Automated operation of chains of barrages – development of controller algorithms with the use of model-based design

River engineeringFlow management and contro

BAW-Brief Nr. 1 - Juni 2009

600-W, Wasserbau, Reglerentwurf und automatische Codegenerierung599-W, Wasserbau, Erste Erfahrungen mit der Umsetzung der automatisierten Abfluss- und Stauzielregelung an der Mosel598-W, Wasserbau, Modellgestützte Festlegung von Regelungsparameter

Ionization wave propagation on a micro cavity plasma array

Microcavity plasma arrays of inverse pyramidal cavities have been fabricated in p-Si wafers. Each cavity acts as a microscopic dielectric barrier discharge. Operated at atmospheric pressure in argon and excited with high voltage at about 10 kHz, each cavity develops a localized microplasma. Experiments have shown a strong interaction of individual cavities, leading to the propagation of wave-like optical emission structures along the surface of the array. This phenomenon is numerically investigated using computer simulation. The observed ionization wave propagates with a speed of about 5 km/s, which agrees well the experimental findings. It is found that the wave propagation is due to sequential contributions of a drift of electrons followed by drift of ions between cavities seeded by photoemission of electrons by the plasma in adjacent cavities

Comparing wavelengths simulated by the coastal wave model CWAM and TerraSAR-X satellite data

The accuracy of the high resolution coastal wave forecast model CWAM is validated on the basis of sea state information from satellite images of TerraSAR-X (TS-X). Employing 2-dimensional Fast Fourier Transformation, image spectra are derived from TS-X and locally varying patterns of the peak wavelengths are provided. Subsequently, wavelength comparisons are performed between a typical set of TS-X scenes acquired in December 2013 over the German Bight and the model hindcasts. This results mostly in reasonable agreement. Potential wave modelling errors are discussed as well