Review
Mechanics
Detlef Lohse
Summary: This review provides an overview of the fluid dynamics of inkjet printing and discusses the main challenges for present and future research. The challenges on the printhead side include the flow inside the printhead, bubble entrainment, meniscus dynamics, wetting phenomena, and jet formation. On the receiving substrate side, challenges include droplet impact, merging, wetting, evaporation, and drying. Optimizing the process and materials as a whole is crucial for achieving efficient inkjet printing.
ANNUAL REVIEW OF FLUID MECHANICS
(2022)
Review
Mechanics
Peter J. Schmid
Summary: Dynamic mode decomposition (DMD) is a technique for factorization and dimensionality reduction of data sequences, which simplifies complex evolution processes to their dominant features and essential components. It has been widely applied in various fields beyond fluid dynamics as well.
ANNUAL REVIEW OF FLUID MECHANICS
(2022)
Review
Mechanics
Luca Brandt, Filippo Coletti
Summary: This review discusses the recent progress in understanding the physics of particle-laden turbulence, focusing on spherical particles in homogeneous and wall-bounded flows. The analysis of recent data suggests that conclusions from zero gravity conditions cannot be generalized, and the particle response time alone is insufficient to characterize the dynamics of finite-size particles. Further studies are needed to bridge the gap between dilute and concentrated conditions, and to explore the fluid dynamics of suspensions with theoretical tools accounting for both phases.
ANNUAL REVIEW OF FLUID MECHANICS
(2022)
Article
Mathematics, Applied
Si-Jia Chen, Xing Lu
Summary: Based on the test function method, this paper presents the necessary and sufficient conditions for deriving lump solutions to special types of (3+1)-dimensional nonlinear evolution equations. Two approaches to construct lump multi-kink solutions are proposed. The existence of lump solutions and lump-multi-kink solutions is illustrated with examples. These methods are of significance for studying the existence of lump solutions and mixed solutions.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2022)
Article
Mathematics, Applied
Changjin Xu, Dan Mu, Zixin Liu, Yicheng Pang, Maoxin Liao, Chaouki Aouiti
Summary: Delay has a significant impact on the dynamics of neural networks, making it a hot topic in mathematics and engineering. This paper presents a new fractional-order 4D neural network model with two different time delays based on previous research. The existence, uniqueness, and boundedness of the solution are analyzed using contraction mapping principle and the construction of an adaptive function. The stability and emergence of Hopf bifurcation are explored using the stability and bifurcation theory of fractional-order dynamical system. Novel stability criteria and bifurcation conditions are established for different delay cases. The impact of delay on stabilizing neural networks and controlling the emergence of Hopf bifurcation is thoroughly investigated, and Matlab simulations confirm the scientific validity of the derived conclusions.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2023)
Article
Mathematics, Applied
Wen-Xiu Ma
Summary: This study proposes a nonlocal real reverse-spacetime integrable hierarchies of PT symmetric matrix AKNS equations, achieved through nonlocal symmetry reductions on the potential matrix, to determine generalized Jost solutions. By applying the Sokhotski-Plemelj formula, the associated Riemann-Hilbert problems are transformed into integral equations of Gelfand-Levitan-Marchenko type. The Riemann-Hilbert problems corresponding to the reflectionless case are explicitly solved, presenting soliton solutions for the resulting nonlocal real reverse-spacetime integrable PT-symmetric matrix AKNS equations.
PHYSICA D-NONLINEAR PHENOMENA
(2022)
Article
Physics, Fluids & Plasmas
A. B. Zylstra, A. L. Kritcher, O. A. Hurricane, D. A. Callahan, J. E. Ralph, D. T. Casey, A. Pak, O. L. Landen, B. Bachmann, K. L. Baker, L. Berzak Hopkins, S. D. Bhandarkar, J. Biener, R. M. Bionta, N. W. Birge, T. Braun, T. M. Briggs, P. M. Celliers, H. Chen, C. Choate, D. S. Clark, L. Divol, T. Doppner, D. Fittinghoff, M. J. Edwards, M. Gatu Johnson, N. Gharibyan, S. Haan, K. D. Hahn, E. Hartouni, D. E. Hinkel, D. D. Ho, M. Hohenberger, J. P. Holder, H. Huang, N. Izumi, J. Jeet, O. Jones, S. M. Kerr, S. F. Khan, H. Geppert Kleinrath, V. Geppert Kleinrath, C. Kong, K. M. Lamb, S. Le Pape, N. C. Lemos, J. D. Lindl, B. J. MacGowan, A. J. Mackinnon, A. G. MacPhee, E. Marley, K. Meaney, M. Millot, A. S. Moore, K. Newman, J-M G. Di Nicola, A. Nikroo, R. Nora, P. K. Patel, N. G. Rice, M. S. Rubery, J. Sater, D. J. Schlossberg, S. M. Sepke, K. Sequoia, S. J. Shin, M. Stadermann, S. Stoupin, D. J. Strozzi, C. A. Thomas, R. Tommasini, C. Trosseille, E. R. Tubman, P. L. Volegov, C. R. Weber, C. Wild, D. T. Woods, S. T. Yang, C. Young
Summary: On August 8, 2021, an inertial fusion implosion on the National Ignition Facility achieved a fusion yield of over a megajoule and met Lawson's criterion for ignition. Experimental measurements show significant improvements in burn rate and hot-spot conditions, reaching unprecedented levels in inertial fusion research.
