|
|
| Line 16: |
Line 16: |
| | | | |
| | '''[[Introductory SPH Iceberg-capsize Simulations]]''' | | '''[[Introductory SPH Iceberg-capsize Simulations]]''' |
| − |
| |
| − | {{#ev:youtube|B9TRacHKikE}}
| |
| − | {{#ev:youtube|r6vm1F5vpmM}}
| |
| − |
| |
| − | [[SPH Supporting Animations|Supporting Animations]]
| |
| − |
| |
| − | Animations from SPH on front page Periodic Boundary Conditions
| |
| − |
| |
| − | Click on video and takes to Smoothed Particle Hydrodynamics page
| |
| − |
| |
| − | Link from Current Research section> Smoothed Particle Hydrodynamics
| |
| − |
| |
| − | Periodic Boundary Condition Simulations
| |
| − |
| |
| − | In this model a fluid is initially held in a square configuration along a sloped ramp with
| |
| − |
| |
| − | open boundaries on both sides. At the the first time step the fluid is allow to flow outward due to
| |
| − |
| |
| − | the force of gravity and begins to flow down the ramp. Once the fluid particles meet the boundary
| |
| − |
| |
| − | edge on the right they cross over to the left side of the ramp. During the first few time steps the
| |
| − |
| |
| − | fluid quickly moves to fill the void on the upper left hand side and crashes with slower moving
| |
| − |
| |
| − | particles creating a significant splashing effect and the formation of a standing wave. Throughout
| |
| − |
| |
| − | the simulation this standing wave begins to die out as the flow approaches a state of equilibrium.
| |
| − |
| |
| − | Title: Exploring the method of smoothed particle hydrodynamics (SPH) and its application to
| |
| − |
| |
| − | icebergcapsize dynamics
| |
| − |
| |
| − | Lynn Kaluzienski, 9/20/2015, University of Maine
| |
| − |
| |
| − | Analytical solutions for problems in fluid dynamics are unavailable for most real world
| |
| − |
| |
| − | flows. The method of Smoothed Particle Hydrodynamics (SPH) was initially developed for
| |
| − |
| |
| − | astrophysical problems and has since been used to formulate approximate solutions for equations
| |
| − |
| |
| − | in fluid dynamics, chiefly the Navier Stokes solution for a weakly compressible fluid. SPH takes
| |
| − |
| |
| − | the innovative approach of replacing a fluid with an array of particles and solving the Navier
| |
| − |
| |
| − | Stokes equation on a particle by particle basis. A smoothing function is applied to each individual
| |
| − |
| |
| − | particle to determine the influence of its neighbors within a certain radius giving more weight to
| |
| − |
| |
| − | nearby particles. SPH is naturally a meshfree Lagrangian method, providing several benefits over
| |
| − |
| |
| − | former gridbased techniques in capturing surface accelerations and removing the need of tracking
| |
| − |
| |
| − | fluid boundaries. One difficulty with the SPH method is the need for a large quantity of particles to
| |
| − |
| |
| − | achieve the same precision as a gridbased approach. However, recent improvements in
| |
| − |
| |
| − | computational power such as the widespread use of graphic processing units (GPUs) have made
| |
| − |
| |
| − | SPH implementation feasible and computationally inexpensive. Several open source codes, such as
| |
| − |
| |
| − | DualSPHysics, make high resolution SPH simulations easily achievable on computers with
| |
| − |
| |
| − | multiple GPU processing units. Depending on complexity, several hundred thousand particle
| |
| − |
| |
| − | simulations can be achieved on the order of minutes to hours on a desktop computer. Largerscale
| |
| − |
| |
| − | models with millions to even billions of particles can be efficiently computed on supercomputers.
| |
| − |
| |
| − | The University of Maine SECS Numerical Laboratory currently has SPH simulations running on
| |
| − |
| |
| − | multiple GPUs. In addition, our collaboration with the Advanced Computing Group at Umaine will
| |
| − |
| |
| − | allow us to run increasingly complex and higher resolution simulations on one of their
| |
| − |
| |
| − | supercomputers in the near future.
| |
| − |
| |
| − | Supporting Literature: Crespo et al 2015, Monaghan 2012
| |
| − |
| |
| − | Link> Supporting Animations
| |
| − |
| |
| − | Each of these representations was exported from Paraview, a powerful visualization tool that stores
| |
| − |
| |
| − | all output parameters (pressure, density, velocity, acceleration, vorticity, ID number) for each
| |
| − |
| |
| − | particle at every time step.
| |
| − |
| |
| − | Dambreak Simulation
| |
| − |
| |
| − | In this model a fluid is initially held in a block configuration. At the first time step the fluid is
| |
| − |
| |
| − | allowed to flow out due to the force of gravity. As if flows outward it crashes into a rectangular
| |
| − |
| |
| − | block and interacts with the boundary walls. The color of each fluid particle corresponds to its
| |
| − |
| |
| − | velocity magnitude (m/s) at each time step.
| |
| − |
| |
| − | Initial Velocity Simulation
| |
| − |
| |
| − | In this model two fluids with spherical and square configurations are given initial velocities. As
| |
| − |
| |
| − | they collide with the square surface in the center they interact within a boxed boundary. The color
| |
| − |
| |
| − | of each fluid particle corresponds to its velocity magnitude (m/s) at each time step.
| |
| − |
| |
| − | WaveMaker Simulation
| |
| − |
| |
| − | In this model an oscillating piston creates wave within a fluid. The color of each fluid particle
| |
| − |
| |
| − | corresponds to its ID number, thereby illustrating the effect of mixing throughout the simulation.
| |
| − |
| |
| − | Link> Introductory SPH Icebergcapsize Simulations
| |
| − |
| |
| − | Wave Tank Experiment Simulation
| |
| − |
| |
| − | In this model an oscillation piston creates waves within a 250 cm x 50 cm x 50 cm tank. A solid
| |
| − |
| |
| − | block of 900 kg/m^3 density floats on one side of the tank and capsizes under the influence of the
| |
| − |
| |
| − | standing waves.The color of each fluid particle corresponds to its velocity magnitude (m/s) at each
| |
| − |
| |
| − | time step.
| |
| − |
| |
| − | Iceberg Closeup
| |
| − |
| |
| − | In this view the motion of the particles at the boundary of the model iceberg are shown. The color
| |
| − |
| |
| − | of each solid particle corresponds to its acceleration magnitude (m/s^2) at each time step.
| |
