Demonstrations

Laminar and Turbulent Flow Demos

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Code Number :	2C40.50
Disclaimer:	Reprinted by permission of Dick Berg, University of Maryland, for use on this website. The demonstrations contained and referenced herein are listed for the purposes of cataloging and describing physics demonstrations which should be conducted only under the direction of a trained instructional support professional or physicist. These demonstrations are not presented for the purpose of being conducted by persons unconnected to this Facility and/or persons not consulting with or being supervised by the recognized instructional support professional or physicist and his/her staff. The University is responsible only for those demonstrations carried out using its own equipment using established safety and scheduling policies, and bears no responsibility for those choosing to use this source material for their own purposes. All demonstrations described and contained herein are public domain, and can also be found in reference materials in libraries, bookstores, and electronic sources. Further information regarding legal liability in use of demonstrations and labs will be found on the web site Injuries in School/College Laboratories in USA. The University of Iowa Disclaimers: University of Iowa Disclaimer All Rights Reserved..
Condition :	Fair
Principle :	Flow Rates of Liquids, Viscosities
Area of Study :	Heat and Fluids
Equipment :	5 gallon bucket with holes in bottom, Stainless steel tubes with stoppers, Meter Stick, Stop Watch, Large Plastic Beakers, Graduated Cylinders, Large Plexiglas Splash Tank, Tube Assembly (Two tubes whose ratio of diameters is 1 to 2), Rheoscopic Fluid, Fish Tank and Fluorescein dyed water, Funnel and tygon tube with eyedropper nozzle, Pinpoint light source with power supply, Dewar Flask, Insulated gloves, Fish tank accessory mount for nozzle.
Procedure :	Laminar Flow: Insert the desired tubes into the 5 gallon bucket. Fill the bucket to a measure water height. While timing with a stopwatch unplug the ends of the tubes and catch the water from each tube in a separate graduated cylinder. At a desired time interval remove the graduated cylinders from each tube and measure the amount of water in each. The results from one of these experiments is enclosed with the calculations and a calculation of the errors as they deviate from theoretical. Set the splash tank on the lecture bench with the drain hole over the lecture bench sink. Raise the tubes to a height where the water flow drops straight down when set at a certain flow rate. As the diameters of the tubes are a ratio of 1 to 2, the distance each water jet falls from the end of the tubes should be in a ratio of 1 to 4. (Increase the diameter by 2 and increase the flow rate by 4). Basically this method uses changes in refractive index to cast a shadow on the screen of the laminar and turbulent flow regions. Shine the pinpoint light source through the tank, at the nozzle and onto a screen behind the tank. Pointing the light upward through the tank will allow you to see the shadowgraph above tank height on the screen. A piece of masking tape along the top water level of the tank will eliminate the internal reflection from the top surface. The height difference between the funnel and the nozzle determines flow velocity. Using water that is hotter or colder than the tank water temperature determines whether the turbulent regions flow upward or sink. The Dewar is for carrying the hot or cold water. A VERY DRAMATIC DEMO!! The Rheoscopic fluid will very easily show planes of shear fluid dynamics. Hand soap that has glycerol stearate in it will also show nice flow patterns when mixed with water. Glycerol distearate does not work as well.

References

Richard Humbert, "Water Nozzles", TPT, Vol. 43, # 9, Dec. 2005, p. 604.

Stephen J. Hook and Michael F. Schatz, "Simple Demonstrations of Pattern Formation," TPT, Vol. 35, # 7, p. 391- 395, (Oct. 1997).

Volker Thomsen, "Estimating Reynolds Number in the Kitchen Sink", TPT, Vol. 31, # 7, Oct. 1993, p. 410.

Richard M. Heavers, "Submerged Horizontal Jets in Water", TPT, Vol. 30, # 7, Oct. 1992, p. 423.

Dean O. Kuethe, "Confusion About Pressure", TPT, Vol. 29, # 1, Jan. 1991, p. 20.

Richard M. Heavers and Maria G. Medeiros, "Laminar and Turbulent Flow in a Glass Tube," TPT, Vol. 28, # 5, p. 297, (May 1990).

J. A. Maroto, J. de Dois, F. J. de las Nieves, "Use of a Mariotte Bottle for the Experimental Study of the Transition From Laminar to Turbulent Flow", AJP, Vol. 70, # 7, July 2002, p. 698.

Yakov Afanasyev, "Investigating Vortical Dipolar Flows Using Particle Image Velocimetry: An Experiment for the Advanced Undergraduate Laboratory", AJP, Vol. 70, # 1, Jan. 2002, p. 86

F- 290: "Flow Rate vs. Tube Radius", DICK and RAE Physics Demo Notebook

Fk - 3: Freier and Anderson, A Demonstration Handbook for Physics.

William F. Vinen, and Russell J. Donnelly, "Quantum Turbulence", Physics Today, April 2007, p. 43.

Gregory Falkovich and Katepalli R. Screenivasan, "Lessons from Hydrodynamic Turbulence", Physics Today, April 2006, p. 43.

Charles Day, "Laser Technique Follows Turbulent Flow in Three Dimensions," Physics Today, March 2003.

Richard Fitzgerald, "New Experiments Set the Scale for the Onset of Turbulence in Pipe Flow", Physics Today, Feb. 2004, p. 21.

3.36: Jearl Walker, "Cigarette Smoke Stream," The Flying Circus of Physics with Answers.

211.30, "Laminar and Turbulent Flow Demos," Heat and Fluids Book.

Rafael M. Digilov, "Abstract: Weight-Detecting Capillary Viscometer," 2005 Apparatus Competition, Salt Lake City, UT.

J. Fluid Mech., (1980), Vol. 100, Part 3, p. 449- 470.

"Laminar and Turbulent Flow," Clouds in a Glass of Beer.

Peter Weiss, "The Physics of Flutter," How it Works - Science Supplement, Spring 2000, p. 224- 228.

Stanley J. Micklavzina, "Demonstration Ideas," PIRA Newsletter, Vol. 5, # 5, March 1991.

"Turbulent Orb," The Exploratorium Science Snackbook.

Mail Questions and Comments to: Dale Stille