Review
Mechanics
Luc Deike
Summary: Breaking waves have a significant impact on the climate system by influencing the transfer of energy, momentum, and mass between the ocean and atmosphere. This article explores the importance of drops and bubbles generated by breaking waves and discusses recent progress in understanding the processes involved. It also proposes a pathway towards mechanistic parameterizations that account for the effects of sea state.
ANNUAL REVIEW OF FLUID MECHANICS
(2022)
Article
Mathematics, Applied
Yunfei Liu, Zhaoye Qin, Fulei Chu
Summary: This article presents a coupled nonlinear modeling approach to investigate the nonlinear forced vibrations in composite cylindrical shells. By numerical simulations, the effects of external temperature change, magnetic potential, electric potential, and excitation amplitude on vibration response were evaluated.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2022)
Article
Mechanics
Hamidreza Eivazi, Mojtaba Tahani, Philipp Schlatter, Ricardo Vinuesa
Summary: This article introduces the application of Physics-informed neural networks (PINNs) in solving and identifying partial differential equations. By applying PINNs to solve boundary layer problems of the Navier-Stokes equations and simulate various turbulent flow cases, it is demonstrated that PINNs have good applicability for both laminar and turbulent flows.
Article
Mechanics
Dan Zhao, Yiheng Guan
Summary: Self-excited thermoacoustic instabilities are frequently observed in rocket motors, gas turbines, ramjets, and aeroengine afterburners, which are highly detrimental and undesirable for engine manufacturers. This study predicts and characterizes modal growth behaviors in the presence of transverse and longitudinal combustion instabilities through thermoacoustic dynamics coupling studies. The derived maximum growth rate is experimentally confirmed to be greater than the practical measurements, and a phase drift is observed. The effects of variables such as the interaction index, time-delay, specific heat ratio, and acoustic losses/damping are examined.
Article
Mechanics
Hongping Wang, Yi Liu, Shizhao Wang
Summary: This study proposes a physics-informed neural network (PINN) method to reconstruct dense velocity fields from sparse experimental data. The performance of PINN is investigated in different cases, showing great potential in improving velocity resolution and predicting pressure fields.
Article
Mechanics
A-Man Zhang, Shi-Min Li, Pu Cui, Shuai Li, Yun-Long Liu
Summary: In this study, we proposed a novel theory for the dynamics of oscillating bubbles. This theory takes into consideration various factors such as boundaries, bubble interaction, ambient flow field, gravity, bubble migration, fluid properties, and surface tension. We validated the theory with experimental data and compared it with classical theoretical models, demonstrating its advantages. Additionally, we applied the theory to model complex multi-cycle bubble interaction and gained new insights into inter-bubble energy transfer and pressure wave coupling.
Article
Mechanics
Yuze Sun, Dan Zhao, Chenzhen Ji, Tong Zhu, Zhuming Rao, Bing Wang
Summary: This study explores the generation and mitigation mechanisms of self-excited pulsating oscillations in combustion systems with reduced greenhouse gases and nitrogen oxides emissions. Numerical simulations and physical analysis suggest that the use of an outlet nozzle can attenuate fuel fraction fluctuations, process vortices, and modify the temperature field, thus reducing the adverse effects of pulsating combustion.
Article
Mechanics
Shumin Liu, Haitao Sun, Dongming Zhang, Kun Yang, Dengke Wang, Xuelong Li, Kun Long, Yaning Li
Summary: Liquid nitrogen cold soaking is an innovative technology for stimulating coalbed methane, which can increase the permeability of coal seam by producing more fractures in the coal body. This study conducted nuclear magnetic resonance tests on coal samples treated with liquid nitrogen cold soaking and investigated its influence on the pore structures of coal. The results showed that liquid nitrogen cold soaking improved pore connectivity and increased the size and number of coal pore structures. The porosity and permeability of coal samples increased with the number of liquid nitrogen cold soaking cycles.
