A Mariotte bottle is a device that provides a constant effusion velocity for liquids. We discuss a Mariotte bottle that has been designed to study the flow regime and the transition from laminar to turbulent flow. Several straight, smooth, circular glass tubes with different lengths and sections were inserted into the lower part of the bottle so that the rate of flow could be measured in very different experimental conditions by using a precision balance. Reynolds numbers in the interval 1014less than or equal toR less than or equal to6098 were obtained, showing that the flow regime is laminar for Rless than or equal to3000. There is a transition in the flow regime for R in the interval 3000-4000 and a turbulent flow regime for higher R. Because the device is very simple and the results obtained are very clear and exemplary, we recommend using this device as a laboratory experiment for physics or engineering students who require a knowledge of fluid mechanics. (C) 2002 American Association of Physics Teachers. [References: 7]
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