Reynolds Experiment
This experiment replicates the work done by Osborne Reynolds to characterize laminar
and turbulent flow in terms of the “Reynolds Number” (ρvD/µ). The Reynolds apparatus
allows the experimenter to visualize the flow and determine whether it is laminar,
transitional, or turbulent. An overflow tank maintains a constant pressure head on the
flow tube while flow rate is controlled via the globe valve at the outlet. Die is injected
into the bell mouth at the flow tube in order to visualize the flow. Flow rates (and
therefore average flow velocity, v) may be determined by determined by collecting the
liquid in a graduated cylinder at the outlet, and recording the time it takes to fill a given
volume. The apparatus should be leveled prior to beginning the experiment.
Assignment:
Run the experiment at flows that increase from well below the theoretical transition flow
rate, increasing all the way through fully developed turbulent flow. Observe carefully the
dye stream to ascertain the character of the flow and report your observations. Compare
your results to the accepted values for laminar, transitional, and turbulent pipe flow. You
may need to experiment to find the optimum flow rate for the dye. Describe how you
determined optimum operating conditions and what they were. Describe your
experimental method. Was the degree of turbulence dependant only upon flow rate?