase Gearbox Modelling Using GPU-Accelerated Smoothed Particle Hydrodynamics Method

2019 ◽  
Author(s):  
Muraleekrishnan Menon ◽  
Kamil Szewc ◽  
Vishal Maurya
Keyword(s):  
Smoothed Particle Hydrodynamics ◽  
Single Phase ◽  
Free Surface Flows ◽  
Base Case ◽  
Multiphase Model ◽  
Engineering Applications ◽  
Promising Alternative ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Lubricant Distribution

Abstract Developments in automotive design such as electrification of engines and a growing need to improve driveline efficiency requires adaption of old techniques. The ability to make fast and accurate Computational Fluid Dynamics (CFD) assessment is of high importance to the development of novel powertrains. Consequently, innovative numerical techniques and continuous improvements to existing CFD codes is relevant to ensure reliability. This work extends the capabilities of a Smoothed Particle Hydrodynamics (SPH) code to include multiphase modeling, studied using a gearbox model. A vast majority of CFD codes use grid-based approaches following the Eulerian spatial discretization, which is quite established in engineering applications. Lagrangian based approaches where the moving fluid particles are discretized over time and space present a promising alternative. One of the most common methods of this kind is the Smoothed Particle Hydrodynamics (SPH) method, a fully Lagrangian, particle-based approach for fluid-flow simulations. The main advantage is the absence of numerical grid for computations, which eliminates complexities of interface handling. Nowadays, the SPH approach is more commonly used for hydro-engineering applications involving free-surface flows. New techniques to perform numerical simulations on Graphics Processing Units (GPU) virtually eliminates some of the disadvantages of the method. In this work, we present our multi-GPU solution designed for both GPU-equipped desktops and multi-GPU supercomputers. Fluid dynamic simulations on a single gearbox model is used to validate the multiphase model, by comparing the results with earlier simulations that use a single-phase model omitting air-lubricant interface in the gearbox. The base case in the study is a single bevel gear placed inside a cuboid case with a lubricant depth equivalent to 25% gear diameter. Simulations are performed at various rotational speeds, and corresponding lubricant distribution and churning losses are obtained. The current study targets a comparison of the single-phase and multiphase models in approximating the lubricant distribution and churning loss values at nominal rotational speeds. This serves to standardize the numerical procedure, which will help in improving the accuracy of churning loss calculations through validations against experimental results in the future.

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