Article
Mechanics
A. Krikunova, A. S. Saveliev, A. D. Cheshko
Summary: This paper shows that acoustics can increase the stability of flames under certain conditions of reverse gravity, and that there is a hysteresis in the V-M and M-V transitions under both reverse and normal gravity. The study also proves that the conditions for hysteresis degeneracy under reverse gravity are independent of the excitation frequency.
Article
Mechanics
Xiao-Yu Xu, Zheng Xu, Xiao-Dong Wang, Li-Ding Wang, Shao-Chun Qin, Jun-Shan Liu, Yu Yu
Summary: This study reports the breakup mechanism of a conical liquid bridge based on the electrostatic liquid loading method. The breakup criterion in terms of interface feature size is derived, and the mechanism is categorized as either spontaneous breakup or stretching breakup. The evolution of interface and velocity for the two breakup behaviors is investigated, and the effects of top radius and stretching velocity on remnant volume are examined.
Article
Thermodynamics
Louise da Costa Ramos, Luis Fernando Figueira da Silva, Florent Di Meglio, Valery Morgenthaler
Summary: This paper focuses on the dynamic behavior of inverted conical flames anchored on a central bluff-body. By solving species mass, momentum, and energy transport equations coupled with a methane/air chemical kinetic mechanism, the study characterizes the flame response to external velocity fluctuations. The analysis shows a trade-off between model accuracy and computational burden, with the flame response being influenced by both natural and forced behavior in different frequency ranges.
COMBUSTION THEORY AND MODELLING
(2022)
Article
Engineering, Aerospace
A. I. Krikunova, A. D. Cheshko
Summary: Ensuring fire safety is crucial in the development of habitable spacecraft. This study investigates the dynamics of an M-shaped premixed methane-air flame under normal and reversed gravity with various external acoustic excitations. The results show that low frequency acoustic excitation has minimal impact on the flame front, while at 160 Hz, oscillatory motion becomes more energetically saturated. As the frequency increases further, the dominant energy shifts back to the main gas flow, reducing its effect on the flame structure.
Article
Engineering, Aerospace
A. I. Krikunova, A. D. Cheshko, V. V. Krivets
Summary: Fire safety is crucial for the development of efficient and safe energy systems for space objects. This paper focuses on studying the influence of gravity on combustion processes and analyzes the dynamics of inverted conical methane-air flame under external acoustic excitation. The results show that at high excitation frequencies, the intensity of vortex generation is similar to that observed in experiments with normal gravity, indicating the dominance of acoustic mechanism. Additionally, at an external excitation frequency of 240 Hz, significant growth in shear vortex diameters and increased amplitude of perpendicular oscillations of flame branches were observed, indicating the most intensive large scale instability of flow.
Article
Mechanics
A. Krikunova, K. Y. Arefyev, A. S. Saveliev, G. A. Kossov, A. D. Cheshko
Summary: Experimental investigation of an inverted conical plane-symmetrical premixed methane-air flame under acoustic excitation explored transitions between different flame front configurations and the effects of acoustic disturbances. New data was obtained, revealing characteristics of hysteresis effects and their influencing factors.
Article
Chemistry, Physical
Alessandro Giannotta, Stefania Cherubini, Pietro De Palma
Summary: This article presents a conceptual study on the linear stability of a hydrogen-enriched methane-air premixed laminar flame in a cylindrical duct. The results show that adding hydrogen can reduce the flame length and affect the Flame Transfer Function (FTF) by shifting the gain drop-off towards higher frequencies and reducing the phase lag. Moreover, the addition of hydrogen can stabilize linearly unstable systems depending on the natural frequencies of the duct.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Thermodynamics
Yu Tian, Lijun Yang, Aimee S. Morgans, Jingxuan Li
Summary: This paper investigates a predictive model that considers the impact of stretch on the dynamic response of laminar premixed flames, providing insights into the effects of flame curvature and flow strain on flame height and flame transfer function.
COMBUSTION AND FLAME
(2023)
Article
Mechanics
B. Raphaldini, P. S. Peixoto, A. S. W. Teruya, C. F. M. Raupp, M. D. Bustamante
Summary: The dynamics of the Earth's atmosphere is characterized by a wide range of oscillations, from hourly to interdecadal and beyond. The precession resonance mechanism is found to play a crucial role in the generation of low-frequency oscillations and the redistribution of energy/enstrophy in turbulent systems. Efficiency peaks in energy/enstrophy transfer correspond to strong excitation of low-frequency oscillations.
