title: The acoustic attenuation and hydraulic roughness in a large section sewer pipe with periodical obstacles.
abstract: The acoustic attenuation, relative sound pressure levels and the equivalent Nikuradse wall roughness under variable flow conditions in a 600 mm concrete sewer pipe are experimentally investigated. The values of the acoustic attenuation are obtained in the case of airborne sound propagation in the dry pipe. A range of values of the equivalent wall roughness is artificially generated by deploying a periodical array of engineering bricks. A novel method of rapid evaluation of the acoustic attenuation is proposed. The method relies upon sound reflections from the adjacent manholes. The results demonstrate that the acoustic attenuation depends strongly on the value of the equivalent wall roughness. This work can pave the way to the efficient methodology for the in-situ, physical evaluation of the equivalent hydraulic roughness of new and existing sewer networks.
authors.affiliation: Pennine Water Group, School of Engineering, Design and Technology, University of Bradford, Bradford, West Yorkshire, BD7 1DP, UK. k.horoshenkov@bradford.ac.uk
authors.forename: K V
authors.initials: KV
authors.lastname: Horoshenkov
authors.forename: Y A
authors.initials: YA
authors.lastname: Yin
authors.forename: A
authors.initials: A
authors.lastname: Schellart
authors.forename: R M
authors.initials: RM
authors.lastname: Ashley
authors.forename: J R
authors.initials: JR
authors.lastname: Blanksby
mesh_terms: D000162:Acoustics; D004738:Engineering; D004784:Environmental Monitoring / Q000379:methods; D012722:Sewage; D014865:Waste Disposal, Fluid / Q000295:instrumentation* / Q000379:methods*; D014872:Water Movements
chemical_list: D012722:Sewage