AERODYNAMIC NOISE

Reduction of Aerodynamic Noise in Wind Turbines

[Name of Supervisor]

Reduction of Aerodynamic Noise in Wind Turbines

Introduction

There are many factors of pollution present our environment. One major factor is noise pollution which is due to a number of reasons. Among them wind turbine is also considered as one of the important reason of producing noise pollution. It is observed that people are mostly worried about the noise while anything new is going to be established in their area either it's a road, a club or a shopping centre. Thus wind turbines also produce mush disturbance for the neighbor farms. Noise in wind turbine is generated through various aerodynamic and mechanical sources. With the advancement in the technology, many techniques have been implemented in order to reduce the noise. But still the noise e from wind turbine is a concern for the people living in the surrounding. In wind energy engineering the concerns related to wind turbine noise has now turned out to be major environmental impact area. It is easy to measure the level of noise but the public's insight of the noise impact of wind turbines is in part a subjective purpose (Arakawa, et.al. 2005).

Discussion

Aerodynamic Noise

Aerodynamic noise is generated with the flow and pressure of the air around the blades. Rotor speed generally increases the aerodynamic noise. This is generally considered as one of the biggest source of the noise generated by wind turbine. This noise is further classified into three different categories:

1) Low Frequency Noise: It depends on the sound range with the minimum frequency. This is produced when localized flow deficiencies are encountered by the rotating blades surrounding a tower, change in wind speed occurs.

2) Inflow Turbulence Noise: It is basically atmospheric turbulence dependent which results in causing the local pressure or local force fluctuations within the edges of the blade.

3) Airfoil Self Noise: It depends on the air flow generated noise with the surface of the airfoil. This noise generally dependent on a broadband characteristic, but noise can be a result of flow over holes and or blunt edges (Kim, et.al. 2012).

Noise Reduction Procedures

In order to minimize the noise it is highly recommended to design the gear teeth with by specially emphasizing on the finishing by utilizing cooling fans of low speed as well as by using the nacelle rather than ground level and by using soft mounts and vibration isolators for significant elements and designing the ...