GWK+
New Large Wave Flow Channel at the Coastal Research Center
From GWK to GWK+
In recent years, the demands on coastal protection as well as advances in marine technology and especially in the extraction of renewable energy on and from the sea have steadily increased, and this trend is expected to intensify in the future. To further advance research and development in these areas, the BMWK funded the marTech (maritime technologies) project with 35 million euros. As part of this project, a unique experimental facility was created from the GWK, which allows the best possible reproduction of natural environmental conditions at sea on a large scale in the laboratory. All major effects of waves and (tidal) currents are simulated and the natural seabed conditions are represented. The GWK+ is a joint institution of Leibniz Universität Hannover and Technische Universität Braunschweig at the Forschungszentrum Küste.
Research focus
Research Goals
- Hydrodynamic loading of the support structures of WTGs.
- Scouring and scour protection measures
- Soil-Structure Interactions
- Stability and anchoring systems of floating structures
- Performance optimization of wave and tidal current systems
Special features
- With a new more powerful wave machine, larger waves and loads can be generated, which will allow even more realistic testing and further development of structures under extreme conditions
- A flow generation facility can be used to generate tidal currents, for example, to study their impact on sediment stability and structures, and to consider and analyze nonlinear wave-current interactions
- A deep section in the center of the channel allows sediment to be placed at ground level. Structures can be realistically bedded, deep foundations can be investigated with their dagrading effects, and nonlinear structure-soil interactions can be captured
New wave machine
Parameters of the new wave machine:
- 7m high piston type shaft flap with dry backside
- Compensation of hydrostatic pressure by air pressure
- Drive via pinions and racks by 8 electric servo motors
- Maximum stroke: approx. 7.5 m
- Maximum wave heights that can be generated: approx. 3 m
- Active absorption of reflected waves
New flow system
The flow facility consists of 2 inlet and outlet structures, respectively, 152 m apart. The flow is directed into the channel through an opening at the bottom. The flow profile can be optimized with individually controllable louvers in the openings. The two inlet/outlet structures are connected by 2 pipelines, each with an internal diameter of 2 m, and a centrally located underground pump house. The pumps allow a maximum flow of 20 m³/s, which corresponds to an average flow velocity of 0.8 m/s at 5 m water depth. Any hydrographs can be controlled. In addition to the flow, the channel filling and emptying can also be controlled simultaneously with the flow in order to realistically simulate tidal cycles.
New deep part
The new deep section is located in the middle between the inlet and outlet structures. Over the entire width of the channel and over a length of 28 m, the bottom is lowered by 2 m. A short area of 8 m is lowered a further 4 m, so that maximum bedding depths of approx. 6 m are possible there. If a level solid base is required, the two areas can be covered separately with concrete planks.
