Article
Chemistry, Physical
Jaideep Katuri, Alexey Snezhko, Andrey Sokolov
Summary: Acoustically powered bubble microswimmers suspended in liquid crystals can self-propel and induce topological defects, with their velocity and swimming direction controlled by the acoustic field.
Article
Acoustics
Guangzhao Zhou
Summary: The paper introduces a new model aimed at accurately and efficiently calculating the pressure variation inside a gas bubble. By manipulating the gas continuity equation, three ordinary differential equations are derived to capture the thermal behavior of an oscillating gas bubble at modest coding and computational costs.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
(2021)
Article
Chemistry, Analytical
Sumit Mohanty, Jiena Zhang, Jeffrey M. McNeill, Thom Kuenen, Frederic P. Linde, Jeroen Rouwkema, Sarthak Misra
Summary: This article introduces two bubble-powered micro-propeller designs that autonomously rotate under the excitation of sound waves, serving as both mobile microfluidic mixers and autonomous microrobots for targeted manipulation.
SENSORS AND ACTUATORS B-CHEMICAL
(2021)
Article
Acoustics
Hossein Haghi, Michael C. Kolios
Summary: This study examines the effect of bubble-bubble interactions on the resonance frequency of MB suspensions. It is found that primary delays cause spreading the resonance frequency of identical MBs within a range, where the closest MB to the acoustic source exhibits the lowest resonance frequency and the furthest MB resonates at the highest frequency. The inclusion of secondary delays also significantly affects the resonance frequency, resulting in an increase when the MBs are situated close to each other.
ULTRASONICS SONOCHEMISTRY
(2022)
Article
Physics, Applied
Yuyang Li, Xiaoming Liu, Qiang Huang, Tatsuo Arai
Summary: A noncontact rotational micromanipulation method using acoustically driven microbubble is reported in this study, allowing trapping and rotating micro-objects at the microscale. The rotation frequency can be controlled over a broad range by adjusting the frequency and voltage of the sinusoidal wave applied to the piezoelectric transducer.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Analytical
Brandon Hayes, Lawrence Smith, Heiko Kabutz, Austin C. Hayes, Gregory L. Whiting, Kaushik Jayaram, Robert MacCurdy
Summary: Thermal bubble-driven micro-pumps are actuation technology that can displace fluid without any moving parts. This study presents a low-cost approach using commercial substrates and tooling to accelerate the research and development of thermal bubble-driven micro-pumps.
Review
Thermodynamics
Biao Wang, Yanwei Hu, Yurong He, Nikolay Rodionov, Jiaqi Zhu
Summary: This review investigates the dynamic instabilities of gas-liquid two-phase flow boiling in micro-channels from both theoretical and experimental perspectives. Various methods to suppress instabilities are summarized, and further research directions are proposed. Experimental evidence is provided for three primary dynamic instabilities in micro-channels, and the effects of instabilities on flow pattern and heat transfer coefficient are discussed.
APPLIED THERMAL ENGINEERING
(2022)
Article
Acoustics
Peter Kalmar, Ferenc Hegedus, Daniel Nagy, Levente Sandor, Kalman Klapcsik
Summary: A fixed-point iteration technique is proposed to handle the implicit nature of the governing equations for nonlinear surface mode oscillations of acoustically excited microbubbles. The technique achieves highly accurate results with only a single reevaluation, making it a viable alternative for high-performance GPU computations. It extends the classic Keller-Miksis equation and the linearized dynamical equations for each surface mode.
ULTRASONICS SONOCHEMISTRY
(2023)
Review
Chemistry, Multidisciplinary
Huaijuan Zhou, Carmen C. Mayorga-Martinez, Salvador Pane, Li Zhang, Martin Pumera
Summary: Magnetic micro/nanorobots can be manipulated and guided in different fluid environments using magnetic fields, offering advantages such as remote control, reconfigurability, and fuel-free operation. They have diverse applications in targeted drug delivery, biofilm disruption, and environmental remediation.
Article
Mechanics
Vikash Pandey, Dhrubaditya Mitra, Prasad Perlekar
Summary: A direct numerical simulation study of buoyancy-driven bubbly flows in the presence of large-scale driving that generates turbulence reveals that increasing turbulence intensity leads to more curved bubble trajectories and decreased average rise velocity. The energy spectrum of the flow exhibits pseudo-turbulence scaling for small length scales and Kolmogorov scaling for larger scales. A scale-by-scale energy budget analysis helps understand the scaling behavior seen in the spectrum, with statistical properties consistent with experiments on turbulence modulation by air bubbles in water despite the weak buoyancy of the bubbles.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Acoustics
Hao Wu, Hao Zheng, Yuanyuan Li, Claus-Dieter Ohl, Haixia Yu, Dachao Li
Summary: This study investigates the effect of liquid surface tension on the dynamics of acoustic cavitation bubbles, revealing that low surface tension reduces bubble stability, leading to earlier collapse and farther distance from a rigid wall. Additionally, surface tension influences micro-jet speeds, highlighting the role of surfactants in optimizing acoustic cavitation.
