Paper describes CFD calculations of water flow about floating rotor for new large-scale vertical axis wind turbine supported by pontoon with columns (WEMU type). The research goals are to verify flow mode, to calculate a hydrodynamic power loss, to find out an influence of waves. Water ring arises about the pontoon during rotation. Power loss is proportional to second power of rotational velocity. The ring can drift to outside because of water acceleration and aside due to waves.
Offshore wind power plants seem to be the most promising and quickly growing area in wind power engineering. They have obvious advantages over inland power plants. First, they have softer ecological demands, higher blade speed, and therefore, increased efficiency. However, the substantial differences between modern offshore and onshore turbines are located in their support structures only. So, wellknown drawbacks of propellers could not be excluded. The limited unit power capacity, infrasound emission, and the harmful effect on birds and animals are noted. Now wind energy cost is higher than that from conventional power plants. In spite of some new projects of offshore horizontal-axis wind turbines having increased power capacity, evidently their capacity has come close to a technological limit. The studies revealed (e.g., Klinger F. et al, 2002) that an efficient 10MW turbine could not be developed within the framework of Dutch design. Our aims are to increase substantially unit capacity of wind power plants, to work safely under extra wind loads, to enhance wind speed range, to reduce wind energy cost, to eliminate infra sounds and fatal injury of birds due to turbine rotation. The aims can be reached with the recently suggested concept of wind turbines named the Wind Energy Marine Unit (WEMU) (Cheboxarov et al, 2002; Cheboxarov and Cheboxarov, 2002).