A selected review of vortex identification methods with applications

Y Zhang, X Qiu, F Chen, K Liu, X Dong, C Liu - Journal of Hydrodynamics, 2018 - Springer
In the present review, recent progress on the vortex identification methods are introduced
with a focus on the newly proposed omega method (Ω method). The advantages of Ω …

Nonlinear dynamics of acoustic bubbles excited by their pressure-dependent subharmonic resonance frequency: influence of the pressure amplitude, frequency …

AJ Sojahrood, R Earl, H Haghi, Q Li, TM Porter… - Nonlinear …, 2021 - Springer
Nonlinear behavior of bubbles, and most importantly 1 2 1 2-order subharmonics (SH), are
used to increase the contrast-to-tissue ratio (CTR) in diagnostic ultrasound (US) and to …

Classification of the major nonlinear regimes of oscillations, oscillation properties, and mechanisms of wave energy dissipation in the nonlinear oscillations of coated …

AJ Sojahrood, H Haghi, R Karshafian, MC Kolios - Physics of Fluids, 2021 - pubs.aip.org
Acoustic waves are dissipated when they pass through bubbly media. Dissipation by
bubbles takes place through thermal damping (Td), radiation damping (Rd), and damping …

[HTML][HTML] Nonlinear dynamics and bifurcation structure of ultrasonically excited lipid coated microbubbles

AJ Sojahrood, H Haghi, R Karshafian… - Ultrasonics Sonochemistry, 2021 - Elsevier
In many applications, microbubbles (MBs) are encapsulated by a lipid coating to increase
their stability. However, the complex behavior of the lipid coating including buckling and …

[HTML][HTML] Collective nonlinear behavior of interacting polydisperse microbubble clusters

H Haghi, AJ Sojahrood, MC Kolios - Ultrasonics sonochemistry, 2019 - Elsevier
Acoustically excited microbubbles (MBs) have shown to exhibit rich dynamics, enabling
them to be employed in various applications ranging from chemistry to medicine. Exploiting …

Experimental and numerical evidence of intensified non-linearity at the microscale: The lipid coated acoustic bubble

AJ Sojahrood, H Haghi, TM Porter, R Karshafian… - Physics of …, 2021 - pubs.aip.org
A lipid coated bubble (LCB) oscillator is a very interesting non-smooth oscillator with many
important applications ranging from industry and chemistry to medicine. However, due to the …

[HTML][HTML] GPU accelerated numerical investigation of the spherical stability of an acoustic cavitation bubble excited by dual-frequency

K Klapcsik - Ultrasonics Sonochemistry, 2021 - Elsevier
The spherical stability of an acoustic cavitation bubble under dual-frequency excitation is
investigated numerically. The radial dynamics is described by the Keller–Miksis equation …

[HTML][HTML] Investigation of the 1/2 order subharmonic emissions of the period-2 oscillations of an ultrasonically excited bubble

AJ Sojahrood, R Earl, MC Kolios, R Karshafian - Physics Letters A, 2020 - Elsevier
In this work, through applying a comprehensive bifurcation analysis method, we study the
nonlinear radial oscillations of the bubble oscillator. The frequency of the driving force is …

Nonlinear breathing motions and instabilities of a pressure-loaded spherical hyperelastic membrane

RM Soares, PFT Amaral, FMA Silva, PB Gonçalves - Nonlinear Dynamics, 2020 - Springer
This work presents the mathematical modeling, based on a variational formulation, for the
analysis of the nonlinear static and dynamic breathing motions of a hyperelastic spherical …

[HTML][HTML] A simple method to analyze the super-harmonic and ultra-harmonic behavior of the acoustically excited bubble oscillator

AJ Sojahrood, D Wegierak, H Haghi, R Karshfian… - Ultrasonics …, 2019 - Elsevier
The bubble oscillator is a highly nonlinear system, which makes it difficult to generate a
comprehensive understanding of its oscillatory behavior. One method used to investigate …