2.2 Optimization of wind booster
As mentioned in Section 2.1, number, shape, and leading angle of the guide vanes are regarded as design variables in optimization. It can be seen that the shape of the guide vane is a qualitative variable, which cannot be numerically determined for optimal results. Hence, the potential shapes are proposed in structures of curved side triangle,straight side triangle, and straight line, as shown in Fig.4(a), (b), and (c), respectively, as optimization cases.