CENTAUR Laboratory Test Facility
In order to test the control hardware and algorithm developed for the CENTAUR project a laboratory facility has been constructed. The CENTAUR laboratory facility, as shown in Figure 1, is at full scale and consists of a 30 m long, 0.2 m diameter ‘sewer’ pipe with four manholes which are 1.5 m high and 1 m in diameter. Water is fed into the system at manhole 1 (MH1) via a pair of submersible pumps capable of a combined output flow of 50 l/s, with the flow rate controlled by butterfly valves after each pump. A further butterfly valve, at the downstream end of the 0.2m diameter “sewer” pipe controls the water level. The flow control device (FCD), installed in the third manhole (MH3) is based on a Steinhardt ElectroSlide of 0.2 m in diameter. The final manhole (MH4) represents the flooding location, in the laboratory test facility this doesn't actually flood, however the aim of testing is to control water levels in this manhole.
The facility is instrumented with pressure transducers which measure water levels at two locations. The first pressure transducer is in the third (control) manhole upstream of the FCD (MH3) and the second is in the fourth (flood location) manhole (MH4). Water level data is collected at 10 second intervals (0.1 Hz) and this is input to the Fuzzy Logic based control algorithm every 60 seconds. The video at the bottom of this page shows the ElectroSlide FCD operating due to a control signal from the CENTAUR algorithm.
The laboratory testing undertaken so far involves mimicking a rainfall event by increasing water levels over time, then reducing them back to the normal level. Results of this testing have shown that the CENTAUR algorithm is able to reduce water levels at the ‘flood location’ (MH4) by reducing the FCD opening in order to store water in the upstream pipes and manholes. Figure 2 shows results of one of these tests, the baseline test (solid lines) is with the FCD inactive and fully open, the CENTAUR test (open circle points) is with the FCD active (i.e. controlled by the CENTAUR algorithm). In Figure 2 it can be seen that in the baseline test the water levels at the 'flood location' and upstream of the FCD follow a similar pattern with an offset between them. The FCD remains fully open. In the CENTAUR controlled case, the FCD starts to close after around 12 minutes, this results in water levels upstream of the FCD increasing more quickly than in the baseline case because less water is passing to the downstream network. As a result water levels at the 'flood location' stop rising and the peak water level at the 'flood location' is over 30 cm lower than in the baseline case. After the ‘rainfall event’, water levels at the flood location decrease back to normal levels and the FCD re-opens gradually allowing the stored water to be released, until at around 46 minutes the water levels are back to normal and the FCD re-opens fully.