Article
Engineering, Aerospace
Ziwan Li, Yixiang Yuan, V. L. Varsegov, Baoting Guo, Bo Xiao, P. H. Duan
Summary: This paper studies the mixing characteristics of circular transverse gas fuel jet in crossflow, showing that a well-mixed mixture is formed in the recirculation zone with high combustion efficiency.
AEROSPACE SCIENCE AND TECHNOLOGY
(2021)
Article
Thermodynamics
Ziwan Li, Yixiang Yuan, Jun Yao, V. L. Varsegov, P. H. Duan, Lu Zhao
Summary: This paper investigates a new method of using circular transverse jet to improve combustion efficiency at off-design conditions. Results show that this method can effectively mix fuel and mainstream airflow, leading to combustion efficiency reaching over 99% under specific conditions. The study of flow field structure and temperature distribution in the combustion zone lays the foundation for further research and engineering application.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2021)
Article
Engineering, Marine
Songchen Yu, Hongde Qin, Peng Li, Fangyu Gong
Summary: This paper aims to understand the hydrodynamic characteristics of the biological fouling net in the open ocean, which is closely related to the safety of the offshore net cage and the survival environment of cultured fish. The equivalent model of the biofouling net is proposed, and the drag force coefficient and flow field variations are studied using large-eddy simulation (LES). The results show that the cross-sections contacted with fluid lead to a smaller drag force coefficient for 2 x 2 cruciform circular cylinder. The influence of net aperture and net twines on the wake is also assessed.
JOURNAL OF MARINE SCIENCE AND TECHNOLOGY
(2023)
Article
Engineering, Environmental
Chun-Kai Gong, Xiao Xu, Qiang Yang
Summary: This study systematically investigated the gas holdup and superficial gas velocity in a lab-scale bubble column. The experimental results showed that a dynamic equilibrium region was achieved at a distance of 2800 mm above the bubble generator. Small initial bubble size led to higher gas holdup and slump trend. By controlling the liquid mass flow in the nozzle, a reasonable gas holdup without slump could be achieved. A semi empirical correlation of gas holdup was established based on previous empirical correlations and experiment data, which provided accurate predictions.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Mechanics
Cai Tian, Zhaoyu Shi, Fengjian Jiang, Helge I. Andersson
Summary: This study simulated the wake of a circular cylinder in mode A at Reynolds number 200 by directly solving the Navier-Stokes equations in three dimensions. It systematically described different topologies of natural vortex dislocations in the mode A wake and identified three new topologies. The formation process and mechanism of these newly identified dislocation topologies were also addressed. The results of this study provide a more thorough understanding of natural vortex dislocations in the mode A wake.
Article
Mechanics
Junyi Mi, Xiaowei Jin, Hui Li
Summary: A network model called Cascade-Net is proposed, which combines machine learning techniques with fluid mechanics to accurately predict the spatiotemporal fluctuating velocity in the near-wall wake of a circular cylinder. The model utilizes a comprehensive dataset obtained through wind tunnel testing and applies convolutional neural networks to predict the velocity fluctuations. The results demonstrate that the Cascade-Net shows good generalization performance and accurately predicts fluctuating velocity fields and the second-order moments at various Reynolds numbers.
Article
Physics, Fluids & Plasmas
Joanne Steiner, Cyprien Morize, Ivan Delbende, Alban Sauret, Philippe Gondret
Summary: In this article, the time evolution of vortex rings generated by the translation of a rigid disk in a fluid is investigated. The startup vortex ring and its dynamics are characterized experimentally and numerically. The observed scaling laws of the maximum radius and circulation of the vortex ring are captured by a modified theoretical model.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Mechanics
Bo Yang, Mehdi Jafarian, Navid Freidoonimehr, Maziar Arjomandi
Summary: This study experimentally investigates the rising trajectory of a spherical microbubble with a diameter of 0.3-1.0mm in a vertical channel with fully developed laminar flow. The lift and drag forces on the bubble are assessed, and a new correlation for lift force coefficient is developed. The study concludes that the lift coefficient for a spherical microbubble in vertical channels with fully developed laminar flow is slightly higher than the reported shear lift coefficient for larger bubbles rising in a high viscous liquid.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2022)
Article
Engineering, Aerospace
Ziwan Li, Yixiang Yuan, V. L. Varsegov, Huazhang Yu, Wenzhe Li, P. H. Duan, Wisam Yousef
Summary: Experimental studies have been conducted on circular transverse methane jets in crossflow, both at stable combustion conditions and approaching flameout. It was observed that a steady recirculation zone forms downstream of the jet under stable combustion, with constant mixing coefficient under different conditions. The combustion temperature and efficiency remain relatively unchanged, especially in the back half of the recirculation zone. However, as the flame approaches to extinguished, the recirculation zone becomes unstable, leading to an increase in the excess air coefficient and a decrease in the combustion temperature. This eventually results in flame oscillation and extinction.
