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PLUMBING CONNECTION
SUMMER 2016
events from around the world. The pumps are capable of
delivering 100 litres per second, which far exceeds the
maximum flow of 16 litres per second as set out in the
Australian Standard for box gutter design.
“When dealing with such high circulation flows (100 l/s)
uncontrolled wave generation within the tank can cause
cavitation and subsequent failure of the pumps,” Mark
explains.
“To counter this possibility, Terry and the team at
USC developed a simple but effective anti-wave baffle
constructed from a modified concrete stormwater pipe. This
is another demonstration of Dr Terry Lucke’s experience in
being able to implement a simple and reliable solution to a
complex problem. Terry’s ability in this regard has enabled
the overall costs of the Research Project to be much lower
than they would have been if we were working with a less
experienced team.”
The initial flow modelling results have already revealed
some remarkable results that will change the way the industry
think about roof drainage solutions. The development of
combination hybrid systems (gravity/syphonic) is one of the
advanced design solutions under review.
Having the ability to test and witness all the components
of the roof drainage system in concert (gutters, sumps,
overflow, outlets, downpipes) has provided the team with
a unique opportunity to observe and record the important
hydraulic relationship that one component of the system
has with another. This unique aspect of the AHSCA Research
Facility will assist in a better understanding of the hydraulic
characteristics that has not been possible in previous studies.
The Research Facility is also able to review and verify
currently available data that is included in various
references such as AS/NZS 3500.3. This provides the
opportunity for the research team to reverse engineer
current sizing guidelines to identify excessive safety
allowances (in addition to freeboard). Identification of
duplicated safety allowances will result in more realistic and
efficient outcomes for AHSCA members.
While the vast majority of the rig is completed and
commissioned, the research team is still developing one of
the extremely important and sensitive areas. A multitude
of measuring and recording devices has been trialled using
various technologies and the team is currently reviewing
the trial results of the various systems with the full
implementation and commissioning due in the upcoming
months.
Dr Terry Lucke also designed an oversized return flow
gutter at the base of the test rig that allows observations
of localised turbulent discharges from downpipes. This
type of configuration may be used where upper catchments
discharge to lower gutters. This addition to the rig allows
the opportunity for future research and the development of
further design solutions.
AHSCA UPDATE
The test rig is impressive across the board and uses pumps
that are capable of delivering 100 litres per second.
“The return gutter also allows the observation of the
discharge flows from positive and negative pressure
environments at various flow rates. This will allow us to
development the most suitable connections of the roof
drainage systems to the in ground stormwater networks.
“The additional mid and lower working levels originally
incorporated into the design in the test rig by Dr Terry
Lucke has allowed additional research to be undertaken