Hydraulic Engineering
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| License | CC Attribution 4.0 International: You are free to use, adapt and copy, distribute and transmit the work or content in adapted or unchanged form for any legal purpose as long as the work is attributed to the author in the manner specified by the author or licensor. | |
| Identifiers | 10.5446/14865 (DOI) | |
| IWF Signature | C 13223 | |
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| Production Year | 2008 |
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| IWF Technical Data | Video-Clip; F, 16 min |
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00:00
Stream bedSeeschiffVolumetric flow rateHydromotorGravel pitWater vaporFahrgeschwindigkeitWater transport
00:43
Stream bedClockModel buildingCartridge (firearms)Finger protocolWater vapor
01:56
Stream bedClockVolumetric flow rateOpticsModel buildingWater vaporHull (watercraft)Reference work
02:48
Volumetric flow rateCooper (profession)Water vaporPattern (sewing)Lecture/Conference
03:38
Continuous trackVolumetric flow rateAngle of attackReference workRailroad
04:07
Stream bedModel building
04:27
Stream bedLecture/Conference
04:44
Model buildingWater vaporIntermediate bulk container
05:05
Gravel pitMaterialModel building
05:27
Model buildingCounter (furniture)
05:42
PortalkranModel buildingCounter (furniture)
05:59
Captain's gigStream bedComputer animation
06:43
Barrage (dam)Barrage (dam)
07:13
Hot workingWater vaporWater transport
07:26
Water transport
07:39
LappingStream bedSeeschiffAutomatic watchModel buildingWater vaporOptics
08:27
MachineOptics
08:46
GentlemanVolumetric flow rateModel buildingWater vaporFahrgeschwindigkeitReference workAerospace engineeringDiagram
09:19
Jig (tool)Water vaporStationeryMeeting/InterviewComputer animation
09:38
Sheet metalPressure vesselPipingModel buildingWater vapor
09:57
Lecture/Conference
10:11
Model buildingMolding (process)Engineering drawingDiagram
10:34
Rail transport operationsHot workingModel buildingWearFinger protocolWater transport
11:02
Rail transport operationsPiping
11:18
Stream bedRail profileWater vapor
11:45
SeeschiffModel buildingWater vaporKette <Zugmittel>
12:04
GentlemanKette <Zugmittel>Water vaporKopfstützeComputer animationEngineering drawing
12:18
Water vaporDyeingModel building
12:32
Kette <Zugmittel>Gas compressorPressure vesselWater vaporComputer animationEngineering drawing
12:51
Pressure vesselVolumetric flow rateWater vaporDyeing
13:06
Computer animation
13:19
Water vapor
13:37
Cartridge (firearms)Rail transport operationsModel buildingMint-made errorsDyeingWater transport
13:52
Volumetric flow rateWater vaporDyeing
14:17
SeeschiffTypesettingVolumetric flow rateHovercraft
14:35
DyeingVolumetric flow rateModel buildingFood storageComputer animationEngineering drawing
14:49
Volumetric flow rateWater vaporComputer animation
15:02
Finger protocolGentlemanSeeschiffWind waveNegationModel buildingWater vaporComputer animationProgram flowchart
15:36
Roll formingModel buildingComputer animation
Transcript: English(auto-generated)
00:01
Rivers are dynamic systems undergoing constant change. Varying flow velocities of the water result in sand and gravel being carried away or deposited. Low water run-offs in particular can have negative consequences for shipping. Sandbanks can build up for example and move downstream.
00:23
The danger then is that ships come into contact with the river bed or even run aground. Hydraulic engineering can prevent this and improve the river system. But what are the right methods to employ? The shape and length of groins can be altered for example.
00:40
But before the responsible water and shipping authorities decide what to do, they consult the BAW, the Federal Waterways Engineering and Research Institute. The BAW is the central technical and scientific agency of the German Federal Waterways and Shipping Administration.
01:02
The BAW uses highly developed modelling and measuring techniques for both wide-ranging commission projects and scientific research. Physical models can reveal facts which are not visible in nature. They use clear water so that changes in the river bed can be observed.
