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Reynolds Number

In 1883, Osborne Reynolds expanded the results of the experiments of Darcy and defined the ``critical velocity''. Darcy's experiments were based on laminar flow, the movement of fluid essentially in parallel lines when viewed on a macroscopic scale. Critical velocity defines the transition between laminar flow and turbulent flow where fluid moves in irregular and rotational paths. This transitional velocity is a dimensionless ratio named the Reynolds number and defines a range for the validity of Darcy's Law in turbulent flow. (Appendix B)

If the value of the Reynolds number, RE is:

 ¯  Darcy's Law is valid

partially turbulent flow exists

Darcy's Law does not hold

turbulent flow

Darcy's Law does not hold



Rhonda Macleod
Mon Apr 17 16:32:58 EDT 1995