This paper describes the generation of blade–tower interaction (BTI) noise from upwind turbines and pylon-mounted fans using a combination of experimental and numerical means. An experimental rotor-rig was used in an anechoic chamber to obtain BTI acoustic data under controlled conditions. A computational model, based on the solution of the unsteady Reynolds Averaged Navier Stokes (URANS) equations and Curle’s acoustic analogy, was used to describe the generation of fan and simplistic model of wind turbine BTI noise by the rotor-rig. For both the fan and model wind turbine case, the tower was found to be a more significant source of BTI noise than rotor blades. The acoustic waveforms for both turbine and fan are similar; however, in the case of the turbine, the blade contribution reinforces that from the tower, while in the case of a fan, there is some cancellation between the tower source and the blade source. This behavior can be explained by the unsteady aerodynamics occurring during BTI.
Branko Zajamsek, Kristy L. Hansen, College of Science and Engineering, Flinders University, Adelaide, Australia
Yendrew Yauwenas, Con J.Doolan, Victoria Timchenko, John Reizes, School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, Australia
Colin H. Hansen, School of Mechanical Engineering, University of Adelaide, Adelaide, Australia
Journal of Sound and Vibration
Volume 443, 17 March 2019, Pages 362-375
doi: 10.1016/j.jsv.2018.11.048 
Download original document: “Experimental and numerical investigation of blade–tower interaction noise ”