fluent and multi phase flows
TRANSCRIPT
Fluent & Multiphase Flows
Salmane Saadani
Fluent Sweden AB
Historical Background The original FLUENT software was developed at the
University of Sheffield, UK in the 1970s (Tempest)
1983 title in FLUENT was transferred to a New HampshireCompany called ‘Creare’
1988 Fluent group at Creare becomes Fluent Inc.
1999 Fluent Sweden opened
2006 Fluent has become part of the Ansys Group.
Fluent Inc. HQ - Lebanon, NHEvanston, ILSanta Clara, CAAn Arbor, MIMorgantown, WV
N. America Europe Asia/PacificFluent UKFluent FranceFluent GermanyFluent ItalyFluent SwedenFluent Benelux
Fluent Asia-Pacific, JapanTokyo and OsakaFluent India
Worldwide Offices
Numerous offices worldwide in additionto various distributors
FLUENT SWEDEN
Services Software Sales
Technical support
Training
Consulting
14 Employees 5 Ph.D
5 Siv Ing
Fluent & Multiphase FlowsFluent Offers:
A wide range of proven and leading edgeMultiphase models.
Advanced meshing tools.
Optimal Parrallelization schemes
Worldwide experience and involvement inMultiphase Applications
Fluent & Multiphase Flows
It Means:
Accurate flow simulations
Accurate geometry representation
Quick solutions
Ability to solve unconventional problems
Multiphase Flow Regimes Bubbly flow/ Droplet flow/
Particle-laden flow = Discretesecondary phase structures(bubbles, droplets, solidparticles) in a continuousprimary phase
Slug flow = Large bubbles in acontinuous liquid
Annular flow = Continuousliquid along walls, gas in core
Stratified / Free-surface flow= Immiscible fluids separatedby a clearly-defined interface
Jet flow = thin liquid coresurrounded by bulk gas phase
Film flow = thin liquid layerflowing along wall boundaries
Bubbly flow / Droplet flow /Particle-laden flow
Slug flow
Annular flow
Jet flow Film flow
Free-surface flow
Fluent Multiphase Models
Volume of Fluid (VOF) Model (free-surface / stratifiedflows, filling, sloshing)
Mixture Model (bubbly, droplet, Granular Flow)
Discrete Phase Model (bubbly, droplet, particle-laden flowswith α ≤ 10%)
The Eulerian model (Advanced Particle Modeling)
• Kinetic theory of granular flows
• Population Balance Model
Population Balance Model Nucleation
Chemical Reaction
Phase change
• Boiling
Growth
Chemical Reaction
Crystal growth
Breakage
Particle-particle collisions
Turbulence and shear
Aggregation
Particle-particle collisions
Coagulation
Coalescence
Agglomeration
Time
Time
Nucleation: Creation of particles
Growth (Shrinkage)
Aggregation
Break-up
Meshing
•Tetraheadral
•Hexaheadral
•Multiple Mesh Type Combinations
•Hexcore Mesh
•Moving Deforming Mesh
•Polyheadral
Meshing
Hybrid Mesh
439,781 cellsPolyhedral Mesh
174,552 cells
Grid reduction by a factorof 3 to 5
Mixing Tank
1119006 cellsFine Tetrahedral Mesh
370549 cellsCoarse Tetrahedral Mesh
237404 cellsPolyhedral Mesh
Velocity Profiles Turbulent Kinetic Energy Profiles
Coarse Tetrahedral: 370,549 cellsFine Tetrahedral: 1,119,006 cellsPolyhedral: 237,404 cells
Geometry
0
0.2
0.4
0.6
0.8
1
1.2
0 0.1 0.2 0.3 0.4 0.5z/H
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
0 0.1 0.2 0.3 0.4 0.5z/H
Mixing Tank
13001850Polyhedral with PBCS
2700~41800Fine Tetrahedral with PBCS
Memory(MB)
Relative SingleCPU TimeIterations
Mixing Tank
ParallelParallel I/O Market leader in Parallel Performance Fast case and data file read/write Very Good ScalabilityOther Parallel Enhancements Load Balancing (Prevents Bottlenecking) Ability to read Hexcore meshes directly into
parallel without partitioning
FLUENT 6.3
Parallel Data File Write
9.834
5.282Xeon/GigE
5.612Opteron/Infiniband6.334
6.68
Speed-up
FLUENT 6.3/FLUENT 6.2
Numberof CPUs
Platform andInterconnect
Fluent Involvement
Fluent works closelywith industry leadersworldwide to push thelimit of CFD further
Conclusion FLUENT continues to
push the boundaries for More accurate flow simulations
More accurate geometrymodeling
Quicker solutions