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
Mechanics
Manolia Andredaki, Anastasios Georgoulas, Nicolas Miche, Marco Marengo
Summary: In this study, an enhanced Volume of Fluid model is used for parametric numerical simulations to investigate breakup phenomena of accelerating, elongated vapor bubbles in circular mini-channels. The effect of fundamental controlling parameters on breakup characteristics is examined, leading to the identification of three prevailing regimes: full breakup, partial breakup, and no breakup. The results are consolidated into a well-defined flow map based on the We and Fr* numbers.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2021)
Article
Engineering, Chemical
Simon Wachter, Tobias Jakobs, Thomas Kolb
Summary: The study compared three different nozzle flow configurations and found that liquid sheet configurations resulted in smaller droplet sizes compared to liquid jet configuration. A nozzle with identical orifice areas was used in experiments to ensure constant velocities and momentum flows. The influence of gas velocity, dynamic viscosity of the liquid, and nozzle configuration on droplet sizes and primary breakup was investigated.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2021)
Article
Mechanics
Wai Hong Ronald Chan, Perry L. Johnson, Parviz Moin, Javier Urzay
Summary: The study examines the evolution of bubble size distribution during breaking waves, identifying distinct characteristics in different intervals. The first interval shows stable bubble mass flux and supports theoretical analysis, while the second interval sees an increase in bubble mass flux and power-law exponent for size distribution. Different physical mechanisms emerge during different phases of breaking-wave evolution, with size-local break-up remaining a dominant theme. Parts 1 and 2 provide an analytical toolkit for population balance analysis in two-phase flows.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Chemistry, Multidisciplinary
Ryuichi Fujita, Shoko Yoshida, Haruka Kano, Kyohei Matsuo, Hironobu Hayashi, Hiroko Yamada, Naoki Aratani
Summary: In this study, a stable and soluble hexarylene compound was successfully synthesized through an oxidative fusion reaction. The compound showed a sharp peak at 831 nm in the absorption spectrum and exhibited stability under ambient conditions, making it a potential material for near-infrared applications.
CHINESE JOURNAL OF CHEMISTRY
(2023)
Article
Mathematics, Interdisciplinary Applications
S. Geara, S. Martin, S. Adami, J. Allenou, B. Stepnik, O. Bonnefoy
Summary: This article presents a study on improving the control of liquid jet break-up by applying external vibrations using a simple numerical method. The method is based on a weakly compressible SPH approach and an improved geometrical method for density calculation near the free surface. The simulation results show accurate representation of the jet break-up phenomenon, indicating a step forward in simulating liquid atomization in industrial conditions with the SPH method.
COMPUTATIONAL PARTICLE MECHANICS
(2023)
Article
Chemistry, Physical
Mamiko Nakabayashi, Kazutaka Nishiguchi, Xizhuang Liang, Takashi Hisatomi, Tsuyoshi Takata, Takashi Tsuchimochi, Naoya Shibata, Kazunari Domen, Seiichiro L. Ten-no
Summary: Layered perovskite Y2Ti2O5S2 is a promising semiconductor photocatalyst for overall water splitting under visible light due to its suitable electronic structure. However, controlling structural defects during synthesis is crucial. Transmission electron microscopy revealed large planar defects composed of S-Mg-S layers in Y2Ti2O5S2 synthesized by the flux method. First-principles calculations based on density functional theory were used to determine the structure and electronic properties of the planar defects. Evaluation of the formation energy indicated that S- and Mg-poor conditions could prevent defect formation. Furthermore, the impurity levels caused by the planar defects and their impact on the electronic state and catalytic performance were discussed.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Marta I. Hernandez, Massimiliano Bartolomei, Jose Campos-Martinez
Summary: This study reports accurate quantum calculations of Helium atom sieving by two-dimensional graphtriyne layers with a new interaction potential. Despite expectations of limited quantum effects due to larger pore size compared to graphdiyne, strong quantum behavior was observed, attributed to selective adsorption resonances with a pronounced effect in the low temperature regime. This led to selectivity at very low temperatures and more efficient crossing of the membrane by heavier isotopes.
Article
Engineering, Marine
Junde Li, Alexander Babanin, Qingxiang Liu, Joey J. Voermans, Petra Heil, Youmin Tang
Summary: The study demonstrates that wave-induced sea ice break-up increases sea ice concentration and thickness in some Arctic seas during the ice growth season but accelerates sea ice melt in other seas during summer. In addition, wave-induced mixing can slow the sea ice formation in winter and the melt in summer by exchanging heat fluxes. The findings highlight the positive impact of wave-induced sea ice break-up on improving sea ice simulations and suggest important implications for future model development.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2021)
Article
Mechanics
Peng-Jun-Yi Zhang, Zhen-Hua Wan, De-Jun Sun
Summary: Nonlinearity plays a vital role in jet noise modeling, and current modeling approaches have made some progress. However, a more physics-based and generalized nonlinear model is still required.
