Aeroacoustic Analysis of a Wind Turbine with Sinusoidal Leading-Edge Blade

Abstract

Wind turbines are a major source of renewable power generation in the U.S with a share of 4.7% in total electricity produced and is a clean energy source. While wind energy has its advantages, it also has room for improvement and few drawbacks. One of the drawbacks is the noise associated with the operation of the wind turbine and its impact on nearby communities. The noise generated from wind turbines is known to cause annoyance and sleep disturbance to the people living nearby and few countries have acted to regulate the installation of wind turbines near communities. The primary aim of this research is to design a wind turbine blade with tubercles and evaluate it's aerodynamic and noise performance. A preliminary step in achieving this goal is to perform 3D steady flow analysis and noise analysis on a base model, namely the NREL Phase VI blade using commercial CFD software, STAR CCM+. Three-dimensional steady RANS equations with SST k-ω turbulence model with all y+ wall treatment is used to perform numerical analysis of the blade at five different wind speeds from 7m/s to 25m/s, by keeping the wind turbine angular speed constant at 72RPM. To reduce computational cost and time, only one blade is analyzed instead of two, and a periodic boundary condition is used with 1800 symmetry. The pressure data from the CFD results are used as an input to Curle Broadband Noise source model to estimate the sound Pressure level (SPL). This process aids in validating the prediction that the bionic wind turbine blade can be more efficient and generate less noise than a conventional wind turbine at the same wind speeds.