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Improving Hydrodynamic Efficiency through Active and Passive Flow Control. Harrison DiGia Advanced Science Research Period 7. Need. 843 million tons of CO 2 were released by international shipping in 2007 (International Maritime Organization)
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Improving Hydrodynamic Efficiency through Active and Passive Flow Control Harrison DiGia Advanced Science Research Period 7
Need • 843 million tons of CO2 were released by international shipping in 2007 (International Maritime Organization) • Reducing the friction and the drag on a ship's hull could improve efficiency by up to 20% Maritime Research Institute Netherlands (MARIN) • 90% of all goods that were sent around the globe went by ship (Kodama, 2006)
Active vs. Passive Flow Control • Passive Flow Control- No energy is necessary to modify flow • Active Flow Control- Energy is necessary http://drp2010.googlepages.com/golfballairflow.jpg http://gtresearchnews.gatech.edu/images/truckfuel1_md.jpg
Bulbous Bow • Protrudes just below the waterline • Modifies flow • Ideal for large ships http://www.globalsecurity.org/military/systems/ship/images/bulbous-bow-image08.jpg
The Effect of the Bulbous Bow http://www.globalsecurity.org/military/systems/ship/images/bulbous-bow-image08.jpg
Micro-Bubbles http://www.newscientist.com/data/images/archive/2539/25391601.jpg
Literature Review • Madavan et al., (1984)- Used porous plates to create bubbles • Kodama et al., (2000)- Performed micro-bubble experiments in a water tunnel • McCormick and Bhattchara (1973)- Used electrolysis to produce micro-bubbles • Yoshido (1998)- Used model ship and showed a 10% decrease in drag
Do-ability • Water tunnel in lab • Software for active flow control can be designed • Boat is already made • Micro-bubbles can be created using a simple aquarium bubbler • Bulbous bow can easily be inserted into front of model ship
Purpose • Combine active and passive flow control techniques and examine the effect on drag
Bibliography • Culley, Dennis. "Active Flow Control Laboratory." NASA - Active Flow Control. NASA. 29 Feb. 2008 <http://www.grc.nasa.gov/cdtb/facilities/flowcontrollab.html>. • Donovan, John, and Linda Kral. "Active Flow Control Applied to an Airfoil." American Institute of Aeronautics (1998). • Liou, William W. Microfluid mechanics. New York: McGraw-Hill, 2005. • Lraub, Lance. "Laminar to Turbulant Flow Control, Research,." Morpheus Laboratory, University of Maryland. Jan. 2004. <http://www.morpheus.umd.edu/research/active-flow-control/flapping-flow.html>. • Marchaj, C.A. Aero-Hydrodnamics of Sailing. Camden: International Marine, 1991. • Pike, John. "Bulbous Bow." Global Security. 7 Oct. 2006. <http://www.globalsecurity.org>. • Scott, Jeff. "Leading Edge Extensions." Aerospaceweb.org | Reference for Aviation, Space, Design, and Engineering. 16 May 2004. <http://www.aerospaceweb.org/question/planes/q0176.shtml>. • Scott, Jeff. "Vortex Generators." Aerospaceweb.org | Reference for Aviation, Space, Design, and Engineering. 14 Jan. 2001. <http://www.aerospaceweb.org/question/aerodynamics/q0009.shtml>. • Washington University in St. Louis (2009, March 18). Engineer Devises Ways To Improve Gas Mileage. ScienceDaily