Session: 01-02-02: Acoustic Metamaterials

Paper Number: 145225

145225 - Optimized Design of Acoustic Blackhole for Broadband Noise Attenuation in Ducts 

Broadband noise attenuation remains a challenging problem in ducts. The development of
acoustic metamaterials in recent times has made it possible to control and manipulate sound
waves in novel ways. Acoustic black holes (ABH) are passive-type absorbers. The two major
parameters affecting the sound absorption characteristics of ABH are known as power-law
decay of duct radius and tailored wall admittance. In theory, the tailored geometry induces
power-law decay of wave propagation velocity, and the incident wave gets trapped inside the
geometry without any reflections. The current study aims to develop an optimized ABH
design targeting broadband frequency. The transfer matrix method (TMM) approach is used
to characterize the reflection coefficient and validated using a numerical approach considering
thermoviscous effect along the thin walls. The developed basic design is further optimized for
the influencing parameters and validated using numerical analysis. The result shows a
broadband noise attenuation for the optimized design of the black hole.

Presenting Author: Biren Kumar Pradhan Indian Institute of Technology Kharagpur

Presenting Author Biography: Biren Kumar Pradhan is a research scholar from the Department of Mechanical Engineering at IIT Kharagpur, India. He has completed his B.Tech from VSSUT, Burla (2015) and M.Tech from NIT Rourkela (2018). Currently, he is pursuing PhD under the supervision of Prof. Amiya Ranjan Mohanty and is affiliated with Acoustics and Condition Monitoring Lab. He has worked in many challenging areas of noise control such as Aeroacoustics, Acoustic metamaterials, and Active noise cancellation. His research area includes Noise control using active and passive techniques, Computational Fluid Dynamics, and Real-time Digital signal processing.

Authors:

Biren Kumar Pradhan Indian Institute of Technology Kharagpur
Amiya Ranjan Mohanty Indian Institute of Technology