ansys applications in ocean science and engineering
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NATRANSCRIPT
© 2011 ANSYS, Inc. August 12, 20111
ANSYS Applications in Ocean
Science and Engineering
Marsall Loewenstein
Ian Lockley
8/10/2011
© 2011 ANSYS, Inc. August 12, 20112
Perspective
The Universe in One Year concept was inspired by the
late Cornell astronomer, Carl Sagan. Sagan was the first
person to explain the history of the universe in one
year—as a “Cosmic Calendar”—in his television series,
Cosmos
© 2011 ANSYS, Inc. August 12, 20113
Perspective
© 2011 ANSYS, Inc. August 12, 20114
1769
Benjamin Franklin’s first scientific study of the Gulf Stream. He measured
water temperatures during several Atlantic crossings and effectively
explained the phenomena.
11:59:59.5 seconds….
0.5 Seconds of Oceanographic History
© 2011 ANSYS, Inc. August 12, 20115
© 2011 ANSYS, Inc. August 12, 20116
1769
Benjamin Franklins first scientific study of the Gulf Stream. He measured
the water temperatures during several Atlantic crossings and effectively
explained tbe phenomena
1855
Physical Geography of the Sea, by Matthew Fontaine Maury published in
1855 was the first textbook of Oceanography.
0.5 Seconds of Oceanographic History
11:59:59.5 seconds….
© 2011 ANSYS, Inc. August 12, 20117
Relevance to Science / Engineering / Product Design
• The pace of academic endeavors, discovery and information continues to
grow at an exponential rate
• Scientists and Engineers are constantly challenged or asked to do more
with less
• Time and expense of developing industrial and research equipment test
must be reduced
• Quality and safety must continue to rise
• We must all be stewards of our precious environment
• “Cut and try” approaches in science and engineering must be
supplemented or replaced with simulation
• Many mature software tools exist from ANSYS, across an
enormous range of physical disciplines, which enable
research and the development and testing of both concepts
and products through physics based numerical simulation
© 2011 ANSYS, Inc. August 12, 20118
• Brief Introduction to ANSYS
• Selected Simulation Applications
– Environmental
– Pollution dispersion, cleanup, scouring,
ocean currents, noise …
– Energy
– Wave energy, tidal energy, energy
environmental impact
– Marine
– Hull design, propulsion, system design,
sensor design ….
Overview
© 2011 ANSYS, Inc. August 12, 20119
• Brief Introduction to ANSYS
• Selected Simulation Applications
– Environmental
– Pollution dispersion, cleanup, scouring,
ocean currents, noise …
– Energy
– Wave energy, tidal energy, energy
environmental impact
– Marine
– Hull design, propulsion, system design,
sensor design ….
Overview
© 2011 ANSYS, Inc. August 12, 201110
FocusedThis is all we do: Physics based software simulation tools for
science and engineering
Capable2,000 employees
60 locations, 40 countries
Trusted96 of top 100 FORTUNE 500 industrials
ProvenRecognized as one of the world’s most innovative
and fastest-growing companies*
A 40 year track record of innovation
IndependentLong-term financial stability
CAD agnostic
*BusinessWeek, FORTUNE
(image of engineer working through simulation problem)
Who is ANSYS
© 2011 ANSYS, Inc. August 12, 201111
In-house
Solution
One Picture of ANSYS
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Fluids
Thermal
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CAD
Import
Param-
terizationMeshing
Workflow
Post-
processing
PlantD(s)
y(t)u(t)+
-
ANSYS is the leading provider of
physics based engineering
software tools
• Structural
• Thermal
• Electromagnetics
and
• Fluids
© 2011 ANSYS, Inc. August 12, 201112
Industry Leading Customers
© 2011 ANSYS, Inc. August 12, 201113
Selected Academic Customers
© 2011 ANSYS, Inc. August 12, 201114
“By embedding ANSYS technology in our engineering curriculum, Cornell is producing
students who can go into industry with a strong foundation in the application of
advanced simulation.”
