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P. Tkalich , K.Y.H. Gin, and E.S. Chan Physical Oceanography Research Laboratory

NUMERICAL SIMULATION OF OIL SPILL COMBATING TECHNIQUES. P. Tkalich , K.Y.H. Gin, and E.S. Chan Physical Oceanography Research Laboratory Tropical Marine Science Institute The National University of Singapore. TMSI. Oil Demand in Asia-Pacific. Global Movement of Oil in 199.

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P. Tkalich , K.Y.H. Gin, and E.S. Chan Physical Oceanography Research Laboratory

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  1. NUMERICAL SIMULATION OF OIL SPILL COMBATING TECHNIQUES P. Tkalich, K.Y.H. Gin, and E.S. Chan Physical Oceanography Research Laboratory Tropical Marine Science Institute The National University of Singapore TMSI

  2. Oil Demand in Asia-Pacific

  3. Global Movement of Oil in 199 5 oil refineries in Singapore waters have total capacity over 1 mil. barrels per day. (second largest refinery area in the world, after Houston, Texas) Malacca&Singapore Straits

  4. Major Oil Spills

  5. Money spent by Exxon Corporation subsequent to EVOS (in millions of dollars) ------------------------------------------------------ Immediate Costs (1989, 19990) Cleanup $2,000 Fisherman 300 Out-of-Court Settlement (1991-2001) Damage assesment 214 Habitat protection 375 Administrative costs 35 Research, monitoring and general restoration 180 Restoration reserve 108 Accumulated interest less Court fees 12 ------------------------------------ TOTAL $3,224 Civil Trial (1995) Compensation to fishermen $287 Punitive compensation (under appeal) 5000

  6. Evoikos spill

  7. Evoikos spill

  8. Oil Properties

  9. Oil Fate wind evaporation tarballs emulsification dissolution gravitation inertia viscous interf.tension foodweb oxidation photolysis sedimentation hydrolysis biodegradation

  10. Oil Kinetics

  11. I. BOOM APPLICATION oil spill combating techniques II. CHEMICAL DISPERSANT APPLICATION top view

  12. Oil Spill Simulation Models

  13. Oil Slick Dynamics (gravity - viscosity regime) Navier-Stokes equations

  14. i-2 i-1 l i r i+1 Upstream interpolation method General form of an explicit upstream finite-difference approximation

  15. HIGH - ORDER ADVECTION APPROXIMATION USING POLYNOMIAL INTERPOLATION time space

  16. THIRD -DEGREE POLYNOMIAL: auxiliary conditions: I II Holly-Preissmann (1977) (IV-order) Leonard (1979) QUICKEST (III-order)

  17. i-2 i-1 l i r i+1 III-order QUICKEST (Leonard, 1979)

  18. Oil Transfer at Media Interfaces oil slick  oil-in-water emulsion (due to wind - waves breaking) U wave breaking h Dh Dz oil buoyancy Dh=kw(1+Sg)H Dh=0.2 g-1 kw(1+Sg)U2 Sg = r0 / rw Ce = Concentration of oil emulsion in the water column

  19. Oil Kinetics in slick h = Oil slick thickness on the water surface, m Ce = Concentration of oil emulsion in the water column, g/m3 Cd = Concentration of dissolved oil in the water column, g/m3 Cp = Particulate oil concentration in the water column, g/kg Cdb= Concentration of dissolved oil in interstitial water in the bed sediments, g/m3 Cpb = Particulate oil concentration in the bed sediments, g/kg in water column in bed sediments LOSSES: evaporation hydrolysis photolysis oxidation biodegradation

  20. Transport of the oil phases in the water column Ce = Concentration of oil emulsion in the water column, Cd = Concentration of dissolved oil in the water column, Cp = Particulate oil concentration in the water column,

  21. Oil Transfer at Media Interfaces water column - bottom layer Dz exchange coefficients water layer b bed sediments

  22. Model Parameters

  23. Comparison with data

  24. Comparison with data

  25. Oil Spill at Open Sea Channel 2-D test case oil 28,000 T U=7 m/s u=1 m/s surface fence 60 m L= 500 km

  26. 2D simulation. Oil slick thickness Dissolved oil concentration in pore water of bed sediments

  27. 2D simulation. Dissolved oil concentration in water column Emulsified oil concentration in water column

  28. BOOM-SKIMMER SYSTEM : Boom opening = 100 m Maximum Skimming rate = 150 m3/ hr Maximum operation at wave height =1 m Maximum effectiveness: (day light) = 80 % @ 5 m/s wind speed 60 % @ 10 m/s (night) = 50 % of day light values.

  29. DISPERSANT APPLICATION : Dispersant : Arcochem D-609 Oil : Dispersant Ratio = 143 : 1 Maximum dispersant effectiveness = 80 % Lethal concentration (LC50) for Zooplankton (Mysidopsis bahia) = 29 ppm (96 hrs exposure period) Spray width = 50 ft

  30. 3-D oil spill simulation at Singapore Straits

  31. Surface currents at one instant of tidal cycle for the south-west monsoon

  32. Hypothetical oil spill ~ 28,000 T in Singapore Straits Day 0

  33. Day 0.5

  34. Day 1

  35. Day 1.5

  36. Day 2

  37. Day 2.5

  38. Day 3

  39. Conclusions • The three-dimensional multiphase oil spill model is developed to simulate the consequences of accidental oil releases in the Singapore Straits. • The model is updated with a high-order numerical scheme for accurate simulation of the oil slick dynamics. • MOSM is powered with the oil combating techniques evaluation sub-module. Test simulations show a good agreement with empirical data.

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