Publications (UMIL)

Josep Rodríguez-Sendra, Monitorización Ultrasónica de Tejidos Odontológicos, Universitat Politècnica València, September 2021.

Sergio Jiménez-Gambín, Transcranial Ultrasound Holograms for the Blood-Brain Barrier Opening, Universitat Politècnica València, June 2021.

Noé Jiménez, Nonlinear Acoustic Waves in Complex Media, Universitat Politècnica València, June 2015.

Acoustic Waves in Periodic Structures, Metamaterials, and Porous Media
N Jiménez, O Umnova, J Groby

Springer International Publishing, Cham, Switzerland, (2021)
Abstract – This book delivers a comprehensive and up-to-date treatment of practical applications of metamaterials, structured media, and conventional porous materials. With increasing levels of urbanization, a growing demand for motorized transport, and inefficient urban planning, environmental noise exposure is rapidly becoming a pressing societal and health concern. Phononic and sonic crystals, acoustic metamaterials, and metasurfaces can revolutionize noise and vibration control and, in many cases, replace traditional porous materials for these applications. In this collection of contributed chapters, a group of international researchers reviews the essentials of acoustic wave propagation in metamaterials and porous absorbers with viscothermal losses, as well as the most recent advances in the design of acoustic metamaterial absorbers. The book features a detailed theoretical introduction describing commonly used modelling techniques such as plane wave expansion, multiple scattering theory, and the transfer matrix method. The following chapters give a detailed consideration of acoustic wave propagation in viscothermal fluids and porous media, and the extension of this theory to non-local models for fluid saturated metamaterials, along with a description of the relevant numerical methods. Finally, the book reviews a range of practical industrial applications, making it especially attractive as a white book targeted at the building, automotive, and aeronautic industries.pdf / url / doi / abstract / bibTex

ISBN: 978-3-030-84299-4

The Transfer Matrix Method in Acoustics
N Jiménez, J Groby, V Romero-García

Chapter in: Acoustic Waves in Periodic Structures, Metamaterials, and Porous Media: From Fundamentals to Industrial Applications, pp. 103 – 164
Editors: N Jiménez, O Umnova, J Groby
Springer, Cham, Switzerland, (2021)
Abstract – The transfer matrix method is a simple but powerful analytical tool used to model acoustic wave propagation in a wide range of one-dimensional problems. In this chapter, we present the method and summarize the most common building blocks encountered in one-dimensional acoustic systems. These include layers of fluids and porous media, ducts and waveguides of different geometries where thermoviscous losses can be accounted for, locally reacting elements such as Helmholtz or quarter-wavelength resonators, viscoelastic plates and membranes, micro-perforated panels or vibrating walls. Several examples are provided, including a multi-layered porous structure for room acoustics, the transmission problem of a double-leaf wall for building acoustics, and the analysis of the dispersion relations of acoustic waves in periodic media and metamaterials using locally resonant elements. Various one-dimensional wave-motion phenomena can be studied using the generalized framework provided by the transfer matrix method such as reflection, transmission, absorption, attenuation and dispersion, as illustrated in the examples.pdf / url / doi / abstract / bibTex

ISBN: 978-3-030-84299-4

Acoustic Metamaterial Absorbers
J Groby, N Jiménez, V Romero-García

Chapter in: Acoustic Waves in Periodic Structures, Metamaterials, and Porous Media: From Fundamentals to Industrial Applications, pp. 167 – 204
Editors: N Jiménez, O Umnova, J Groby
Springer, Cham, Switzerland, (2021)
Abstract – Porous and fibrous materials provide effective and broadband acoustic absorption at mid/high audible frequencies. However, these traditional treatments result in thick and heavy layers when designed for low frequency audible sound. To overcome these limitations, in the recent years metamaterials have been proposed as an alternative to design sub-wavelength and efficient absorbing structures. In the current chapter, we review the recent advances in metamaterial absorbers and their underlying physics based on the analysis of the scattering matrix. Particularly, we exploit the physical interpretation of the eigenvalues and eigenvectors of the scattering matrix in the complex frequency plane to design efficient absorbers. We start by the discussion of the reflection problem, where these eigenvalues and eigenvectors collapse to the reflection coefficient. We state the conditions to design efficient and perfect metamaterial absorbers. Then, we increase the complexity of the scattering considering the transmission problem, where additional conditions are needed for designing perfect absorbers. Through this chapter we discuss different acoustic metamaterials based on metaporous absorbers, arrays of Helmholtz resonators and air cavities, as well as membrane and elastic-plate resonators.pdf / url / doi / abstract / bibTex

ISBN: 978-3-030-84299-4

Noé Jiménez. Materials for Acoustic Wave Generation and Modulation. Chapter in: Acoustic Technologies in Biology and Medicine, pp. 317-331. Editors: A Ozcelik, R Becker, TJ Huang. Wiley-VCH Verlag GmbH, Weinheim, Germany, (2023)

ISBN: 978-3527350629