[1] Graz Univ Technol, Inst Thermal Engn, Inffeldgasse 25b, A-8010 Graz, Austria
[2] Hargassner GesmbH, Anton Hargassner Str 1, A-4952 Weng Im Innkreis, Austria
[3] Carlos III Univ Madrid, Thermal & Fluids Engn Dept, Avda Univ 30, Leganes 28911, Madrid, Spain