01:27
Specialised analysing techniques make the processes involved visible. The models are based on studies of actual conditions in nature. For examining natural phenomena, the model analogies must be as close to nature as possible.
01:43
The findings of model studies are used in many cases, often for many years. They are linked with numerical methods, with computer simulations in other words. Numerical models simulate and display reaches in the river that are critical for shipping.
02:04
Physical models also examine the effects that measures have on the flow of flood water for example, or on the ecology of a site. Before water is fed into this model, the reference points for the optical measuring system are uncovered.
02:21
Systematic examinations of the flow at and around groins can be conducted on a simplified half-river model with a solid bed. The 27-metre length of the model represents around 800 metres of actual river. Once everything is ready, the water can be let in.
02:40
The depth of the water is regulated by a weir. If physical model analogies are complied with, the behaviour of the flowing water is similar to that in nature. White plastic discs, known as tracers, reveal the flow patterns.
03:00
What's being examined here is the effect that groins with cut-outs have on flow patterns in the groin fields. Without cut-outs, the flow pattern is that of standard groins. These tests, conducted in cooperation with the Federal Institute of Hydrology, aim to improve conditions for flora and fauna in groin fields.
03:29
The results will then be observed and analysed in nature. The level of the tracers and their speed in the flow are recorded optically by 3D particle tracking velocimetry, PTV for short.
03:46
Three cameras with different viewing angles record the white tracers. With the help of reference points, their position, level and speed in the current can be calculated. The calculation produces this image of the flow in the groin field.
04:02
Red is the strongest current, blue the weakest. This model of the River Oder is 78 metres long, representing a 7.8 kilometre stretch of the actual river. It's a complex hydraulic model with a movable bed and using advanced test and measurement techniques that are largely automated.
04:27
But some of the preparation still has to be done by hand. No two experiments involving movable beds run quite the same, so a number of tests are made, which are then statistically evaluated.
04:41
Here, the next experiment is being prepared. The two funnel-shaped containers on the roof hold the water for the experiment. They're designed to supply water at a constant pressure, so its introduction into the model can be precisely regulated. This model is examining various groin geometries in order to improve conditions for navigation.
05:07
Instead of the sand and gravel of the river bed, very light polystyrene has been chosen. This material behaves in the model just like sand in nature.
05:29
The figure is of roughly the same scale as the model, 1 to 40. Some phenomena are visible without auxiliary means, like the eddies coming from the tips of the groins.
05:43
Counter currents occur in the groin fields, made visible here by adding dye. The measuring gantry can be manoeuvred to any point on the model. Here too, the recordings are made by three digital cameras.
06:05
Triangulation computations produce a three-dimensional picture of the river bed resulting from the test. Special attention is focused on deformations of the bed. How does the bed load move in the river? Where do dunes or sand banks occur?
06:21
And how do they shift through the river? The photogrammetric data are used to produce digital terrain models. The digital terrain model data are gathered every 10 seconds for over 11 hours. This is the equivalent in nature of a measurement every 14 hours for a period of 6 years.
06:44
The BAW also examines hydraulic structures. The Obernau Barrage Dam on the River Main near Aschaffenburg consists of a 300 metre long lock, a weir, a power station and a fish ladder. The structure dates from 1930 and is now showing its age.
07:02
To make locking safer and faster and to avoid waiting times, it's planned to construct a new lock next to the old one. The weir system is also to be renovated. Before work can begin, the planners need to know how the existing and the new structures will behave during floods
07:25
and how flood waters will affect navigation. In addition, they want to find out how an inflatable weir, 250 metres downstream from the existing weir system would perform. To test all this, a solid bed model is built on a scale of 1 to 40.
07:45
We can see the new lock chamber next to the old one and the new pillars of the weir. Water is fed into the model automatically. To test how flood water affects the lock system and what conditions will be like for shipping.
08:02
The 60 metre long model represents a 2.4 kilometre long stretch of the river mine.
08:22
The effects of structures in water can be measured by various methods. Optical methods often involve the use of tracers. The BAW has developed and built this tracer dispensing machine. The staff have named it their particle accelerator. It can not only control the number of tracers dispensed,
08:42
but also precisely regulate how many are dispensed in a given time. The tracers are recorded with a camera, so the flow behaviour at any point on the model can be analysed. The four light points in the corners of the monitor serve as reference points for the calculations.
