Improving Hydrodynamic Efficiency through Active and Passive Flow Control
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)
Improving Hydrodynamic Efficiency through Active and Passive Flow Control
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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