As an effort to reduce carbon emissions, Germany plans to significantly increase the use of wind and PV electricity. Since wind and PV plants cannot be dispatched deliberately like conventional power plants, increased flexibility on the demand side is needed to efficiently utilize the intermittent renewable generation. This Dissertation evaluates the suitability of building energy systems in non-residential buildings to provide load flexibility by adapting their load and generation trajectories according to the market need. It is explored how the "grid support" of buildings can be quantified, how grid-supportive present-day building energy systems are operated, and which approaches are most suitable to improve the grid support of buildings. To this end, four different flexibility and storage options (batteries, fuel switch, water tanks, and the thermal building mass) are compared in terms of improvement in grid support and impact on energy efficiency.
Electro-optical and laser systems are presently deployed in naval operations around the world. The performance of these systems is negatively affected by optical turbulence in the atmosphere, quantified by the parameter Cn2. The strength of the integrated optical turbulence Cn2 was investigated for several coastal locations in different climatic conditions: False Bay (South Africa), the Baltic Sea (Bay of Eckernförde, Germany), the Mediterranean Sea (Crete, Greece), the Gulf of Mexico (Dauphin Island, Alabama, US), and the Arabian Gulf. The over-water, near-surface turbulence was characterized along paths that typically spanned 1.5 - 8.7 km using large aperture scintillometers. The dependency of Cn2 on the air-sea surface temperature difference and wind speed is discussed, and the results for the five geographic regions are compared and discussed in terms of environmental conditions and climate.
A full-span droop-nose leading edge is proposed in the Clean Sky GRA project as a next-generation low-noise high-lift device. This device can prevent flow separation on the upper wing surface at large angles of attack and therefore provides high lift. The device is also considered to be promising for reducing noise because no gaps are found between the leading edge and the wing. These features have been admitted in CFD and CAA analyses. In this study, they were experimentally confirmed in wind tunnel tests using a 1:6-scaled half wing model. The model generally showed similar aerodynamic performance to that estimated in CFD analysis. An exception was that the droop-nose configuration provided very large lift and a large stall angle when no transition tripping devices were equipped. In an acoustic beamforming experiment, no extra noise sources were found at the droop nose leading edge. This device did not increase the noise level. By analyzing microphone signals in the far field, an indication of noise radiated from the wing model could be detected at higher frequencies, although entire noise spectra could not be determined because the microphone signals were largely contaminated by the noise from the wind tunnel itself.