ANSYS Applications in Ocean Science and Engineering

ANSYS Applications in Ocean Science and Engineering 1 Marsall Loewenstein Ian Lockley 8/10/2011

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 2

Perspective 3

0.5 Seconds of Oceanographic History 11:59:59.5 seconds. 1769 Benjamin Franklin s first scientific study of the Gulf Stream. He measured water temperatures during several Atlantic crossings and effectively explained the phenomena. 4

0.5 Seconds of Oceanographic History 11:59:59.5 seconds. 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. 6

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 7 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

Overview 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. 8

Who is ANSYS Focused This is all we do: Physics based software simulation tools for science and engineering Capable 2,000 employees 60 locations, 40 countries Trusted 96 of top 100 FORTUNE 500 industrials Proven Recognized as one of the world s most innovative and fastest-growing companies* A 40 year track record of innovation Independent Long-term financial stability CAD agnostic 10 *BusinessWeek, FORTUNE (image of engineer working through simulation problem)

One Picture of ANSYS ANSYS is the leading provider of physics based engineering software tools Paramterization Fluids Meshing Structural Thermal Electromagnetics and Fluids CAD Import Structural + - u(t) In-house D(s) Plant Solution y(t) Emag Thermal Workflow Postprocessing 11

Industry Leading Customers 12

Selected Academic Customers 13

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 14 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. Dr. Rajesh Bhaskaran Cornell University ANSYS Academic Program Professor Rajesh Bhaskaran Cornell University

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 15

Environmental: Scouring 19

Scouring: Challenges 20

Scouring: Examples 21

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 22

Advanced numerical modeling of the scouring process around the piers of a bridge, Motta et al, Proc of the congress, IAHR, 2007 23

Illustration Problem 24

Modeling Approach 25

Initial Results 26

Numerical simulation of scour around pipelines using an Euler-Euler coupled two-phase model, Zhao and Fernando, Environmental Fluid Mechanics, (2007) 27

Environmental: Oil Spill and Cleanup 28

Environmental: Oil Spill and Cleanup 29

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 30

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 31

3D CFD Model 2 Km Open Channel Boundary Inlet Top Surface - Outlet Open Channel Pressure Outlet Oil Spill Location Oil Inlet 32 32 Around 565,000 Grid Elements Used Grid refined near sea surface to capture waves

Wave Profiles 5m Amplitude and 500m Wavelength Wave 10m Amplitude and 500m Wavelength Wave 5m Amplitude and 750m Wavelength Wave 33 33

Wave Profile - Animation 5m amplitude and 500m Wavelength wave 34 34

Wave Velocity Profiles 5m Amplitude and 500m Wavelength Wave 10m Amplitude and 500m Wavelength Wave 5m Amplitude and 750m Wavelength Wave 35 35

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 36

Oil Slick at Sea Surface 5m Amplitude and 500m Wavelength Wave 10m Amplitude and 500m Wavelength Wave 5m Amplitude and 750m Wavelength Wave 37 37

Time History of Spread 5m amplitude and 500m Wavelength wave 10m amplitude and 500m Wavelength wave 38 38

Time History of Spread 5m amplitude and 500m Wavelength wave 5m amplitude and 750m Wavelength wave 39 39

Time History of Spread 5m amplitude and 500m Wavelength wave 5m amplitude and 500m Wavelength wave 0.1m/s - Wave Current 40 40

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 41

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 42

Conclusions 43 43 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 scenarios

Environmental/Marine: Noise 44

Environmental/Marine: Noise MENCK hydraulic hammer 45

Environmental/Marine: Noise 46 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).

Environmental/Marine: Noise 1 2 3 4 5 6 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. 47

Energy: Wave Energy 49

Energy: Wave Energy 1 2 3 Wave direction 4 5 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. 50

Energy: Wave Energy COLUMBIA POWER engineers doubled efficiency of the buoy by using ANSYS AQWA to optimize its geometry. 51

Energy: Wave Energy Maxwell computational electromagnetics software from ANSYS was used to optimize the generator design. 52

Propulsion Systems 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 54 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.

Propulsion Systems 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 55 Unsteady propeller cavitation in the wake of a ship Courtesy SVA-Potsdam (Potsdam Model Basin)

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 56

Marine: Sensor Design 57

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 61

Thanks You! Questions? marshall.loewenstein@ansys.com Ian.lockley@ansys.com 62