Osborne-Reynolds Apparatus

The apparatus consists of a precision-bore glass pipe (test
tube) held vertically in a large shroud. The shroud is open
at the front and the inside surface is light coloured. This
allows the students to see the flow clearly.
Water enters a constant head tank (reservoir) above the
test tube and passes through a diffuser and stilling bed. It
then passes through a specially shaped bell-mouth into the
test tube. This arrangement ensures a steady, uniform flow
at entry to the test tube. A thermometer measures the
temperature in the constant head reservoir.
A fixed overflow pipe in the reservoir connects to a suitable
drain. At the bottom of the test pipe is a valve which
controls the flow rate through the pipe, without disturbing
the flow.
Students collect a known quantity of water in a measured
time to find the flow rate. Included is a measuring cylinder.
To see the pattern of flow in the pipe, students use a dye
injector (included). They use it to inject a fine filament of
dye into the top of the tube. The dye injector is a dye
reservoir connected to a fine hypodermic tube.
The base of the apparatus has adjustable feet for levelling
prior to use (included is a levelling device).
The optional Heater Module (H215a) is a separate freestanding
unit. It connects to the water supply line to heat
the water, varying its temperature and viscosity. Controls
on the module vary the electrical heat input and the flow
rate, to give steady conditions over a range of
temperatures.