Genetic algorithms evolve in a monotonic way. The rate of convergence is slow. Note that for the same amount of effort, a Simplex method will give a better solution which however is not the best possible. The cost function can be a weighted combination of the different characteristics such as the energy production, the mass of the blade, the level of emitted noise, etc. The weights in such an expression indicate the perspective the design should have.
Suitable constraints are essential for resulting to acceptable designs.
The requirement of a blade to meet strength requirements leads to a constraint expressed for example by limiting the maximum of the flapping moment at root. Other constraints can be set on the geometry of the blade so as to get meaningful shapes. For example the chord distribution must be a decreasing function of the radius. In order to complete the formulation the designer must choose the design variables which will be determined by the solution of the optimization problem. Since the primary target of rotor optimization is high energy efficiency, the choice of the airfoils is essential.