December 20, 2016
- The most popular and widely used among them.
- Has been applied to various fluid flows involving diverse physical phenomena, from astrophysical to non-Newtonian fluid flows, but also to structure deformation and fracturing.
- Expanding very quickly among the academia and the industry.
- To be compared to the traditional numerical methods in CFD – typically, finite-difference/finite-element/finite-volume methods combined with volume-of-fluid/level-set methods -, which rely on a Eulerian, mesh-based approach.
- Much more recent research area (e.g., first application to free-surface flows in 1994) , but already starting to outperform the traditional methods on certain kinds of scenarios.
What are the main advantages?
- No advection term to model.
- No need for generating or adapting a mesh.
- No need for a tracking interface method, such as volume-of-fluid/level-set methods.
What are the main disadvantages ?
- Higher computational cost for approximating the spatial derivatives.
- More difficulties for prescribing the boundary conditions.
For what kinds of flows it tends to be preferred?
- Violent, convection-dominated dynamics (1).
- Large deformation of the fluid domain (2).
- Interactions with geometrically complex structures (3).
- Interactions with highly deforming/moving structures (4).
- Multi-phase processes (e.g., air-water mixtures, sediment flows, granular flows) (5).
Typical Scenarios in the Industry Industry
- Tsunami wave impact: (1)+(2)+(3)
- Dam break-induced: (1)+(2)+(3)
- Internal flooding: (2)+(3)
- High wind impact: (1)+(3)+(4)
- Radioactive Particles/Debris Tracking (4)+(5)
- Ability to handle Implicit-Incompressible and Compressible Flows
- Could be easily integrated into the Moose framework
– Ability to compute on HPC Machines (Falcon and other linux/windows clusters)
– Ability to couple other simulations from other 2D/3D domains
- Coupling with Shallow Water code
– Example: GeoClaw/Neutrino Coupling (Dam Breaks simulated)
– Example: SWASH/Neutrino Coupling (Lake Break Simulated)
- Coupling from Varying Scales
- From Geographic Scales to a localized representation
- Coupling with Bernoulli’s Model or Torricelli’s Model
- Ability to model Rain water based inflow
- Ability to model Pipe flows
- Coupling with Rigid Body Solvers
– Linear and Angular Momentum conservation with accurate Rigid-Fluid Coupling
– Example: Bullet-Physics
- Validated Results (Impact Force) on Rigids
– Example: Dam Break Scenario
– Flexible Open Boundaries for inflow and outflow conditions
– Easy Setup of Periodic Boundaries
– Easy Coupling with other PRA Systems (EMRALD) – Tested
– Easy setup of Particle Deamons for optimizing computations
– Mass conserving Killers/Emitters/Transporters
– Has been used in a variety of Industry Level Applications
- Pipe Breaks
- Rain induced Flooding
- Lake Breaches impacting structures
- Lake Overtopping
- Tsunami induced flooding
- Room Level Flooding affecting components and Real-time feedback
– Variable resolution to compromise accuracy for speed
- Almost Real-time feedback/coupling with PRA systems
- Easy import of geometry from various architectural/engineering formats
- Easy setup of model for simulation and visualization.
- Easy setup of initial conditions of Fluids using Volumetric Operations (Booleans)
- GPGPU Version and Distributed version currently under development.
- Cross Platform (Windows/Linux)
For what kind of flows the traditional/mesh based methods tend to be preferred?
- Nearly-steady regime.
- Turbulent regime in confined domain.
- Interactions with simple shaped, static rigid structures.