The performance of two model ship propellers in open water condition is predicted with the FINFLO RANSE-solver. Chien´s low Reynolds number k-e turbulence model is applied and the method of artificial compressibility is used. For propeller P21 the predicted torque coefficient for advance number 0.324 and 0.519 differ by less than 1,6% from experimentally obtained values. The difference for the thrust coefficient and the open water efficiency is a little higher, but still less than 7% for both advance numbers. For propeller P89 the open water efficiency differs by less than 1,0% for advance number 0.331 and 0.514. The thrust and torque coefficients are predicted within 3,3% for both advance numbers. The averaged velocities in the flow around the propellers correspond very well to measurements. The largest difference is for the tangential velocities behind the propeller. The best agreement is achieved for the radial velocities in front of the propeller and the axial velocities behind it.