Article
Thermodynamics
Guofu Sun, Yi Zhan, Tomio Okawa, Mitsuhiro Aoyagi, Akihiro Uchibori, Yasushi Okano
Summary: Experiments were conducted on liquid jets ejected from oval nozzles to investigate the effects of nozzle orifice shape on jet behavior. The study found that the liquid jet exhibited different characteristics at different liquid flow rates. Correlations were established to predict the liquid jet state and characteristics of the secondary droplets produced during jet impact onto a solid surface. This research extended the available knowledge on liquid jet behavior.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Oceanography
J. Kousal, J. J. Voermans, Q. Liu, P. Heil, A. Babanin
Summary: Waves and sea ice are closely coupled, with wave-induced ice break-up regulating air-sea interaction and sea ice growth/melt. This coupling is often neglected in modeling the polar climate system.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Mechanics
E. Antonopoulou, O. G. Harlen, M. Rump, T. Segers, M. A. Walkley
Summary: The study investigated the impact of surfactants on inkjet printing, revealing that rapid jetting processes result in concentration gradients of surfactants and delay or prevent the separation between the head drop and the ligament, thereby inhibiting the formation of satellite drops.
Article
Mechanics
Si Kasmaiee, M. Tadjfar
Summary: The influence of changing the injection angle of a liquid jet injected into airstream in crossflow was investigated. Different breakup regimes occur based on the relative importance of the aerodynamic forces of the crossflow to the liquid momentum and surface tension forces. The behavior of the liquid jet penetration into the airstream varies with the injection angle and gas Weber number.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2022)
Article
Chemistry, Physical
Asylbek A. A. Zhanserkeev, Emily Y. L. Yang, Ryan P. P. Steele
Summary: Ab initio computersimulations of anharmonicvibrationalspectra provide detailed understanding of molecular and complex vibrational behavior. The generation of mode-coupling potentials is the computational bottleneck in such simulations, which can be addressed using a combination of local-mode representation and multilevel methods. By predicting pairwise couplings at a low level of quantum chemistry and recycling excluded pairs at a low level of theory, accurate vibrational self-consistent field calculations can be achieved. Distance-based truncation of low-level predictions further improves computational efficiency without significant loss of accuracy. This combined approach shows promising results in test cases and has potential for accelerating larger systems and higher-order couplings.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Green & Sustainable Science & Technology
Islam Kabil, Mansour Al Qubeissi, Jihad Badra, Walid Abdelghaffar, Yehia Eldrainy, Sergei S. Sazhin, Hong G. Im, Ahmed Elwardany
Summary: An improved heating and evaporation model for fuel droplets was implemented in the commercial CFD software CONVERGE, showing better agreement with experimental data compared to the built-in model. The new model was validated for single droplet and hollow-cone spray simulations, as well as full-cycle engine simulations using PRF65 fuel. The importance of accurately modeling droplet heating and evaporation processes for predicting PPCI engine performance was highlighted.
Article
Energy & Fuels
D. Antonov, P. A. Strizhak, R. M. Fedorenko, Z. Nissar, S. S. Sazhin
Summary: This paper experimentally investigates puffing and micro-explosions in composite water/rapeseed oil droplets in the presence of lignite and bituminous coal micro-particles. It was found that the time to puffing/micro-explosion and the average radii of child droplets decrease with increasing gas temperature. The presence of bituminous coal leads to a visible decrease in these radii.
Article
Thermodynamics
S. S. Sazhin, E. Shchepakina, V. A. Sobolev, D. Antonov, P. A. Strizhak
Summary: A new simple model is proposed for the puffing and micro-explosion of composite multi-component water/liquid fuel droplets. The model takes into account the effects of droplet thermal swelling and uses analytical methods to analyze droplet heating and evaporation. The results show that the model can reasonably predict the times of puffing and micro-explosion, which are influenced by ambient gas temperatures and initial droplet radii. Furthermore, considering the presence of multiple components in the fuel leads to longer times to puffing and micro-explosion.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
R. M. Fedorenko, D. V. Antonov, P. A. Strizhak, S. S. Sazhin
Summary: This study investigates the puffing and micro-explosion processes in composite water/fuel droplets (kerosene, Diesel fuel, and rapeseed oil) through experimental and numerical methods. The experiments were conducted in quiescent air at atmospheric pressure with natural convection. The results show that the time to puffing/micro-explosion decreases with increasing ambient temperature and increases with increasing initial droplet radii for all three fuels. The observed longer time for rapeseed oil droplets compared to the predicted time is attributed to the formation of bubbles, which is not considered in the model used in the analysis.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Mechanics
S. Tonini, G. E. Cossali, E. A. Shchepakina, V. A. Sobolev, S. S. Sazhin
Summary: This paper revisits a previously developed model for mono-component droplet evaporation and analyzes it using new mathematical tools. The study finds that the correction factor has a significant impact on the evaporation rate for small droplets evaporating at low pressure, while it has a small effect on the evaporation rate for large droplets evaporating at atmospheric and higher pressures.
