1. Institute of Fluid-Flow Machinery Polish Academy of Science, ul. Fiszera 14, 80-231 Gdańsk, Poland
2. Faculty of Power and Aeronautical Engineering, Warsaw University of Technology, ul. Nowowiejska 21/25, 00-665 Warsaw, Poland
3. Department of Electrical Engineering, Mathematica and Computer Science,University of Twente, PO BOX 217, 7500 AE Enschede, Netherlands