ULTRASONICS SONOCHEMISTRY
(2021)
Article
Acoustics
Yuzhe Fan, Haisen Li, Daniel Fuster
Summary: This study discusses the effects of compressibility on the dynamics of acoustically excited bubbly screens, revealing differences between infinite and finite bubbly screens in linear and nonlinear regimes. It shows how boundaries and crystal structures can lead to local resonances and periodic structures, impacting the effectiveness of the effective medium theory (EMT). The study also highlights the importance of time delays in the nonlinear regime and identifies optimal distances for subharmonic emission in crystal structures.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
(2021)
Article
Acoustics
Dui Qin, Qianru Yang, Shuang Lei, Jia Fu, Xiaojuan Ji, Xiuxin Wang
Summary: The cavitation dynamics of a two-bubble system in viscoelastic media excited by dual-frequency ultrasound, as well as the effects of inter-bubble interactions, have been studied numerically. The results show that the interaction effects on the amplitude and nonlinearity of the bubble oscillations can be either enhanced or suppressed compared to isolated bubble cases. The study provides insights into the complex dynamic behaviors of interacting cavitation bubbles in viscoelastic tissues, which is important for cavitation-mediated biomedical applications using dual-frequency ultrasound.
ULTRASONICS SONOCHEMISTRY
(2023)
Article
Physics, Fluids & Plasmas
Konstantin Leonov, Iskander Akhatov
Summary: The dynamics of a single cavitation bubble in a spherical liquid cell surrounded by an infinite elastic solid is influenced by volume confinement, with cavitation being completely suppressed at liquid cell sizes smaller than a critical size. The study derives a system of equations for the dynamics of a confined bubble, considering various factors, and conducts linear and nonlinear analysis to determine the dynamic response.
Article
Multidisciplinary Sciences
Alvin Modin, Matan Yah Ben Zion, Paul M. Chaikin
Summary: Researchers have developed a new active system that allows for the free rotation of micro-rotors while observing the interplay of rotation and translation. Using a non-tweezing circularly polarized beam, they were able to rotate hundreds of birefringent colloids and observe the orbiting of neighboring particles with different angular velocities. They also derived an analytical model to explain the observed dynamics.
NATURE COMMUNICATIONS
(2023)
Article
Thermodynamics
Yi Zhang, Thilhara Tennakoon, Yin Hoi Chan, Ka Chung Chan, Sau Chung Fu, Chi Yan Tso, Kin Man Yu, Bao Ling Huang, Shu Huai Yao, Hui He Qiu, Christopher Y. H. Chao
Summary: The study proposes a passive hybrid system involving thermochromic smart windows and radiative coolers, showing potential in energy savings. Among cities with various climates, thermochromic smart windows and radiative coolers perform best in cities where cooling demand is significant.
Article
Mechanics
Di Liu, Csaba Hefler, Wei Shyy, Huihe Qiu
Summary: This work presents a passive mechanism that can mimic the wing motion of dragonflies, and compares the flow fields and pitching angle variations between naturally actuated wings and artificially actuated wings. The findings show that passive rotation dominates most of the wing flapping cycle, with muscle movement used for accelerating wing rotation during the upstroke reversal.
Article
Engineering, Multidisciplinary
Tianrun Gao, Huihe Qiu, Lin Fu
Summary: In this study, a novel Block-based Adaptive Particle Refinement (BAPR) method is developed, which is able to provide necessary local refinement flexibly for any targeted characteristic and track it adaptively. The activation status of the block array in BAPR defines the refinement regions, and a regularization method is used to ensure an isotropic distribution of the generated particles.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2022)
Article
Thermodynamics
Shengxian Huang, Huihe Qiu, Ying Wang
Summary: This study proposes a new bionic method to improve the wind energy utilization of wind turbines while strictly controlling the aerodynamic noise and load level of the blades. Two novel dolphin-inspired airfoil profiles are developed and analyzed for their aerodynamic performance and noise characteristics. Additionally, two 3D bionic blades suitable for NREL phase VI HAWT are established and compared based on their low-speed shaft torque and blade root bending moment. The research results provide valuable insights for optimizing energy efficiency and noise reduction in wind turbines.
ENERGY CONVERSION AND MANAGEMENT
(2022)
Review
Thermodynamics
Yin Hoi Chan, Yi Zhang, Thilhara Tennakoon, Sau Chung Fu, Ka Chung Chan, Chi Yan Tso, Kin Man Yu, Man Pun Wan, Bao Ling Huang, Shuhuai Yao, Hui He Qiu, Christopher Yu Hang Chao
Summary: Buildings absorb solar radiation, leading to energy wastage. The climate crisis has driven research in passive cooling technologies. Thermochromic smart windows, daytime radiative coolers, and reflective paints are three prominent technologies.
