A water tunnel is an experimental facility used for testing the hydrodynamic behavior of submerged bodies in flowing water. It functions similar to a recirculating wind tunnel, but uses water as the working fluid, and related phenomena are investigated, such as measuring the forces on scale models of submarines or lift and drag on hydrofoils. Water tunnels are sometimes used in place of wind tunnels to perform measurements because techniques like particle image velocimetry (PIV) are easier to implement in water. For many cases as long as the Reynolds number is equivalent, the results are valid, whether a submerged water vehicle model is tested in air or an aerial vehicle is tested in water. For low Reynolds number flows, tunnels can be made to run oil instead of water. The advantage is that the increased viscosity will allow the flow to be a higher speed (and thus easier to maintain in a stable manner) for a lower Reynolds number.
Cavitation tunnel of the Versuchsanstalt für Wasserbau und Schiffbau in Berlin
Whereas in wind tunnels the driving force is usually sophisticated multiblade propellers with adjustable blade pitch, in water and oil tunnels the fluid is circulated with pumps, effectively using a net pressure head difference to move the fluid rather than imparting momentum on it directly. Thus the return section of water and oil tunnels does not need any flow management; typically it is just a pipe sized for the pump and desired flow speeds. The upstream section of a water tunnels generally consists of a pipe (outlet from the pump) with several holes along its side and with the end open followed by a series of coarse and fine screens to even the flow before the contraction into the test section. Wind tunnels may also have screens before the contraction, but in water tunnels they may be as fine as the screen used in window openings and screen doors.
Additionally, many water tunnels are sealed and can reduce or increase the internal static pressure, to perform cavitation studies. These are referred to as cavitation tunnels.
Cavitating propeller model in 'David Taylor Model Basin'
Because it is a high-speed phenomenon, a special procedure is needed to visualize cavitation. The propeller, attached to a dynamometer, is placed in the inflow, and its thrust and torque is measured at different ratios of propeller speed (number of revolutions) to inflow velocity. A stroboscope synchronized with the propeller speed "freezes" the cavitation bubble. By this means, it is possible to determine if the propeller would be damaged by cavitation. To ensure similarity to the full-scale propeller, the pressure is lowered, and the gas content of the water is controlled.
Often, a tunnel will be co-located with other experimental facilities such as a wave flume at a Ship model basin.
"Grand Tunnel Hydrodynamique" Bassin d'Essais des Carènes,[4] Val de Reuil
"TH8.2V : Tunnels Hydrodynamiques 8 ou 2 m3/s"[5] Centre d'études et de recherche de Grenoble
Germanyedit
Multiple cavitation tunnels at the Versuchsanstalt für Wasserbau und Schiffbau,[6] Berlin
Cavitation tunnel at the University Duisburg-Essen, Institute of Ship Technology, Ocean Engineering and Transport Systems,[7] University Duisburg-Essen
Cavitation tunnel at Potsdam Ship Model Basin,[8] Potsdam
Large Cavitation tunnel at Hamburg Ship Model Basin,[9] Hamburg
Multiple cavitation tunnels at the Oskar von Miller Institut,[10] Technical University of Munich
^"Home". Australian Maritime College - University of Tasmania, Australia. Retrieved 2018-09-30.
^Canada, Government of Canada. National Research Council. "Cavitation Tunnel - National Research Council Canada". www.nrc-cnrc.gc.ca. Retrieved 2018-09-30.
^"Accueil | Ecole Navale". www.ecole-navale.fr (in French). Retrieved 2018-09-30.
^Large Cavitation Channel (LCC) 2007-08-07 at the Wayback Machine
^. The William States Lee College of Engineering. June 1, 2009. Archived from the original on July 28, 2017.
External linksedit
Wikimedia Commons has media related to Water tunnels (scientific equipment).
"Under Water Speed Way..." Popular Mechanics, July 1949
Description of a commercial water tunnel showing the inlet baffle, flow conditioning screens, and converging section.
These show the clear difference between a recirculating wind tunnel and a water tunnel.
A miniature water tunnel whose return section is simply a reservoir tub with a sump pump. Flow rate is controlled by constricting the flow on the outlet of the pump with a valve.
