Article
Engineering, Chemical
Wen Jin, Jie Xiao, Hongxian Ren, Changhui Li, Qijun Zheng, Zhenbo Tong
Summary: Impinging jet atomization is a new approach in drug delivery for inhalation therapy. Numerical simulation is used to better understand the dynamics of the impinging jet. A computational fluid dynamics model was used to simulate the atomization process, which couples the Volume of Fluid method, Discrete Phase Model, and Adaptive Mesh Refinement. The study reveals the influence of the flow field inside the nozzle on the atomization characteristics.
Article
Mechanics
Yifan Liang, Lars Christian Johansen, Mark Linne
Summary: This paper presents an experimental study on shear-based spray formation, examining the effects of air swirl and aerodynamic parameters on the morphology and breakup characteristics of the liquid jets. The study utilizes high-speed shadowgraphy and particle image velocimetry to capture the first droplet locations, breakup lengths, and flow fields. The results show that air swirl promotes the development of the jets and reduces the breakup length, while increasing aerodynamic parameters lead to shorter axial distances and radial expansion of the air flows.
Article
Mechanics
Xinxin Gao, Jianye Chen, Yinan Qiu, Yue Ding, Junlong Xie
Summary: Phase change has a significant impact on the morphology and breakup extent of droplets during atomization, which varies in the primary breakup and secondary atomization stages.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Thermodynamics
Fatih Demir, Oguz Turgut, Tamer Calisir
Summary: The flow field and heat transfer of a swirling jet under low nozzle-to-plate distances were numerically investigated using various turbulence models. The effects of Reynolds number and dimensionless nozzle-to-plate distance on the flow field and heat transfer were analyzed. The results showed that the height of the computational domain defined on the impingement plate significantly influenced the results, particularly at low nozzle-to-plate distances. The agreement between one of the cases and experimental results was observed when using the Realizable k-e turbulence model. The parametric analysis revealed that the theoretical swirl number decreased as Reynolds number increased at a constant nozzle-to-plate distance, but increased for nozzle-to-plate distances below 0.75. The pressure peaks and subatmospheric pressure on the impingement plate varied with the nozzle-to-plate distance and Reynolds number.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
Article
Mechanics
Udaysinh S. Bhapkar, Abhishek Mishra, Harekrishna Yadav, Amit Agrawal
Summary: This experimental study investigated the flow characteristics of synthetic jets emitted from different orifice shapes. The results showed that the wall jet from the elliptical orifice had higher energy-containing vortices and a delayed self-similarity compared to other orifice shapes. The elliptical orifice also had relatively higher normal and shear stresses. In addition, for a larger nozzle to surface spacing, the rectangular orifice shape resulted in a shifting of the self-similarity location.
Article
Mechanics
Naoki Horiguchi, Hiroyuki Yoshida, Akiko Kaneko, Yutaka Abe
Summary: In this study, the atomization behavior of a wall-impinging liquid jet in a shallow pool was investigated using numerical simulation and a dispersed-phase tracking method. The results revealed three patterns of droplet formation and theoretical boundaries were established using dimensionless numbers. The mechanisms of droplet formation were identified and the relationship between local behavior and overall atomization of the jet was established. This study clarifies the atomization mechanisms in the liquid film flow of a wall-impinging liquid jet in a shallow pool.
Article
Thermodynamics
Fan -Chun Hsieh, Tsing-Fa Lin
Summary: An experiment was conducted to explore the effects of disk rotation on vortex flows induced in a round jet of air impinging onto a heated horizontal disk. The results indicate that the rotation speed of the disk and the separation distance between the jet and disk have significant impacts on the vortex flows.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Physics, Fluids & Plasmas
Spencer L. Stahl, Datta Gaitonde, Vikas N. Bhargav, Farrukh S. Alvi
Summary: A theoretical model is developed to predict the aeroacoustic feedback coupling of dual impinging jets in supersonic vertical takeoff and landing aircraft, and its effectiveness is verified through experiments and numerical simulations.
