Aeroacoustic Noise from Building Façades – Observed Problems and Approaches to Mitigation

Abstract

As wind passes over and around a building there are aerodynamic interactions between the airflow and building features.  This includes local accelerations of flows, the generation of turbulence, and the potential formation of vortices in the wake of building features.  Under certain conditions this interaction can result in the generation of audible tones.  If the amplitude of the generated tone is sufficiently high, and its characteristics are distinctly different from the existing background noise level, disturbance to the building and its surrounding environment is possible.

Several phenomena are attributed to the generation of aerodynamic noise.  Many of these relate to physical conditions that are often exploited in musical acoustics to produce an efficient generation of sound by coupling airflow or vibration to a resonant object.  Whereas in musical acoustics the instruments are tuned to produce specific pitch and timbre, conditions of aerodynamic noise generated by buildings are generally unexpected, unwanted, and unmusical.  When these problems occur, they often become publicized due to noise complaints, and can lead to loss of revenues, costly remediation, and potential damage to the reputation of the building owner and designers.  As such, there is a desire to identify risk during the design of the building and take appropriate steps to mitigation of risk where noise generation is possible.

In this presentation we discuss the common sources of aeroacoustic resonances that occur on building façade features, some of the techniques used to establish risk of noise problems, and approaches to managing risk and mitigation measures.  Examples are presented from projects around the globe that include some of the world’s tallest buildings.  Numerical and experimental methods of assessment are reviewed and a general framework for assessment is presented.