In a conventional design and manufacturing process, turbine blades are modeled based on reverse engineering or on parametric modeling with Computer Fluids Dynamics (CFD) optimization. Then, only raises the question of the manufacturing of the blades. As the design does not take into account machining constraints and especially tool path computation issues in flank milling, the actual performance of the machined blade could not be optimal. In this paper, a new approach is used for the design and manufacture of turbine blades in order to ensure that the simulated machined surface produces the expected hydraulic properties. This consists in the modeling of a continuous tool path based on numerical simulation rather than the blade surface itself. Consequently, this paper aims at defining the steps of the proposed design approach including geometrical modeling, mesh generation, CFD simulation and genetic optimization. The method is applied on an isolated blade profile in a uniform water flow and results are compared to the conventional design process.