Noise reduction of a tractor exhaust tailpipe with bionic convex textures

摘要

Exhaust system noise is a major noise source of diesel tractor engines. In this article, this problem is improved by using bionics to alter the noise transmission route. By imitating the unique microstructures of owls, goshawks and sharks, the noise reduction effect was studied by designing bionic surface textures for the inner walls of exhaust tailpipes through bionic modification. Different shapes of textures (rectangle, sine, diamond, triangle, inverted triangle, and a combination of all 5 different shapes) with heights of 1.5 mm were designed for application on the inner walls of the exhaust tailpipes. Under the premise of not changing the structure and arrangement of the entire exhaust tailpipe system, bionic non-smoothing and basic acoustic theories were used in 3D modeling, mesh discretization and acoustic simulation for each convex texture. The noise reduction effects on different tractor bionic exhaust tailpipes were studied while utilizing identical convex texture heights, and the convex texture with the best noise reduction effect was identified. (C) 2019 Institute of Noise Control Engineering.