Modelling of fluid machines as sources of sound in duck and pipe systemsLavrentjev, Jüri; Abom, Mats; Boden, HansINTER-NOICE 96, Southampton, 19961996 https://www.researchgate.net/publication/285343911_Modelling_of_fluid_machines_as_sources_of_sound_in_duct_and_pipe_systems