Sekavcnik M presented a one-stage outward radial turbineworking with ideal gas, and estimated the aerodynamic perfor-mance by using one dimensional analysis and numerical simulation in 1998. In recent years, Casati, Persico and Pini studied theflow characteristics of centrifugal turbines for the ORC system. Aone-dimensional calculation code for the preliminary design ofmulti-stages centrifugal turbines was developed, and the aerodynamicperformance assessments of centrifugal turbines werevalidated by means of numerical simulation. Welch and Boyle designed a radial outflow turbine for geothermal power plants andits isentropic efficiency was over 80%. Al Jubori et al. conductedthe 1D design and 3D analysis for a small-scale axial and radial-outflowturbine, respectively, with five different working fluids(R141b, R245fa, R365mfc, Isobutane, n-Pentane). Martins et al. presented a novel optimal design method which was applicable notonly to radial inflow, axial and radial outflow turbines, but to superheatedand supercritical cycle configurations.