PHYSICAL REVIEW FLUIDS
(2022)
Article
Physics, Fluids & Plasmas
Oliver Tolfts, Guillaume Deplus, Nathanael Machicoane
Summary: The breakup of a liquid jet by a surrounding gas jet was investigated using high-speed back-lit imaging. The focus of the study was on the time dynamics and statistics of the liquid jet length. Different inlet velocities were used to obtain a wide range of gas and liquid Reynolds numbers, gas-to-liquid dynamic pressure ratio M, and Weber number. The study covered a variety of scales and explored two breakup regimes by adapting the imaging system's spatial and temporal resolutions. The length distributions of the liquid jet were analyzed and the first two moments were found to be power laws of M, with a constant ratio. The temporal dynamics were studied using autocorrelation functions and showed that the correlation times were controlled by the gas jet, with a secondary influence of the liquid Reynolds number.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Mechanics
Yang Li, Yunhua Jiang, Le Shen, Zhihui Zou, Hanrui Wang, Mao Yang
Summary: A series of experiments were conducted to investigate the energy dissipation of a submerged water jet wrapped in an annular gas jet. The experiments were carried out in a transparent water tank under different gas ventilation rates, annular sizes, water jet nozzle diameters, and water jet velocities. By creating a ventilated cavity with the annular gas jet, the submerged water jet was enclosed and separated from the surrounding water, increasing its effective working length and reducing energy dissipation. The geometry of the ventilated cavity changed periodically, with the cavity length and diameter decreasing after reaching peak values in each cycle. The development process of the ventilated cavity was divided into formation, collapse, and intermission stages. The maximum cavity length decreased with the per unit time momentum ratio between the water jet and the gas jet, indicating that this ratio was a dominating parameter for the cavity geometry.
Article
Chemistry, Physical
Qingyun Li, Zihua Wang, Xuezhong Wang
Summary: Computational fluid dynamics (CFD) and population balance models (PBM) were combined for the first time to simulate the synthesis of zirconia nanoparticles in a self-designed confined impinging jet mixing (CJM) reactor in a continuous hydrothermal flow synthesis (CHFS) system. The hydrodynamic and thermodynamic behaviors in the CJM reactor were found to significantly affect the formation of ZrO2 nanoparticles. Crucial parameters, including velocities, temperatures, mixing conditions, and reaction rates, were analyzed under different supercritical conditions. The particle size distribution (PSD) patterns showed normal distributions in all cases, and the mean particle sizes were calculated and compared using PBM aggregation analysis.
Article
Thermodynamics
Xiangyu Zhai, Bo Yin, Nader Karimi, Vikrant Gupta, Larry K. B. Li, Yu Guan, Wen Ao
Summary: This study shows that the lift characteristics of two tandem airfoils depend on the streamwise distance. When the streamwise distance is less than 3, both the lift amplitude of the fore airfoil and the oscillation frequency of both airfoils experience abrupt decreases.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2021)
Article
Thermodynamics
Naseem Uddin, Sven Olaf Neumann, Bernhard Weigand, Bassam A. Younis
Summary: The study found that using a cylindrical insert in the impingement pipe results in enhanced heat transfer rates for cooling applications. The insert is placed just before where the jet issues from the circular pipe to passively excite the jet's velocity field. Large Eddy Simulations showed that this method can improve heat transfer performance.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Damora Rhakasywi, Harinaldi, Engkos A. Kosasih, Ridho Irwansyah
Summary: This study investigates the impinging synthetic jet produced by the continuous movement of an oscillating piezoelectric membrane to enhance heat transfer. Experimental measurements and numerical simulation were conducted to elucidate the distribution of forced convective heat transfer. The 120 Hz square wave excitation mode produces the best heat transfer value.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Mechanics
P. D. Huck, R. Osuna-Orozco, N. Machicoane, A. Aliseda
Summary: A study on a canonical co-axial round-jet two-fluid atomizer shows atomization occurring over a wide range of momentum ratios, with a critical momentum ratio of 50 separating low and high dispersion regimes. Results suggest that increasing momentum in the gas phase in the low-momentum regime leads to less droplet dispersion.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Multidisciplinary Sciences
Chunyang Yin, Shunhao Wang, Quanzhong Ren, Xinming Shen, Xiaodong Chen, Yajun Liu, Sijin Liu
Article
Computer Science, Interdisciplinary Applications
Yanxing Wang, Xiaodong Chen, Xingjian Wang, Vigor Yang
JOURNAL OF COMPUTATIONAL PHYSICS
(2019)
Article
Mechanics
Bo Wang, Chenyu Wang, Yude Yu, Xiaodong Chen
Article
Mechanics
Bo Wang, Shuai Zhang, Xiaodong Chen
Article
Chemistry, Analytical
Chun-Dong Xue, Xiao-Dong Chen, Yong-Jiang Li, Guo-Qing Hu, Tun Cao, Kai-Rong Qin
Article
Mechanics
Xiaodong Chen, Vigor Yang
Article
Nuclear Science & Technology
Zhihong Guo, Xiaodong Chen, Guoqing Hu
Summary: This study utilizes recent advancements in numerical methods to realistically model the complex fluid-structure interactions during a hypothetical core destructive accident in a sodium-cooled fast reactor. The evaluation of structural deformations and plug rises demonstrates the safety features of the container design.
