A team of students from Johns Hopkins University has designed a 3D printed add-on that significantly reduces the noise of modern electric leaf blowers. Despite electric models being quieter than gas-powered ones, the noise can still be disruptive, especially in residential areas. The students’ suppressor, developed after identifying that most noise comes from high-speed air exiting the nozzle, addresses this by targeting and canceling harsh frequencies.
The team began by disassembling an electric leaf blower to study its components and determine the primary source of the noise. They discovered that the noise was mainly due to the complex interactions of high-speed air rather than mechanical sounds. By isolating the frequencies most unpleasant to the human ear, the students designed a suppressor that mitigates these specific sounds.
Stanley Black & Decker plans to commercialize the device within two years. While technical details are sparse due to the commercial partnership, it is known that the suppressor works by redirecting a portion of the air into printed channels. These channels slow down the air before it re-enters the main airflow, reducing the overall noise level- exactly like a firearm suppressor (or “silencer”, as they say in the movies).
Although the suppressor doesn’t eliminate noise completely, it significantly reduces the most annoying high-pitched sounds, making the blower’s noise more tolerable. Initially designed as an add-on for existing blowers, it is anticipated that Stanley Black & Decker might integrate the technology directly into future models.
Source: hackaday.com