ocen 671 ocean wave mechanics · • text: water wave mechanics for engineers and scientists, r.g....
TRANSCRIPT
Your Host • Instructor: Dr. James M. Kaihatu
– CE/TTI 808D – Ph: 979-862-3511; email:
[email protected] – Office hours: MW 1400-1600
– Ph.D. University of Delaware 1994 – 1987-1989: Coastal Engineering
Research Center – 1994-2006: Naval Research
Laboratory (DC & MS) – 2006-present: Zachry Department
of Civil Engineering, Texas A&M University
Bordeaux the Mutt, with her minion
Why Study Ocean Wave Mechanics?
• Engineers – Levee Design! – Offshore platform
design – Dredging – Coastal structures and
harbor design – Beach erosion
mitigation – Sewage outfall design – Boating and watercraft
design – etcetcetc
Levee break at Inner Harbor Navigational Canal, New Orleans, LA
Why Study Ocean Wave Mechanics?
• Geologists – River delta formation
and evolution – Stratigraphy – Beach erosion and
shoreline change – Cliff erosion – Sediment supply – Tidal inlets – Etcetcetc…
Mississippi River Delta
Why Study Ocean Wave Mechanics?
• Planners – Prediction of
hazardous conditions – Navigation – Development control – Ship routing – Berthing – Military concerns – Etcetcetc.
Forecast of waveheights in the global ocean
OCEN671 • MWF 9:10-10:00, CVLB115 • Office hours: 1400-1600 MW; please make advance
arrangements for different time • Pre-requisite: OCEN362 or equivalent • Text: Water Wave Mechanics for Engineers and
Scientists, R.G. Dean and R.A. Dalrymple (1984 Prentice-Hall; 1989 World Scientific)
• Will deviate from text with notes, particularly in mathematical development, but will follow topic order of book
• Individual subtopics within chapters may be adjusted depending on progress of class or nature of material
• Mid-term: 30%; final exam: 40%; homework: 30%
OCEN671
• Notes are available: – http://ceprofs.civil.tamu.edu/jkaihatu – Follow links to .pdf files – Do not worry about section numbers in notes – Please ask if writing is illegible… – The password is……
OCEN671
• Optional additional reference texts: – Applied Dynamics of Ocean Surface Waves, C.C. Mei, Wiley-
Interscience 1983; World Scientific 199? – The Dynamics of the Upper Ocean, O.M. Phillips, Cambridge
University Press 1980. – Wind Waves, B. Kinsman, Dover 1984. – Water Waves, J.J. Stoker, Interscience 1957. – Waves in the Ocean, P. LeBlond and L. Mysak, Elsevier 1978. – Coastal Engineering Manual, U.S. Army Corps of Engineers,
available online at: http://chl.erdc.usace.army.mil/chl.aspx?p=s&a=ARTICLES;104 (Part 2 – Chapter 1 recommended)
OCEN671
• Homework given out after completion of each chapter
• Homework is due at the end of class on due date – 10% penalty each day (not class) it is late
except for University-recognized excuse • Prior notification must be given, except when this
is not possible (emergencies, etc.) • Email notification is acceptable
OCEN671
• Exams: – Mid-term: October 12 (tentative)
• Take home –due back Oct 14
– Final: December 12 • 8:00-10:00 am
– Time conflicts can be reasonably accommodated with advance notice.
Ocean Waves – An Introduction
• Ocean waves: subset of waves in fluids • Waves occur at any interface between
fluids of two densities • Atmospheric wave above (Iowa)
Ocean Waves – An Introduction
• What causes waves on the ocean?
Wind Ships
Undersea Earthquakes Um…Miscellanous
Ocean Waves – An Introduction
• Ocean waves are inherently nonlinear
Waves in the ocean of different frequencies affect each other (interact)
Ocean Waves – An Introduction
• Ocean waves are inherently random
Waves of many different frequencies and directions exist in the ocean
Ocean Waves – An Introduction
In this course: assume waves are linear • Waves of different frequencies and
directions do not interact • Random wave fields are built up from
superposition
At first: assume waves are monochromatic • Waves defined by a single
frequency and direction • Useful for studying details
of wave kinematics and dynamics
Ocean Waves – An Introduction
Ocean waves are dispersive – waves travel at speeds dependent on their frequencies
Ocean Waves – An Introduction
Ocean waves have many different scales
Course Content • Review of Mathematics and Fluid Mechanics
– Potential Function, Stream Function, Bernoulli Equation – Kinematic and Dynamic Boundary Conditions
• Water Wave Problem – Formulation – Linearization
• Kinematics and Dynamics – Phase speed, group speed, pressure field – Internal velocities, wave energy
• Transformation – Refraction, diffraction, shoaling – Wave breaking – Numerical modeling
Course Content • Long Waves
– Tides, Seiches, Storm Surge
• Wavemakers – Flap – Paddle – Directional wavemakers
• Random Waves – Wave statistics – Wave spectra, directional spectra, parameterized spectra
• Nonlinear Properties of Linear Waves – Mass flux, momentum flux – Radiation stress – Wave setdown, wave setup
• Introduction to Nonlinear Waves – Stokes waves – Cnoidal waves
Recommended Video
• “Waves Across the Pacific” – Various forms on YouTube – Narrator and lead researcher: Dr. Walter
Munk, Scripps Institute of Oceanography – Covers wind wave generation, dispersion,
swell propagation, wave measurement…