Article
Physics, Fluids & Plasmas
Matthew R. Turner, Richard P. Sear
Summary: The Earth's atmosphere contains suspended particles, which may deviate from the air's path and collide with obstacles. Particle inertia, measured by the Stokes number St, drives this deposition, with a critical value Stc. The deposition amount near Stc follows an unusual scaling law of exp[-1/(St - Stc)1/2], controlled by the flow's stagnation point.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Thermodynamics
Mario H. Morales, Konstantin D. Tsapenkov, Ivan A. Zubrilin, Denis V. Yakushkin, Alexander S. Semenikhin, Sergei S. Sazhin, Sergei G. Matveev
Summary: The aim of this work is to develop surrogates for hydrocarbon fuels by considering their atomization, heating, evaporation, and combustion behaviors. Three diesel surrogates and a kerosene surrogate were successfully formulated using this approach. The physicochemical properties of individual hydrocarbons and their mixtures were calculated with an accuracy within 3% of experimental data. Comparative studies between one of the diesel surrogates and diesel fuel demonstrate a good match in properties. This approach proves suitable for formulating surrogates for both kerosene and diesel fuel.
COMBUSTION SCIENCE AND TECHNOLOGY
(2023)
Article
Energy & Fuels
G. Castanet, D. V. Antonov, I. A. Zubrilin, P. A. Strizhak, S. S. Sazhin
Summary: The study generalizes an earlier model for predicting the onset of puffing/micro-explosion in composite multi-component water/liquid fuel droplets to consider the shifting of the water subdroplet relative to the center of the fuel droplet. The new model is validated by comparing its predictions with the previously developed numerical code and experimental data. The results show that slight shifts in the position of the water subdroplet have minimal effects on the timing of puffing/micro-explosion.
Article
Energy & Fuels
Tali Bar-Kohany, Dmitrii V. Antonov, Pavel A. Strizhak, Sergei S. Sazhin
Summary: This study investigates the influence of different factors on bubble growth and its impact on puffing and micro-explosions. It is found that the inertial regime of bubble growth is crucial for the evaluation of breakup time in micron-sized droplets.
Article
Thermodynamics
Pavel V. Skripov, Tali Bar-Kohany, Dmitrii V. Antonov, Pavel A. Strizhak, Sergei S. Sazhin
Summary: This paper critically reviews and further develops previously developed experimental methodologies for determining the nucleation temperatures of water at atmospheric pressure. Special attention is given to a methodology that regulates the experimental setup details and the procedure for translating primary data into required liquid temperatures at the onset of boiling. It is found that following this methodology leads to higher nucleation temperatures of water compared to previous predictions in certain heating rate ranges. New approximations for the nucleation temperature as a function of heating rate are suggested based on amended and revised experimental data, which are expected to have wide applications in various industries.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Physics, Fluids & Plasmas
Ryan Poole, M. R. Turner
Summary: A spatiotemporal stability analysis is conducted on a flow representing both jets and wakes, subject to confinement by identical compliant walls. The flow's absolute and convective stability properties are determined by tracking the position of pinch points in the complex wave-number plane. The compliant walls modify the existing shear-induced instabilities and introduce new instabilities, which can become dominant and induce absolute instability into the system.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Thermodynamics
Dmitrii V. Antonov, Elena A. Shchepakina, Vladimir A. Sobolev, Sergey Y. Misyura, Igor G. Donskoy, Pavel A. Strizhak, Sergei S. Sazhin
Summary: In this study, a simple model of methane dissociation from methane-hydrate particles is proposed. The model assumes that methane-hydrate particles form a porous film and are heated by ambient air convection. When the temperature of the methane-hydrate reaches the critical temperature, all methane is released and turns into ice. The model shows good agreement with experimental results at the initial stage but predicts faster methane release over time.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Mechanics
D. V. Antonov, S. Tonini, G. E. Cossali, V. V. Dolgikh, P. A. Strizhak, S. S. Sazhin
Summary: A new model for mono-component droplet heating/evaporation is developed and applied to experimental data analysis. The model combines the liquid phase model and the gas phase model to obtain explicit and implicit expressions for the Nusselt number and evaporation rate of the droplet. The model is verified and validated through comparisons with other models and experimental data, showing good agreement.
Article
Thermodynamics
Dmitrii V. Antonov, Elena A. Shchepakina, Vladimir A. Sobolev, Elena M. Starinskaya, Vladimir V. Terekhov, Pavel A. Strizhak, Sergei S. Sazhin
Summary: A new analytical solution for solving a non-linear heat transfer equation in a spherically-symmetric droplet is proposed. By approximating the thermophysical properties inside the droplet as average values, the non-linearity of the equation is considered to be weak and a solution is obtained. The accuracy of the numerical code implementing this solution is verified by comparing its predictions with those of COMSOL Multiphysics code. The results demonstrate that, under experimental conditions, there are small differences in the temperatures predicted by linear and non-linear models, but significant differences in integral characteristics.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Mathematics
A. K. Gilfanov, T. S. Zaripov, S. S. Sazhin, O. Rybdylova
Summary: A modified version of the adaptive moment inversion algorithm is proposed for the solution of QMOM and CQMOM, ensuring physically meaningful results.
LOBACHEVSKII JOURNAL OF MATHEMATICS
(2022)