Chapter 41
Study of Acoustic Emission Response
to Vortex Shedding of a Bluff Body
Fatematuz Zohora, David Holmes, Pietro Borghesani, Michael Cholette,
and YuanTong Gu
Abstract Acoustic emissions (AE) have been used to detect fluid flow disturbances
such as leaks in pipes and turbulence. In such scenarios, fluid dynamics characteristics
can be observed at a pipe wall using an AE sensor as a result of complex mechanical
interactions. The purpose of this study is to understand the relationship between fluid
dynamic force (lift force) at a circular bluff body inside a pipe, and the AE response
to this force. Both experimental and numerical studies were conducted to understand
this relationship. This investigation reveals that the generated lift force was weak. As
a result, the pipe wall response in terms of deformation, velocity, and acceleration
was small, and the AE sensor failed to detect the signals. The findings indicate that
numerical study can be used as a guide to design AE condition monitoring strategies
and to understand what type of disturbance profiles can and cannot be detected.
41.1 Introduction
Acoustic emission (AE) is a popular non-destructive testing technique used in condition monitoring. An AE generating event causes surface motion of a structure in the
form of elastic waves. An AE sensor plays a critical role as it records this surface
motion and converts it into a voltage–time waveform. Importantly, AE has been
used to detect fluid flow disturbances like leaks in pipes or high turbulent flow [1].
AE technique thereby can be used for investigating the relationship between fluid
dynamics, and the corresponding mechanical phenomenon at the pipe wall.
When flow passes over a body, the body creates an obstacle to the flow path and
generates a wake region downstream. In this scenario, the body is known as a bluff
F. Zohora · D. Holmes (B) · M. Cholette · Y. Gu
School of Mechanical, Medical and Process Engineering, Queensland University of Technology,
Brisbane, QLD 4000, Australia
e-mail: d.holmes@qut.edu.au
P. Borghesani
School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney,
NSW 2052, Australia
e-mail: p.borghesani@unsw.edu.au
© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2021
G. Shen et al. (eds.), Advances in Acoustic Emission Technology, Springer Proceedings
in Physics 259, https://doi.org/10.1007/978-981-15-9837-1_41
465
Study of Acoustic Emission Response
to Vortex Shedding of a Bluff Body
Fatematuz Zohora, David Holmes, Pietro Borghesani, Michael Cholette,
and YuanTong Gu
Abstract Acoustic emissions (AE) have been used to detect fluid flow disturbances
such as leaks in pipes and turbulence. In such scenarios, fluid dynamics characteristics
can be observed at a pipe wall using an AE sensor as a result of complex mechanical
interactions. The purpose of this study is to understand the relationship between fluid
dynamic force (lift force) at a circular bluff body inside a pipe, and the AE response
to this force. Both experimental and numerical studies were conducted to understand
this relationship. This investigation reveals that the generated lift force was weak. As
a result, the pipe wall response in terms of deformation, velocity, and acceleration
was small, and the AE sensor failed to detect the signals. The findings indicate that
numerical study can be used as a guide to design AE condition monitoring strategies
and to understand what type of disturbance profiles can and cannot be detected.
41.1 Introduction
Acoustic emission (AE) is a popular non-destructive testing technique used in condition monitoring. An AE generating event causes surface motion of a structure in the
form of elastic waves. An AE sensor plays a critical role as it records this surface
motion and converts it into a voltage–time waveform. Importantly, AE has been
used to detect fluid flow disturbances like leaks in pipes or high turbulent flow [1].
AE technique thereby can be used for investigating the relationship between fluid
dynamics, and the corresponding mechanical phenomenon at the pipe wall.
When flow passes over a body, the body creates an obstacle to the flow path and
generates a wake region downstream. In this scenario, the body is known as a bluff
F. Zohora · D. Holmes (B) · M. Cholette · Y. Gu
School of Mechanical, Medical and Process Engineering, Queensland University of Technology,
Brisbane, QLD 4000, Australia
e-mail: d.holmes@qut.edu.au
P. Borghesani
School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney,
NSW 2052, Australia
e-mail: p.borghesani@unsw.edu.au
© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2021
G. Shen et al. (eds.), Advances in Acoustic Emission Technology, Springer Proceedings
in Physics 259, https://doi.org/10.1007/978-981-15-9837-1_41
465