Article
Chemistry, Physical
Defeng Yan, Yuhui Wang, Jiyu Liu, Danyang Zhao, Pingmei Ming, Jinlong Song
Summary: A novel method was proposed in this study to prepare conical, cylindrical, and inverted conical pillars using meniscus-confined electrochemical 3D printing. Pillar arrays with excellent superhydrophobicity were successfully fabricated on Cu substrates, enriching the theory and technology for preparing superhydrophobic pillars with variable diameters.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2021)
Article
Mechanics
Zhongyuan Ni, Fuqiang Chu, Shaokang Li, Jia Luo, Dongsheng Wen
Summary: This study investigates metastable liquid film dewetting on superhydrophobic surfaces induced by dry hole growth through a combination of experimental and theoretical analysis. It is found that the growth behavior of dry holes can lead to liquid film dewetting. Theoretical analysis reveals that the behavior of the holes is influenced by the competition between capillary force and hydrostatic pressure, and the scale of the dewetting area is affected by the Young-Laplace equation and the shape of the superhydrophobic surface.
Article
Chemistry, Physical
Yitong Xie, Chaokui Qin, Zhiguang Chen, Pengfei Duan, Shuangqian Guo
Summary: Injecting hydrogen into existing natural gas networks is a promising method to mitigate global warming, but there is insufficient evidence to determine the acceptable degree of hydrogen mixture. Experimental evaluation of burners using methane-hydrogen mixtures provided mathematical formulae for the relationships between hydrogen percentage, temperature, and flashback and lifting. An analysis method for changes in flame stability region and gas source replacement was proposed based on the limits of flashback and lifting.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Physical
Haoxin Deng, Zhifeng Yao, Guoyan Chen, Xiaoping Wen, Fahui Wang, Qiaosheng Zhang, Jianfei Dong, Mingming Huang
Summary: This study investigates the effect of laminar flame speed on flame dynamics in two-dimensional half open tubes using a two-dimensional laminar combustion model. The simulation results reveal that flame propagation similarity is only maintained during the acceleration phase, with flame tip velocity oscillation being related to the laminar flame speed. The correlation between flame surface area and the growth rate of burnt gas volume is also influenced by laminar flame speed.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Mechanics
Javed Mohd, Amar Yadav, Debopam Das
Summary: This article presents some fascinating flow features observed while cleaning or filling medicine or liquid vials, including the formation of previously unknown open inverted bell and bell-shaped flow structures.
Article
Multidisciplinary Sciences
Qi Jiang, Jinhui Tong, Yeming Xian, Ross A. Kerner, Sean P. Dunfield, Chuanxiao Xiao, Rebecca A. Scheidt, Darius Kuciauskas, Xiaoming Wang, Matthew P. Hautzinger, Robert Tirawat, Matthew C. Beard, David P. Fenning, Joseph J. Berry, Bryon W. Larson, Yanfa Yan, Kai Zhu
Summary: In this study, a reactive surface engineering approach was used to enhance the performance of perovskite solar cells with an inverted structure. The resulting p-i-n solar cells showed a high power conversion efficiency of over 25% and remained stable after long-term operation under extreme conditions.
Article
Physics, Applied
E. E. Son, A. I. Krikunova, A. S. Saveliev
Article
Physics, Applied
A. I. Krikunova, E. E. Son
Article
Engineering, Aerospace
Anastasia Krikunova, Eduard E. Son
MICROGRAVITY SCIENCE AND TECHNOLOGY
(2018)
Article
Physics, Applied
A. Krikunova
Article
Physics, Applied
K. Yu Arefyev, A. Krikunova, V. A. Panov
Article
Mechanics
A. Krikunova
Article
Engineering, Aerospace
A. Krikunova
Article
Mechanics
A. Krikunova, A. S. Saveliev, A. D. Cheshko
Summary: This paper shows that acoustics can increase the stability of flames under certain conditions of reverse gravity, and that there is a hysteresis in the V-M and M-V transitions under both reverse and normal gravity. The study also proves that the conditions for hysteresis degeneracy under reverse gravity are independent of the excitation frequency.
Article
Mechanics
A. Krikunova, K. Y. Arefyev, A. S. Saveliev, G. A. Kossov, A. D. Cheshko
Summary: Experimental investigation of an inverted conical plane-symmetrical premixed methane-air flame under acoustic excitation explored transitions between different flame front configurations and the effects of acoustic disturbances. New data was obtained, revealing characteristics of hysteresis effects and their influencing factors.
Proceedings Paper
Physics, Condensed Matter
K. Yu Arefyev, A. I. Krikunova, V. A. Panov
XXXIII INTERNATIONAL CONFERENCE ON EQUATIONS OF STATE FOR MATTER
(2019)
Proceedings Paper
Physics, Applied
A. I. Krikunova, A. S. Saveliev, E. E. Son
XXXII INTERNATIONAL CONFERENCE ON INTERACTION OF INTENSE ENERGY FLUXES WITH MATTER (ELBRUS 2017)
(2018)
Proceedings Paper
Physics, Multidisciplinary
A. I. Krikunova, E. E. Son, A. S. Saveliev
XXXI INTERNATIONAL CONFERENCE ON EQUATIONS OF STATE FOR MATTER (ELBRUS 2016)
(2016)