09:03
The result is this analysis, showing the distribution of flow velocities. But back to the question of how the new system will cope with flood water. It takes some time for the water to fill up to the 100 year flood level.
09:21
Even the lock control station itself is now under water. The computer charts water levels at a control point and at the weir and compares them with the acceptable 100 year flood level. The water levels are ascertained with the help of water gauges.
09:43
The measuring vessels are connected with the model according to the principle of communicating pipes. The measuring equipment uses ultrasound to measure the height of the water in the measuring vessel continuously. The data are archived immediately for further analysis and quality assurance purposes.
10:04
Like the ultrasonic water level measurer, a lot of the equipment used is not commercially available and is developed and built in the BAW's own electronics workshop. The various components of the models are also designed and constructed at the BAW.
10:22
On the basis of the plans, moulds are built into which the concrete is poured and the reinforcing inserted. The model for the Obernau retaining dam is also made of this sort of concrete elements. Once the preliminary studies are complete and all questions have been answered,
10:40
work on building the new system can go ahead. The plan for Obernau is to build an inflatable weir instead of a conventional one. It's still a little known sort of weir construction technique. The BAW has constructed a demonstration model. Recently the BAW has amassed quite some knowledge and experience of inflatable weirs.
11:03
Three are already in operation in German waterways. Electrically driven valves open and close to fill and empty the weir. The principle of communicating pipes is used for this.
11:20
Glamping rails hold the water filled weir tube in place on the river bed and at both dam pillars. The water in the tube and the regulating chamber is emptied to release the dammed up water. To dam the river, the chamber and tube are filled with water again.
11:46
The model of the new water saving lock in Minden on a scale of 1 to 25. These locks are designed to reduce water consumption in canal systems. Before a ship heading downstream can enter the lock chamber, the water level has to equal that upstream.
12:02
The old and new locks at Minden link the Mittelland canal and the river Weser. Most of the water for filling the lock comes from the water saving basins to the side, the rest from the upper canal level. Black dye is added to show the course of the water.
12:25
Filling and emptying the lock are tested and optimised in the physical model and of late via numerical detail models. The aim is to reduce the time required for filling and emptying the lock chamber by improving the number of culverts.
12:43
The culverts link the water saving basins with the pressure chamber, which is situated below the lock chamber. The water is forced from the pressure chamber via circular filling openings into the lock chamber. The dye makes the water flow visible.
13:02
What's aimed at is even distribution during filling. The new lock at Minden is equipped with three water saving basins to one side of the lock chamber. Basin 3 is built on top of Basin 1 with number 2 next to them.
13:20
The three basins save around 60% of the water needed to fill the lock chamber. To ascertain the most efficient number of culverts from the water saving basin without rebuilding, the basins were equipped with both one and two culverts. Various situations can be tested safely with the model, such as the intensity of water hammers in the case of an operating error,
13:46
or an emergency stop when the valves in the culverts are closed quickly. Dye is also used to reveal the flow behaviour of the water leaving the lock chamber.
14:08
This creates strong turbulence in the water of the lower canal. This test examines various shapes of filling openings at a scale of 1 to 10.
14:23
The formation of surface flushes and the intensity of the outflow are tested to avoid problems later for ships and pleasure craft in the lock chamber. The flow behaviour is again made visible using dye.
14:40
All the processes in the model are controlled by a computer installed in a measuring booth. It also stores all the data and immediately displays the measurement results following a test. Valves control the flow of water to and from the lock chamber and water saving basins.
15:02
Schedules for the valves are worked out which take into account the maximum permissible forces exerted on ships and avoid negative effects such as abrupt surge waves. Emptying the lock chamber and filling the water saving basins to the left are shown here with 8-fold time lapse.
15:21
The filling and emptying system of the new lock at Minden shown in the model is based on the system used at the Iltsen 2 lock. The Iltsen 2 design was also tested and optimised in a physical model form
15:42
at the Federal Waterways Engineering and Research Institute in Karlsruhe.
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