Article
Mechanics
Guangyao Rong, Miao Cheng, Zhaohua Sheng, Xiangyang Liu, Yunzhen Zhang, Jianping Wang
Summary: This study investigates the counter-rotating shock wave and wave direction control in a hollow rotating detonation combustor with a Laval nozzle. The phenomenon and spatial distribution of the counter-rotating shock wave in the combustor are revealed using the in-house solver BYRFoam developed on the OpenFOAM platform. The study proposes a method of controlling the wave direction by reducing the inlet total pressure, which in turn controls the intensity of the counter-rotating shock wave. The study also investigates the mechanism of wave direction control and finds a positive feedback interaction between the counter-rotating shock wave and the fresh gas, leading to the evolution of reverse detonation waves.
Article
Physics, Applied
Chenxi Man, Cheng Zhang, Haiqin Fang, Renwu Zhou, Bangdou Huang, Yuanzhong Xu, Xiaoxing Zhang, Tao Shao
Summary: In this study, a microbubble-enabled plasma reactor was developed for the production of plasma-activated water (PAW) by transferring highly reactive plasma species into liquids. The antimicrobial effects of PAW against Escherichia coli cells were investigated, and it was found that microbubble-enabled PAW at a lower temperature had the highest antimicrobial activity. The energy efficiency of reactive oxygen and nitrogen species production in PAW was also evaluated.
PLASMA PROCESSES AND POLYMERS
(2022)
Article
Physics, Fluids & Plasmas
A. L. Kritcher, A. B. Zylstra, D. A. Callahan, O. A. Hurricane, C. R. Weber, D. S. Clark, C. V. Young, J. E. Ralph, D. T. Casey, A. Pak, O. L. Landen, B. Bachmann, K. L. Baker, L. Berzak Hopkins, S. D. Bhandarkar, J. Biener, R. M. Bionta, N. W. Birge, T. Braun, T. M. Briggs, P. M. Celliers, H. Chen, C. Choate, L. Divol, T. Doeppner, D. Fittinghoff, M. J. Edwards, M. Gatu Johnson, N. Gharibyan, S. Haan, K. D. Hahn, E. Hartouni, D. E. Hinkel, D. D. Ho, M. Hohenberger, J. P. Holder, H. Huang, N. Izumi, J. Jeet, O. Jones, S. M. Kerr, S. F. Khan, H. Geppert Kleinrath, V. Geppert Kleinrath, C. Kong, K. M. Lamb, S. Le Pape, N. C. Lemos, J. D. Lindl, B. J. MacGowan, A. J. Mackinnon, A. G. MacPhee, E. V. Marley, K. Meaney, M. Millot, A. S. Moore, K. Newman, J. -M. G. Di Nicola, A. Nikroo, R. Nora, P. K. Patel, N. G. Rice, M. S. Rubery, J. Sater, D. J. Schlossberg, S. M. Sepke, K. Sequoia, S. J. Shin, M. Stadermann, S. Stoupin, D. J. Strozzi, C. A. Thomas, R. Tommasini, C. Trosseille, E. R. Tubman, P. L. Volegov, C. Wild, D. T. Woods, S. T. Yang
Summary: This article presents the design of the first igniting fusion plasma in the laboratory by Lawson's criterion, achieving 1.37 MJ of fusion energy. The design utilizes the indirect drive inertial confinement fusion approach and shows significant improvements in ignition compared to predecessor experiments.
Article
Physics, Fluids & Plasmas
Yuhai Li, Qingshun Bai, Yuheng Guan, Peng Zhang, Rongqi Shen, Lihua Lu, Hao Liu, Xiaodong Yuan, Xinxiang Miao, Wei Han, Caizhen Yao
Summary: This study successfully removed organic contaminants from the surface of large-aperture optical components using low-pressure air plasma cleaning method, without causing damage and metal contamination. After cleaning, the hydrophilicity of the films was significantly increased. These results provide a new method for removing organic contaminants from large-aperture optical components and are of great importance for improving the energy output of the ICF system.
Review
Physics, Fluids & Plasmas
G. D. Conway, A. Smolyakov, T. Ido
Summary: Geodesic acoustic modes (GAMs) are oscillatory flow phenomena observed in toroidal magnetic confinement fusion plasmas, impacting plasma confinement through various mechanisms such as velocity shearing of turbulent eddies and energy dissipation routes. Major advances have been made in measurements, theory, and numerical simulations of GAMs, contributing towards a unified understanding of their behavior and role in plasma confinement.
