# EngineeringCFD General Presentation - Web Version

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```					EngineeringCFD
Specialists
In Fluid Dynamics
Contents

I.     EngineeringCFD
II.    Introduction to CFD
III.   Capabilities and Scope
IV.    Multiphase Examples
V.     Case Studies
VI.    Summary
Principle Engineer

Curtis Marsh
• 13 years design experience for the
chemical process industry.
• Expert Computational Fluid
Dynamics (CFD) analyst.
• Specialising in multiphase and
multiphysics simulations.
• Proven technical ability supported by
excellent inter-personal skills.
Design Services

Rusal
Vaudreuil
FLSmidth

Windalco
Equipment                        Engineering
Suppliers                      Consultancies
RioTinto
Alcan
QAL
Chemical Process                          Yarwin
Plants           SKM
Momentum
Fonterra
Hulme Supercars
Project Integration
What is CFD?

• CFD = Computational Fluid Dynamics
– Computer models that predict how fluids behave

– Uses mathematical models to describe aspects of
fluid behaviour

– Use commercial CFD software from ANSYS

– Based on the finite volume approach

Know the basics?
CFD – Step 1

Geometry Creation
• Create from 2D
drawings
• Import from a range
– Parasolid
– IGES
– STEP
– ACIS
CFD – Step 2

• Develop mesh
• Define boundary
conditions
CFD - Step 3

• Setup boundary
conditions
• Initialise solution
CFD – Step 4

• Iterate to
convergence
problems
– Transient problems
CFD – Step 5

• Post-Process
Results
• Quantify
–   Mass flux
–   Velocities
–   Pressures
–   Forces
–   Lift/Drag
–   Free surface
CFD Capabilities

• Single phase          • Heat transfer

• Multiple phases       • Mass transfer

• Chemical species      • Phase change

• Chemical reactions    • Mechanical movement

• Combustion            • Ventilation

• Erosion               • Solidification
Equipment Types
•   Piping systems     •   Agitators
•   Pressure vessels   •   Mixing devices
•   Cyclones           •   Choke valves
•   Dryers             •   Gas dispersion
•   Filters            •   Gas lift devices
•   Calciners          •   Slug catchers
•   Furnaces
•   Burners
•   Tanks
•   Flash vessels
•   Overflows
•   Launders
•   Pumps
Multiphase Examples
Free Surface
Model
Can be applied to:
Launders/Overflows

Sloshing in Tanks

Slug Flow

Gas-Liquid Separators

Water-Oil Separation

(engineeringCFD.com)
Multiphase Examples
Discrete Phase
Model
Can be applied to:
Particle separation

Particle impact

Sprays

Droplets

Erosion
Multiphase Examples

Granular
Solids Flows
Can be applied to:
Cyclones

Pneumatic conv.

Settling solids

(engineeringCFD.com)
Multiphase Examples
Rotating
Equipment
Can be applied to:
Agitated Tanks

Pumps

Blowers

Compressors

(engineeringCFD.com)
Case Studies

• Project examples

– Flashing Flows (Rusal Aughinish)

– Alumina Calciners (FLSM/RioTinto/SKM)

– Segregated Fluids
CASE STUDY:
FLASHING FLOWS
Rusal Aughinish
Ireland
Alumina Refinery
1.8 million tonnes pa.
Flashing Flows
Complex multiphase flow
• Historically difficult to design
• Rapid phase change from
liquid to vapour
• Potentially extreme erosion
rates
Objective
• Design a balanced system
which maintains stable levels
within each vessel
Calculation Steps

FLUENT    Determine Flow Field

Saturation Temp

Super Heat

EngineeringCFD     Bubble Nucleation
Subroutine

Interfacial Area

Mass & Energy Transfer
Validation

Experiment   7.01 kg/s

Calculated   7.12 kg/s
Flow
(+1.6%)
Flash Vessels

• Project scope was
to determine the             Orifice
effect of piping              Plate
modifications

Process Data      910 kg/s

Calculated Flow   980 kg/s

(+8%)
Flash Tank Projects

Application of the Flashing Flow Model
– Piping design for multiphase flow

– Orifice plate sizing

– Evaluation of proposed vessel modifications

– Development of new inlet nozzles to improve
separation within flash vessels.
CASE STUDY:
ALUMINA CALCINERS
FLSmidth
RioTinto Alcan
Rusal Aughinish
Sinclair Knight Merz
Queensland Alumina
Design Challenges
• Complex processes
– Combustion / pyrolytic reactions
– Heat Transfer
• And complex problems
– Particle breakdown
– Refractory erosion
– Emission targets
– Limits on production
Calciner Furnaces
Complex coupled
physical processes
–   Combustion            Solids

–   Calcination process
–   Heat Transfer
–   Changing gas
composition
Burners    Gas Flow
Calciner Furnaces

(engineeringCFD.com)
Projects
• Many projects have benefited from our
modelling expertise
– Development of new furnace geometries
(RUSAL/FLSM)
– Change gas distribution to improve combustion
(RUSAL)
– Modify geometry to increase capacity
(SKM)
– Developed new hydrate feed points
(RioTinto/FLSM)
CASE STUDY:
SEGREGATED FLUIDS
Segregated Fluids

VOF free                             VOF Model
surface model
• Suitable for a   Gas Mass Flux
wide range
of flow
regimes

Liquid Mass Flux
Fluid Properties

• Key Physical Processes
– Surface tension

– Wall contact angle

– Compressibility of gas phase

– Pressure distribution

– Wall/body interaction forces
Pipe Flow Example

Ideal Gas
ρ = 50 kg/m3

Surface Tension
0.014 N/m
Light Liquid
ρ = 700 kg/m3
Surface Tension
0.1 N/m

Heavy Liquid
ρ = 1200 kg/m3              Contact Angles
90 degrees
Complex Flow

(engineeringCFD.com)
EngineeringCFD

Adding Value to the design process:
• Proof of concept

• Determine key design variables

• Extract key performance data

• Explore the full design envelope

• Problem solving new & existing equipment
EngineeringCFD

Ultimately EngineeringCFD provides:
• Rapid project development

• Risk mitigation

• Reduced commissioning/maintenance costs

• Greater process efficiencies
EngineeringCFD.com

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