**4. Results and discussion**

In this section we present results for the turbulent boundary layer vortex shedding noise from a 2 MW horizontal axis wind turbine blade using original BPM model predictions, modified by [9] and compare them with numerical computations implemented using the correction function for airfoil thickness. **Figure 5** illustrates the noise prediction from wind turbine blades using first order empirical methods which are based on the turbine geometric and operating parameters viz. rotor diameter, nominal power rating of machine and blade tip speed. Although such methods can predict sound power levels, they do not take account of the physical phenomenon responsible for the noise radiation from rotating blades at broadband frequencies and hence not reliable. Also, it can be said noise models proposed by [21–23] are simple algebraic functions that depend on nominal power

**Figure 5.** *Illustration of sound power level based on empirical relations proposed by [19–21].*

