Institute for Thermal Turbomachinery and Machine Dynamics Graz University of Technology Univ.-Prof. Dr.-Ing. Franz Heitmeir Inffeldgasse 25a / A-8010 Graz Institute for Mechanics Graz University of Technology Univ.-Prof. Dr.-Ing. habil. Katrin Ellermann Kopernikusgasse 24/IV A-8010 Graz Institute for Mechanics and Mechatronics Vienna University of Technology Ao.Univ.Prof. Dipl.-Ing. Dr.techn. Horst Ecker Getreidemarkt 9/E325,A3 A-1060 Wien