ENERGY CONVERSION AND MANAGEMENT
(2022)
Article
Engineering, Biomedical
Chengcheng Li, Huihe Qiu, Jianying Ma, Ying Wang
Summary: This study proposes a centrifugal blood pump with superhydrophobic characteristics to reduce blood damage and optimize hydraulic performance. By simulating the slip characteristics of superhydrophobic surfaces and applying them to the blood pump model, it is found that the superhydrophobic surface can significantly reduce shear stress, improve hydraulic efficiency, and reduce hemolysis in the blood pump.
INTERNATIONAL JOURNAL OF ARTIFICIAL ORGANS
(2022)
Article
Chemistry, Multidisciplinary
Christopher Salmean, Huihe Qiu
Summary: Flow boiling is a promising method for cooling sensitive components. In this study, the researchers discovered that using nanostructures can control the coalescence and flow interactions of bubbles, leading to enhanced heat transfer efficiency.
Article
Thermodynamics
Yinchuang Yang, Jian Li, Xin Ye, Huihe Qiu
Summary: This study investigates the effect of wettability-patterned micro/nanostructures on the thermal performance of an ultrathin vapor chamber (UTVC). It is found that the wettability-patterned surface enhances the evaporation process by increasing the length of the triple contact line. The UTVC with the wettability-patterned surface achieves a significant improvement in thermal conductivity and thermal resistance.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
F. R. Siddiqui, C. Y. Tso, H. H. Qiu, Christopher Y. H. Chao, S. C. Fu
Summary: Droplet phase change plays a crucial role in achieving high heat transfer rates, and the copper-alumina hybrid nanofluid (CAHF) demonstrates better evaporation performance and heat transfer efficiency in thermal management.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Computer Science, Interdisciplinary Applications
Tianrun Gao, Huihe Qiu, Lin Fu
Summary: Fluid-Structure Interaction (FSI) is a critical problem in ocean engineering, and the smoothed particle hydrodynamics (SPH) method has been employed for FSI problems due to its advantages in handling multi-physics problems. The Adaptive Particle Refinement (APR) method can improve the efficiency of SPH, and this study further improves the APR method by developing new algorithms. The improved APR method with a large refinement scale ratio and a new free-surface detection strategy demonstrates great potential in efficiently and accurately simulating complex FSI problems.
JOURNAL OF COMPUTATIONAL PHYSICS
(2023)
Article
Nanoscience & Nanotechnology
Christopher Salmean, Huihe Qiu
Summary: This study investigates the enhancement of flow boiling by manipulating wettability patterns and contact-line pinning. Two main principles for enhancing boiling heat transfer are identified: the interaction between the local contact angle and the bubble's tilt influences the ease of bubble departure from superhydrophobic patches, and ring-shaped superhydrophobic patches can trap droplets inside the forming bubbles, supplementing the heat transfer coefficient and critical heat flux. By applying these principles, the heat transfer coefficient and critical heat flux of heterogeneous surfaces were improved by 62% and 24%, respectively. A general model to estimate the ease of bubble departure using geometric arguments is established and validated.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Huihe Qiu, Ruo Peng Zhang, Mei Mei
Summary: This paper investigates the enhancement of wicking rates by using pillar array structures with nonuniform pillar height levels. Experimental results show that a nonuniform pillar height structure leads to a separation of layers in the liquid spreading process, resulting in a significant increase in the wicking rate for all tested liquids. A theoretical model is developed to explain and predict this enhancement effect.
Article
Materials Science, Biomaterials
Pei Zhang, Dong Liao, Hongyu Yu, Huihe Qiu
Summary: This paper proposes a novel metabolic rate measurement model using wearable technology to accurately identify and predict human metabolism values. The experimental results validate the linear relationship between the proposed model and the tested metabolic rate, as well as the applicability of the model across different temperatures and a wider metabolic range.
ACS BIOMATERIALS SCIENCE & ENGINEERING
(2023)
Article
Thermodynamics
Siru Chen, Aiqiang Pan, Yihao Zhu, Tsz Chung Ho, Hau Him Lee, Yijun Zeng, Chili Wu, Huihe Qiu, Chi Yan Tso
Summary: A novel composite adsorbent coated superhydrophilic-nanostructured heterogeneous surface is proposed to enhance condensation heat transfer. The results show that the heterogeneous surfaces with vertical middle-stripe patterns of the composite adsorbent have better condensation heat transfer performance compared to other patterns. The water film formed on the superhydrophilic region can be adsorbed by the adjacent composite adsorbent, leading to an enhancement in heat transfer performance.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Thermodynamics
Farooq Riaz Siddiqui, Chi-Yan Tso, Huihe Qiu, Christopher Y. H. Chao, Sau Chung Fu
Summary: In recent years, heat dissipation in high heat flux devices has increased significantly, and it is expected to reach unprecedented levels in future devices. Current research focuses on the spray cooling performance and effects of a hybrid nanofluid, a thermal fluid for addressing heat dissipation issues. The results show that using hybrid nanofluid spray cooling can enhance the critical heat flux up to 126% compared to water spray cooling. This enhancement is attributed to the high latent heat of vaporization and residue wetting and wicking effects of the hybrid nanofluid.
APPLIED THERMAL ENGINEERING
(2022)