AEROSPACE SCIENCE AND TECHNOLOGY
(2023)
Article
Nuclear Science & Technology
Guangzhan Xu, Zhongning Sun, Xiantao Zhang
Summary: The experimental results reveal five types of bubble coalescence in a volumetrically heated packed bed, where bubble growth plays a crucial role in flow pattern transition by enlarging the contact area between bubbles and particles. The proportion of small bubbles significantly increases with decreasing inlet fluid temperature and increasing mass flux.
ANNALS OF NUCLEAR ENERGY
(2021)
Article
Mechanics
Gaurav Chopra, Sanjay Mittal
Summary: The impact of the height and location of a trip on the transition of boundary layer on a cylinder is investigated using large eddy simulations. Two modes of transition are observed, with natural transition resulting in lower drag and a larger delay.
Article
Mechanics
Weilin Chen, Yuzhu Li
Summary: It was previously believed that the afterbody is essential for the vortex-induced vibration (VIV) of a bluff body. However, a recent study disproved this belief by successfully demonstrating VIV without an afterbody. This study further confirmed the possibility of VIV in a triangular prism without an afterbody and investigated the physical mechanisms behind it.
Article
Engineering, Chemical
Mei Mei, Claude Le Men, Karine Loubiere, Gilles Hebrard, Nicolas Dietrich
Summary: This study investigates the dynamics of bubble formation at a cross-junction in a straight milli-channel. The filling and squeezing stages of the bubble formation process are studied, and their frequencies are compared under various conditions. It is observed that the filling and squeezing frequencies are mainly controlled by the gas and liquid superficial velocities, respectively. The bubble formation frequencies are related to the gas-liquid superficial velocity ratios, liquid superficial velocities, and bubble length. The study also identifies two patterns of bubble formation depending on whether the pinch-off occurs inside the cross-junction or not.
CHEMICAL ENGINEERING SCIENCE
(2022)
Review
Engineering, Chemical
Yanling Chen, Liang Wang, Haijun Chang, Qunwei Zhang
Summary: Although significant efforts have been made in modeling the drag force in gas-liquid two-phase flow, the research in terms of both theory and method is still in the development stage due to the diversity and complexity of the topic. This review paper provides a unified framework for the drag coefficient model in gas-liquid two-phase flow. It explores the drag coefficient of solid particles, single bubbles, bubble swarms, and bubbles in turbulence moving in liquid, discussing the variables that affect the drag coefficient in each situation and the relationship between the drag coefficient and these variables.
CHEMBIOENG REVIEWS
(2023)
Article
Engineering, Environmental
H. Lee, F. Coulon, D. J. Beriro, S. T. Wagland
Summary: The recovery of 12 critical raw materials (CRM) from municipal solid wastes (MSW) via leachate recirculation was evaluated using a 4 L semi-pilot scale column percolation. The results showed that the recovery of the metal (loid)s was mainly influenced by pH, organic content, type of metal(loid)s, age of the waste, and redox potential. A comparison of leachate from the leachate recirculated columns before and after the initiation of recirculation indicates an increase in the concentrations of certain CRM and metalloids. The first recirculation cycle supported achieving 100 % recovery. CRM and metalloids in leachate can be recovered, with concentrations usually below 1 mg/L. Leachate recirculation can enhance the increasing concentration of CRM in landfill leachate.
Article
Engineering, Marine
Hong Xiong, Jianmin Yang, Xinliang Tian
SHIPS AND OFFSHORE STRUCTURES
(2020)
Article
Engineering, Multidisciplinary
Peng Wang, Xinliang Tian, Wenyue Lu, Zhihuan Hu, Yong Luo
APPLIED MATHEMATICAL MODELLING
(2019)
Article
Green & Sustainable Science & Technology
Binrong Wen, Xinliang Tian, Xingjian Dong, Zhanwei Li, Zhike Peng, Wenming Zhang, Kexiang Wei
Article
Physics, Multidisciplinary
Song Gao, Song Pan, Huaicheng Wang, Xinliang Tian
PHYSICAL REVIEW LETTERS
(2020)
Article
Mechanics
Yakun Zhao, Song Gao, Xiantao Zhang, Xiaoxian Guo, Xin Li, Xinliang Tian
Summary: Direct numerical simulations were conducted to investigate the flow around an inclined thin square plate with different conditions, revealing the presence of four flow regimes: steady state, periodic state, quasi-periodic state, and chaotic state. The flow under the IL condition tends to lose symmetry more easily compared to the IS condition, and the critical Reynolds numbers at different bifurcations are generally higher for the square plate than for the circular disk.
Article
Engineering, Ocean
Xiaoxian Guo, Xiantao Zhang, Xinliang Tian, Xin Li, Wenyue Lu
Summary: The study developed an LSTM-based machine learning model to accurately predict motions of semi-submersibles, achieving close to 90% accuracy in predicting future motions up to 46.5 seconds. The trained model effectively worked with high noise levels and was able to predict vessel motions based solely on the motion itself.