January 01, 1970
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A water tunnel is an experimental facility used for testing the hydrodynamic behavior of submerged bodies in flowing water It functions similar to a recirculating wind tunnel but uses water as the working fluid and related phenomena are investigated such as measuring the forces on scale models of submarines or lift and drag on hydrofoils Water tunnels are sometimes used in place of wind tunnels to perform measurements because techniques like particle image velocimetry PIV are easier to implement in water For many cases as long as the Reynolds number is equivalent the results are valid whether a submerged water vehicle model is tested in air or an aerial vehicle is tested in water For low Reynolds number flows tunnels can be made to run oil instead of water The advantage is that the increased viscosity will allow the flow to be a higher speed and thus easier to maintain in a stable manner for a lower Reynolds number Cavitation tunnel of the Versuchsanstalt fur Wasserbau und Schiffbau in Berlin Whereas in wind tunnels the driving force is usually sophisticated multiblade propellers with adjustable blade pitch in water and oil tunnels the fluid is circulated with pumps effectively using a net pressure head difference to move the fluid rather than imparting momentum on it directly Thus the return section of water and oil tunnels does not need any flow management typically it is just a pipe sized for the pump and desired flow speeds The upstream section of a water tunnels generally consists of a pipe outlet from the pump with several holes along its side and with the end open followed by a series of coarse and fine screens to even the flow before the contraction into the test section Wind tunnels may also have screens before the contraction but in water tunnels they may be as fine as the screen used in window openings and screen doors Additionally many water tunnels are sealed and can reduce or increase the internal static pressure to perform cavitation studies These are referred to as cavitation tunnels Cavitating propeller model in David Taylor Model Basin Contents 1 Methods 2 List of water tunnels cavitation tunnels 2 1 Australia 2 2 Brazil 2 3 Canada 2 4 France 2 5 Germany 2 6 India 2 7 Iran 2 8 Italy 2 9 The Netherlands 2 10 Norway 2 11 Spain 2 12 Serbia 2 13 Switzerland 2 14 Taiwan 2 15 Turkey 2 16 United Kingdom 2 17 United States 3 See also 4 References 5 External linksMethods editBecause it is a high speed phenomenon a special procedure is needed to visualize cavitation The propeller attached to a dynamometer is placed in the inflow and its thrust and torque is measured at different ratios of propeller speed number of revolutions to inflow velocity A stroboscope synchronized with the propeller speed freezes the cavitation bubble By this means it is possible to determine if the propeller would be damaged by cavitation To ensure similarity to the full scale propeller the pressure is lowered and the gas content of the water is controlled Often a tunnel will be co located with other experimental facilities such as a wave flume at a Ship model basin List of water tunnels cavitation tunnels editAustralia edit Australian Maritime College AMC 1 Brazil edit Laboratory of Naval and Oceanic Engineering NAVAL Institute for Technological Research IPT of Sao Paulo Canada edit National Research Council Institute for Ocean Technology Cavitation Tunnel 2 St John s Newfoundland France edit Tunnel de Cavitation Ecole Navale 3 Lanveoc Grand Tunnel Hydrodynamique Bassin d Essais des Carenes 4 Val de Reuil TH8 2V Tunnels Hydrodynamiques 8 ou 2 m3 s 5 Centre d etudes et de recherche de Grenoble Germany edit Multiple cavitation tunnels at the Versuchsanstalt fur Wasserbau und Schiffbau 6 Berlin Cavitation tunnel at the University Duisburg Essen Institute of Ship Technology Ocean Engineering and Transport Systems 7 University Duisburg Essen Cavitation tunnel at Potsdam Ship Model Basin 8 Potsdam Large Cavitation tunnel at Hamburg Ship Model Basin 9 Hamburg Multiple cavitation tunnels at the Oskar von Miller Institut 10 Technical University of Munich India edit Fluid Control Research Institute Palakkad Kerala Cavitation Tunnel of the Naval Science and Technology Labs at Visakhapatnam Department of Aerospace Engineering Indian Institute of Technology Kharagpur Indian Institute of Technology Madras Iran edit Applied Hydrodynamics