Fluid Friction Measurements

Pipe friction is one of the classic laboratory experiments and has always found a place in the practical teaching of fluid mechanics.

With this unit, friction head losses in straight pipes of very different sizes can be investigated over a range of Reynolds’ numbers from 103 to nearly 105. This covers the laminar, transitional and turbulent flow regimes in smooth pipes.

In addition an artificially roughened pipe is supplied, which at the higher Reynolds’ numbers shows a clear departure from the typical smooth bore pipe characteristics. In addition to the equipment for the study of losses in straight pipes, a wide range of accessories are included such as pipe fittings and control valves, a Venturi tube, an orifice plate assembly and a Pitot tube.

An arrangement of six pipes provides facilities for testing the following:

Four smooth-bore pipes of different diameters
Artificially roughened pipe
90° bends (large & small radii)
90° elbow
90° mitre
45° elbow
45° Y
90° T
Sudden enlargement
Sudden contraction
Gate valve
Globe valve
Ball valve
Inline strainer
Perspex Venturi
Perspex orifice meter
Perspex pipe section with a Pitot tube & static tapping

Short samples of each size test pipe are provided loose so that the students can measure the exact diameter and determine the nature of the internal finish. The ratio of the pipe diameter to the distance of the pressure tappings from the ends of each pipe has been selected to minimise end and entry effects. A system of isolating valves is provided whereby the pipe to be tested can be selected without disconnecting or draining the system. This arrangement enables tests to be conducted on parallel pipe configurations.

An optional floor-standing Hydraulics Bench incorporates a sump tank and volumetric flow measurement facility. Rapid and accurate flow measurement is possible over the full working range of the apparatus.

The level rise in the measuring tank is determined by an independant sight gauge. A 250ml capacity glass measuring cylinder is supplied for measuring the flow rate under laminar conditions (very low flows).

Each pressure tapping is fitted with quick action selfsealing connection. Probe attachments with an adequate quantity of translucent polythene tubing are provided so that any pair of pressure tappings can be rapidly connected.

All the test pipes and fixed interconnecting pipes are fabricated in stainless steel.