Manly Hydraulics Laboratory Irrigation Testing Facility

Manly Hydraulics Laboratory Irrigation Testing Facility

An irrigation testing facility has been constructed at MHL to test irrigation flowmeters in flow conditions as near as possible to those in the field. The rig, developed as part of the Know the Flow project, allows testing of complete flow measurement installations over a range of conditions. These include the common irrigation arrangement where the flowmeter is installed in a pipe draining from an open supply channel. This is in contrast to the usual method of testing flowmeters in a pipe rig where these field approach conditions cannot be simulated. Typical testing can include evaluation of the accuracy of installations and their sensitivity to the various adverse flow conditions that occur in the field and headloss measurements over a range of flows.

The facility comprises a regulated water supply, two electromagnetic flowmeters, an upstream head box, a test area and drainage system. The layout of the rig is shown in the images below. One side of the head box is constructed from marine plywood to allow either open channel or piped flow measurement systems to be easily installed for testing. The general specifications of the rig are:--

Water Supply Gravity pipelines from Manly Dam. 10m head. Total available flowrate more than 25ML/day.
Flow Measurement Two electromagnetic flowmeters, flowrate and totaliser display, NATA calibrated. Measurement of uncertainty 0.25% of measured quantity or 60L. In-situ calibration verification system fitted.
Head Box Above ground, 7.2m x 6.0m x 1.2m. Mechanical water level follower reading to 0.1mm.
Test Area 8.0m x 6.0m. Longer installations can also be accommodated.
Drainage Below ground channel to waste or to 2 x 0.8ML volumetric tanks

A range of approach conditions, such as flow across an intake or eddy shedding from abrupt changes in geometry, can be simulated by arranging baffles in the head box. Piped flow systems requiring more than 1.2m of head can be tested using other facilities at the Laboratory.

Currently a Dethridge emplacement is installed in the test area to enable testing of devices inserted either in the emplacement or immediately upstream or downstream, however the test area is sufficiently wide to enable other devices to be installed in parallel.

Some Views of the Test Rig


A schematic view of the flow test rig.	A general view of the flow test rig.	A close-up view of the test section.	A close-up view of the head box and test section.

For inquires about this facility contact:--
Manly Hydraulics Laboratory
110b King Street
MANLY VALE 2093
SYDNEY
AUSTRALIA

Telephone Number : + 61 2 99490200
Facsimile Number : + 61 2 99486185
Contact Bob Cook : RCook@mhl.nsw.gov.au

Water Supply	Gravity pipelines from Manly Dam. 10m head. Total available flowrate more than 25ML/day.
Flow Measurement	Two electromagnetic flowmeters, flowrate and totaliser display, NATA calibrated. Measurement of uncertainty 0.25% of measured quantity or 60L. In-situ calibration verification system fitted.
Head Box	Above ground, 7.2m x 6.0m x 1.2m. Mechanical water level follower reading to 0.1mm.
Test Area	8.0m x 6.0m. Longer installations can also be accommodated.
Drainage	Below ground channel to waste or to 2 x 0.8ML volumetric tanks