Professor Rajesh Bhaskaran
Cornell University
ANSYS Academic Program
Presence
• Academic products used at 2,400 institutions
worldwide, with nearly 87,000 licensed seats
Value to Industry
• Students trained in ANSYS join industry with
experience in simulation
• Research use of ANSYS helps tackle next-generation
industry challenges
Software Technology
• Academic partnerships ensure our product
technology leadership
Dr. Rajesh Bhaskaran
Cornell University
ANSYS Academic Program
© 2011 ANSYS, Inc. August 12, 201115
Typical Marine CFD Applications
• Hydrodynamics
• Ship hulls
• Submarines
• Yacht hulls, keels
• Appendages
• Other underwater systems
• Towed sonar arrays
• Propulsion
• Propeller / Hull interactions
• Water jets
• Cavitation
• Bubble wakes and signature
• Acoustics
• Aerodynamics
• Superstructures
• Dispersion
• Yacht Sails
• Exhaust plumes
• Ventilation
• Heli Deck operations
• Fire Suppression
• Halon replacement
• Blast interactions
• Fluid Structure Interaction
• Floating objects
• Flexible objects
• Vortex Induced Vibration
• Swim suits
• Heat transfer• Fuel Cells
• Wave slam
• Flooding in Ro-Ro ferries
• Cavitation
• Torpedoes
• Sloshing in tanks
• Submarine Reactors
• Structural vibrations
• Periscope / free surfaces
• Pumps• Offshore Power
generation
• Chemical reactions• Free surface flows• Microfluidics• Hypersonics• CVD
© 2011 ANSYS, Inc. August 12, 201116
• Brief Introduction to ANSYS
• Selected Simulation Applications
– Environmental
– Pollution dispersion, cleanup, scouring,
ocean currents, noise …
– Energy
– Wave energy, tidal energy, energy
environmental impact
– Marine
– Hull design, propulsion, system design,
sensor design ….
Overview
© 2011 ANSYS, Inc. August 12, 201117
© 2011 ANSYS, Inc. August 12, 201118
• Brief Introduction to ANSYS
• Selected Simulation Applications
– Environmental
– Pollution dispersion, cleanup, scouring,
ocean currents, noise …
– Energy
– Wave energy, tidal energy, energy
environmental impact
– Marine
– Hull design, propulsion, system design,
sensor design ….
Overview
© 2011 ANSYS, Inc. August 12, 201119
Environmental: Scouring
© 2011 ANSYS, Inc. August 12, 201120
Scouring: Challenges
© 2011 ANSYS, Inc. August 12, 201121
Scouring: Examples
© 2011 ANSYS, Inc. August 12, 201122
CFD modeling of scour around offshore wind turbines in areas with strong currents, Solberg et al, Conference on Offshore Wind Turbines Situated in Strong Sea Currents, 2006
© 2011 ANSYS, Inc. August 12, 201123
Advanced numerical modeling of the scouring process around the piers of a bridge, Motta et al, Proc of the congress, IAHR, 2007
© 2011 ANSYS, Inc. August 12, 201124
Illustration Problem
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Modeling Approach
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Initial Results
© 2011 ANSYS, Inc. August 12, 201127
Numerical simulation of scour around pipelines using an Euler-Euler coupled two-phase model, Zhao and Fernando, Environmental Fluid Mechanics, (2007)
© 2011 ANSYS, Inc. August 12, 201128
Environmental: Oil Spill and Cleanup
© 2011 ANSYS, Inc. August 12, 201129
Environmental: Oil Spill and Cleanup
© 2011 ANSYS, Inc. August 12, 201130
CFD Modeling of Oil Spill
Past CFD studies employed VOF approach to study oil spill
• Free surface was captured by VOF
• Linear wave profiles was used to describe wave boundary condition
• Studies were limited to 2D
• Studies were conducted for different wavelength and amplitude
30
© 2011 ANSYS, Inc. August 12, 201131
Current CFD Model
Full 3-dimensional Model
Volume of Fluid (VOF) – Approach• A single set of momentum equations is solved and the volume
fraction of each immiscible phase is tracked
• Three phases – Air, Water and Oil is considered
Open channel wave boundary condition -used
to prescribe wave motion
