**Abstract**

Wind turbine blades are known for their complex geometry and difficult-topredict characteristics. So, this chapter aims to look in depth at theory, design, modeling, and simulation of a 1.2 MW wind turbine blade (35 m). Computational fluid dynamics (CFD) will be used to simulate the blade. The design tip speed ratio (TSR), the center point of the design, is optimally chosen as 7. The various parameters like torque vs TSR, Cp, and Ct vs TSR will be found for varying pitch angles. Simulations will be performed on the blade, and the results will be compared with those obtained from blade element & momentum (BEM) theory. Along with this, QBlade and XFoils results are compared with a much more accurate CFD simulation. To conclude, the accuracy of various methods will be compared and evaluated.

**Keywords:** wind turbine, HAWT, CFD, fluent, BEM, NREL, renewable, mechanical
