Aircraft noise pollution has a solution in owl wings design

Scientists look at owl wings to find ways to cut down aircraft and turbine engine noise pollution

How do you reduce noise pollution that fills the air due to the turbine engines and aircraft? This has been a topic of research for long. Of late, scientists seem to be closing in on a viable solution to this issue.

 There have been studies to find how to reduce the trailing-edge noise that emanates from turbines and airplanes, research has found that nature itself has provided a solution that could go a long way in addressing the issue. The need for such a study had come due to the ever increasing noise pollution from such engines in urban environments.

A research paper published in the journal ‘In Physics of Fluids’ has scientists from the Xi’an Jiaotong University trying to capitalise on the characteristics of owl wings to be adopted in airfoil design. This, they believe, would significantly cut down on trailing-edge noise.

Trailing-edge noise calls for reduction

In case you aren’t aware of what trailing-edge noise, it is the sound that is thrown out when airflow passes along the back of an airfoil. This air flow creates a turbulent layer of air along the upper and lower surfaces of the airfoil. And when such an air layer flows back through the trailing edge, it gets scattered producing noise.

The results came about after it was realised that night owls produce about 18 decibels less noise than other birds at similar flight speeds due to their unique wing configuration. Also, when these nocturnal owls catch hold of their prey the constant change of the shape of the wings was studied. It was then found that the wing edge configuration during owl flight could throw light on how the airfoil design can be altered.

Research looks at design of airfoils similar to owl wings

Rotating turbo machines have undergone significant alterations in design over the past few years. However, this has not contributed much in reduction of noise. Researchers feel that noise reduction capabilities of the saw tooth structures that are in use are so less, calling for the need for further development so as to see how bionic noise reduction can be achieved.

This led them to learn more on noise calculation, following which the simplified airfoils with characteristics that are akin to owl wings were researched on. By altering the trailing edge and optimising the shape of the edge were found to help in reduction in the noise.  Researchers are now working on how to improve this by focusing more on the airfoil designs.

It is believed that these study results would go a long way in effectively cutting down on noise pollution.