A fifth order stokes wave theory is used to
describe a non-linear wave
Turbulence – Realizable k-ε model
31
© 2011 ANSYS, Inc. August 12, 201132
3D CFD Model
32
2 KmOpen Channel
Boundary Inlet
Oil Inlet
Open Channel
Pressure Outlet
Top Surface - Outlet
Oil Spill Location
Around 565,000 Grid Elements Used
Grid refined near sea surface to capture waves
© 2011 ANSYS, Inc. August 12, 201133
Wave Profiles
33
5m Amplitude and 500m Wavelength Wave
10m Amplitude and 500m Wavelength Wave
5m Amplitude and 750m Wavelength Wave
© 2011 ANSYS, Inc. August 12, 201134
Wave Profile - Animation
34
5m amplitude and 500m Wavelength wave
© 2011 ANSYS, Inc. August 12, 201135
Wave Velocity Profiles
35
5m Amplitude and 500m Wavelength Wave
10m Amplitude and 500m Wavelength Wave
5m Amplitude and 750m Wavelength Wave
© 2011 ANSYS, Inc. August 12, 201136
Observations - Velocity Profiles
High velocity near surface due to waves
As wave steepness increase – Non linear waves results
Coastal region or Shallow water region impacts the wave profile
36
© 2011 ANSYS, Inc. August 12, 201137
Oil Slick at Sea Surface
37
5m Amplitude and 500m
Wavelength Wave
10m Amplitude and 500m
Wavelength Wave
5m Amplitude and 750m
Wavelength Wave
© 2011 ANSYS, Inc. August 12, 201138
Time History of Spread
38
5m amplitude and 500m Wavelength wave 10m amplitude and 500m Wavelength wave
© 2011 ANSYS, Inc. August 12, 201139
Time History of Spread
39
5m amplitude and 500m Wavelength wave 5m amplitude and 750m Wavelength wave
© 2011 ANSYS, Inc. August 12, 201140
Time History of Spread
40
5m amplitude and 500m Wavelength wave 5m amplitude and 500m Wavelength wave
0.1m/s - Wave Current
© 2011 ANSYS, Inc. August 12, 201141
Observations
Spread pattern is different for different wave
conditions
Polluted area increases with higher interaction
of wave and current
Polluted area is more towards coastal area or in
shallow water
High wave amplitude – oil traveled faster to the
coastal area – thus not spreading
41
© 2011 ANSYS, Inc. August 12, 201142
Conclusions
Overview of the oil spill and its impact on oil and gas
industry
Physics of oil spill – Hydrodynamics of Ocean waves
plays major role
Focused on shallow water waves – Dispersion of oil
slick is more
Need higher order wave theories as wave steepness
increase
42
© 2011 ANSYS, Inc. August 12, 201143
Conclusions
Presented a detailed 3D CFD based model for
study of oil spill• Volume of Fluid (VOF)
• Open channel wave boundary condition
Spread pattern is different for different wave
conditions
Polluted area increases with higher interaction
of wave and current
Value of using CFD based simulations for oil spill
scenarios43
© 2011 ANSYS, Inc. August 12, 201144
Environmental/Marine: Noise
© 2011 ANSYS, Inc. August 12, 201145
Environmental/Marine: Noise
MENCK hydraulic hammer
© 2011 ANSYS, Inc. August 12, 201146
Environmental/Marine: Noise
Comparison of measured and calculated underwater sound pressure at
a distance of 245 meters from the pile. Knowing the sound propagation
law for this region, the sound pressure at 750 meters can be calculated
and converted into decibels (dB).
© 2011 ANSYS, Inc. August 12, 201147
Environmental/Marine: Noise
Underwater sound generation and propagation
shown as a sequence of snapshots in time.
Within a steel pile, the speed of sound is about
5,000 meters per second, while the speed of
sound in water is about 1,500 meters per
second — resulting in radiation patterns and
specific inclination angle.
21
5
43
6
© 2011 ANSYS, Inc. August 12, 201148
• Brief Introduction to ANSYS
• Selected Simulation Applications
– Environmental
– Pollution dispersion, cleanup, scouring,
ocean currents, noise …
– Energy
– Wave energy, tidal energy, energy
environmental impact
– Marine
– Hull design, propulsion, system design,
sensor design ….