NUCLEAR ENGINEERING AND TECHNOLOGY
(2022)
Article
Mechanics
Menghan Pan, Juan Lu, Wentao Wang, Xiaodong Chen, Qingquan Liu, Lanjuan Li
Summary: This study uses a coupling method of computational fluid dynamics and discrete element method to numerically investigate the fluidization dynamics of an impinging-jet-driven bioreactor. It is found that the bed expansion is proportional to the inlet flow rate and inversely proportional to the microcapsule density and size. The distribution of porosity indicates overall even fluidization, except for a dead region near the bottom periphery of the bioreactor. The interaction of microcapsules plays an essential role in the variations of the dead region.
Article
Mechanics
Qin Zhou, Xinglong Shang, Xiaodong Chen, Yanyan Chen, Guoqing Hu
Summary: Aerosols generated during common human activities or medical procedures play a vital role in the transmission of SARS-CoV-2. Tear films during non-contact intraocular pressure measurements can potentially carry the virus, posing a high risk for eye care practitioners and patients. Numerical investigations reveal that eyes with excessive tears have a greater probability of generating aerosols.
Article
Materials Science, Multidisciplinary
Shuai Zhang, Bo Wang, Chenmu Xue, Xiaodong Chen
Summary: This paper presents a reusable and adjustable microfluidic device composed of glass capillaries and polydimethylsiloxane, which allows for the generation of compound microdroplets with different morphologies. The device can be used for rapid prototyping and high-throughput generation of droplets or particles.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Mechanics
Zeyao Ma, Shuai Zhang, Bo Wang, Qingquan Liu, Xiaodong Chen
Summary: This article investigates the deformation of compound microdroplets transported inside a circular microchannel using numerical simulations. Two droplet morphologies (shell-core and Janus) are considered, and their behavior is analyzed in terms of flow rates, physical properties, and confinement conditions. The results show that the aspect ratio of the shell droplet in shell-core microdroplets decreases with the capillary number and droplet sizes, while sudden jumps occur when thin films form between the shell and core interfaces. Conversely, the aspect ratio of the core droplet in Janus microdroplets increases and then decreases with the flow and space confinements.
Article
Biochemical Research Methods
Jinghong Su, Xiaodong Chen, Yongzheng Zhu, Guoqing Hu
Summary: This study presents a fast numerical algorithm and machine learning techniques for analysis and design of inertial microfluidic devices, generating a database of inertial lift forces in straight microchannels and developing a machine learning assisted model to predict particle trajectories quickly and accurately.
Article
Nanoscience & Nanotechnology
Yingnan Sun, Xiaodong Chen, Yongxin Zheng, Yuhan Song, Huai-Rong Zhang, Shusheng Zhang
ACS APPLIED NANO MATERIALS
(2020)
Article
Mechanics
Bo Wang, Shuai Zhang, Xiaodong Chen