Laboratory Iran University of Science and Technology 11 Narmak Tehran Marine Engineering Laboratory Sharif University of Technology 12 13 Azadi Av Tehran Italy edit Department of Naval Architecture University of Genoa INSEAN Cavitation facility INSEAN National Institute of Studies and Experiments in Naval Architecture Rome The Netherlands edit Large Cavitation Tunnel and High Speed Cavitation Tunnel at Maritime Research Institute Netherlands in Wageningen Twente Water Tunnel facility at University of Twente 14 Norway edit Cavitation Lab NTNU The Norwegian University of Science and Technology Trondheim Spain edit CEHIPAR Canal de Experiencias Hidrodinamicas de El Pardo 4 El Pardo Madrid Spain Serbia edit The Large Cavitation Tunnel at Military Technical Institute Belgrade Serbia Switzerland edit High Speed Cavitation Tunnel at LMH Lab of Hydraulic Machines EPFL Ecole Polytechnique Federale de Lausanne Switzerland Taiwan edit Large Cavitation Tunnel at National Taiwan Ocean University 國立臺灣海洋大學 15 from Zhongzheng Keelung Taiwan Large Cavitation Tunnel at National Cheng Kung University 國立成功大學 16 from East Tainan Taiwan Large Cavitation Tunnel at National Taiwan University 國立臺灣大學 17 from Da an Taipei Taiwan also look at sea transportation in Taiwan Large Cavitation Tunnel at National Kaohsiung Marine University 國立高雄海洋科技大學 from Nanzih Kaohsiung Taiwan Turkey edit ITU Cavitation Tunnel at Istanbul Technical University Turkey 18 United Kingdom edit Emerson Cavitation Tunnel University of Newcastle upon Tyne 19 United States edit The Garfield Thomas Water Tunnel The Pennsylvania State University 20 State College PA The William B Morgan Large Cavitation Channel 21 Memphis TN David Taylor Model Basin Carderock Division of the Naval Surface Warfare Center Water Tunnel The University of North Carolina at Charlotte 22 Charlotte NCSee also editWave tank Wind tunnelReferences edit Home Australian Maritime College University of Tasmania Australia Retrieved 2018 09 30 Canada Government of Canada National Research Council Cavitation Tunnel National Research Council Canada www nrc cnrc gc ca Retrieved 2018 09 30 Accueil Ecole Navale www ecole navale fr in French Retrieved 2018 09 30 cadre Archived 2006 02 10 at the Wayback Machine Tunnels Hydrodynamiques 8 ou 2 m s www cerg lab com Retrieved 2016 04 08 Test Facilities Archived from the original on May 3 2008 Cavitation Tunnel www uni due de Retrieved 2018 09 30 SVA Schiffbau Versuchsanstalt Potsdam www sva potsdam de in German Retrieved 2018 09 30 Conventional Cavitation Tunnels www hsva de in German Retrieved 2018 09 30 TUM Lehrstuhl und Versuchsanstalt fur Wasserbau und Wasserwirtschaft Infrastruktur der Versuchsanstalt Obernach in German Archived from the original on February 26 2012 1 Archived April 9 2010 at the Wayback Machine 2 Archived November 13 2007 at the Wayback Machine 3 Archived August 23 2007 at the Wayback Machine Physics of Fluids Research Facilities Twente Water Tunnel pof tnw utwente nl Retrieved 2018 09 30 NTOU Systems Engineering and Naval Architecture Research Center www se ntou edu tw Retrieved 2018 09 30 University unveils naval test facility Taipei Times www taipeitimes com 27 September 2002 Retrieved 2018 09 30 University unveils naval test facility Taipei Times www taipeitimes com 27 September 2002 Retrieved 2018 09 30 ITU de kavitasyon tuneli acildi CNN Turk in Turkish 17 December 2021 Emerson Cavitation Tunnel Engineering School of Newcastle University www ncl ac uk Archived from the original on 2018 09 30 Retrieved 2018 09 30 GTWT Archived 2006 05 21 at the Wayback Machine Large Cavitation Channel LCC Archived 2007 08 07 at the Wayback Machine Water Tunnel The William States Lee College of Engineering June 1 2009 Archived from the original on July 28 2017 External links edit nbsp Wikimedia Commons has media related to Water tunnels scientific equipment Under Water Speed Way Popular Mechanics July 1949 Description of a commercial water tunnel showing the inlet baffle flow conditioning screens and converging section These show the clear difference between a recirculating wind tunnel and a water tunnel A miniature water tunnel whose return section is simply a reservoir tub with a sump pump Flow rate is controlled by constricting the flow on the outlet of the pump with a valve Retrieved from https en wikipedia org w index php title Water tunnel hydrodynamic amp oldid 1218525527, wikipedia, wiki, book, books, library,