Overview
© 2011 ANSYS, Inc. August 12, 201149
Energy: Wave Energy
© 2011 ANSYS, Inc. August 12, 201150
Energy: Wave Energy
COLUMBIA POWER’s wave power system: The wings and vertical spar
react to the shape of the passing ocean swell. Each wing is coupled by a
drive shaft to turn its own rotary generator.
Wave direction
1 2 3
4 5
© 2011 ANSYS, Inc. August 12, 201151
Energy: Wave Energy
COLUMBIA POWER engineers doubled
efficiency of the buoy by using ANSYS AQWA to
optimize its geometry.
© 2011 ANSYS, Inc. August 12, 201152
Energy: Wave Energy
Maxwell computational
electromagnetics software
from ANSYS was used to
optimize the generator
design.
© 2011 ANSYS, Inc. August 12, 201153
• Brief Introduction to ANSYS
• Selected Simulation Applications
– Environmental
– Pollution dispersion, cleanup, scouring,
ocean currents, noise …
– Energy
– Wave energy, tidal energy, energy
environmental impact
– Marine
– Hull design, propulsion, system design,
sensor design ….
Overview
© 2011 ANSYS, Inc. August 12, 201154
Contours of pressure coefficient for the XF5 (left) and the new Kamewa CP-A (right). Insets: Photographs of the blade indicating the locations of the
simulation where cavitation is present (noticeable as pitting). ANSYS FLUENT results helped reduce pressure at the blade root in the CP-A design, indicated
by the lack of cavitation erosion present in the CP-A photo.
Rolls-Royce uses simulation for propeller design to reduce
marine fuel consumption.
According to a 2003 study from the University of Delaware, international
commercial and military shipping fleets consume approximately 289 million
metric tons of petroleum per year, which is more than twice the consumption of
the entire population of Germany. The ANSYS FLUENT simulations run on the
modified propeller geometry predicted that the efficiency would increase by 1
percent to 1.5 percent, and physical experiments confirmed that this was, in
fact, the case.
The new Kamewa
CP-A propeller
from Rolls-Royce
Marine
Propulsion Systems
© 2011 ANSYS, Inc. August 12, 201155
Propulsion Systems
Courtesy SVA-Potsdam (Potsdam Model Basin)
Cavitation Effects
For water pumps, marine propellers, and other
equipment involving hydrofoils, cavitation can cause
problems such as vibration, increased hydrodynamic
drag, pressure pulsation, noise, and erosion on solid
surfaces. Most of these problems are related to the
transient behaviour of cavitation structures. To better
understand these phenomena, unsteady 3D simulations
of cavitating flow around single hydrofoils are often
performed and the results are compared to experiments
Unsteady propeller cavitation in the wake of a ship
© 2011 ANSYS, Inc. August 12, 201156
Propulsion (including Cavitation)
Cavitating Flow Over a Hydrofoil
Cavitating flow over a cambered two-dimensional wing
section was simulated using ANSYS Fluent CFD solver. The
flow angle over the NACA 66 (MOD) hydrofoil is chosen to
represent conditions that are common in water pump and
marine propeller applications. Excellent agreement with
experimental data is obtained for mid-chord cavitation, and
satisfactory agreement is obtained at the trailing edge of the
cavitation region.
Pressure coefficient as a function of normalized chord length
showing ANSYS Fluent results compared with experimental data
Contours of vapour volume fraction show cavitation in the mid-chord region
© 2011 ANSYS, Inc. August 12, 201157
Marine: Sensor Design
© 2011 ANSYS, Inc. August 12, 201158
Marine: Sensor Design
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Marine: Sensor Design
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Marine: Sensor Design
© 2011 ANSYS, Inc. August 12, 201161
Conclusions
ANSYS offers a broad and technically deep set of
physics based research and engineering
software tools which foster understanding,
innovation as well as save time and money
ANSYS is a strong partner for both academic and
industrial organizations seeking such goals