APPLIED OCEAN RESEARCH
(2021)
Article
Engineering, Marine
Xin Liang, Peng Wang, Xiantao Zhang, Binrong Wen, Xin Li, Xinliang Tian
Summary: This paper proposes an optimization-based energy management strategy for efficient energy utilization in an environment-powered unmanned surface vehicle (EPUSV). The optimal scheduling for each device is achieved by controlling and coordinating the electric devices. The model is robust to uncertainty parameters and adaptable to different types of tasks.
Article
Mechanics
Danxue Ouyang, Xinliang Tian, Yakun Zhao, Binrong Wen, Xin Li, Jun Li, Tao Peng, Zhike Peng
Summary: Direct numerical simulations are used to investigate wake transitions in flow normal to a rotating disk. Six flow regimes are identified, including symmetrical, steady rotation, unsteady rotation, vortex shedding, and chaotic states. The rotational motion of the disk affects the wake patterns and can suppress vortex shedding.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Engineering, Marine
Peng Wang, Ranran Liu, Xinliang Tian, Xiantao Zhang, Lei Qiao, Yuntao Wang
Summary: This paper proposes a novel speed adaptive robust obstacle avoidance (SAROA) approach for environmentally-driven unmanned surface vehicles (USVs) in large-scale and uncertain environments using deep reinforcement learning (DRL). The approach significantly improves sampling efficiency and convergence through a feature enhanced dynamic training method. The paper also introduces obstacle perception and line-of-sight based target tracking methods to enable collision avoidance and path following in large-scale environments. Additionally, a speed adaptive zone is proposed to enhance the adaptability and robustness of the obstacle avoidance strategy.
Article
Mechanics
Huanyu Zhang, Yakun Zhao, Xinliang Tian, Xiaolong Wang, Hao Liu
Summary: This paper investigates the motion modes transition and dynamic performance of a rigid-flexible coupling system in the flow at low Reynolds numbers. The system consists of a rigid plate and a trailing closed flexible filament, and numerical simulations using the immersed boundary method are conducted. Six motion modes are identified based on the movement of the filament and its symmetry. Drag reduction is observed at Re >= 40, mainly influenced by the pressure behind the filament. However, the drag reduction is weakened for filaments with Lr >= 2.57 due to the increased flow disturbance caused by their large width.
Article
Instruments & Instrumentation
X. Chen, S. Sun, X. Tian, L. Liu, J. Yang
Summary: The use of a tank-in-tank configuration allowed the maintenance of high uniformity in a tall narrow-channel fluid tank by balancing the hydrostatic pressure acting on the channel. Motion characteristics of falling circular disks in the quasi-2D channel were experimentally investigated, revealing four distinct falling types and visualizing the wake flow fields of the disks. An analytical model was established to predict the falling velocity and Reynolds number, and potential future research directions and improvements to the apparatus were suggested.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Review
Engineering, Marine
Xukai Fang, Xiaoxian Guo, Xinliang Tian, Peng Wang, Wenyue Lu, Xin Li
Summary: Floatover is a large deck installation method that transfers the integrated deck from the floatover vessel to the pre-installed substructure. It has advantages of high efficiency, economy, and large lifting capacity, and has been widely used in both fixed and floating platforms. Accurate numerical or experimental models are essential for investigating the dynamic responses and load effects in floatover installations.
Article
Engineering, Marine
Mingsheng Chen, Mingjun Ouyang, Tingqiu Li, Meiyan Zou, Jun Ye, Xinliang Tian
Summary: In multi-body systems, the catamaran float-over installation experiences gap resonance phenomenon due to strong hydrodynamic interactions. By applying the damping lid method, the resonance issue can be effectively resolved. Based on the corrected frequency-domain results, a time-domain model considering various mechanical coupling components was established, and simulations were conducted to investigate the coupling mechanism during different contact stages.
Article
Engineering, Marine
Wenhao Xu, Jianmin Yang, Handi Wei, Haining Lu, Xinliang Tian, Xin Li
Summary: This study proposes a localization algorithm that provides accurate and real-time localization results for deep-sea mining vehicles. It uses forward-looking sonar and image matching to estimate the vehicle's motion and generate 3D point clouds of object features for constructing the odometer. The data fusion algorithm integrates global and relative measurements from multiple sensors using a pose graph framework. Validation results show the algorithm can output accurate positioning results for deep-sea mining vehicles.
Article
Engineering, Marine
Xing Chen, Binrong Wen, Xinliang Tian, Shuyue Sun, Peng Wang, Xin Li
Summary: This study presents a kinematic and hydrodynamic model for a wire-driven robotic fishtail, incorporating experimental investigation. The wire-driven mechanism featuring a continuously compliant backbone and position-variable vertebrae enables more flexible fishtail flapping and adjustable fish morphology. The proposed models have been validated through physical tests in an open-water environment, and exhibit superior response predictive ability compared to traditional methods.
Article
Engineering, Mechanical
Xuyi Jia, Chunlin Gong, Wen Ji, Chunna Li
Summary: A flow sensing method for real-time forecast of flow field in FSI systems using structural deformation is proposed in this study. The method utilizes multilayer POD to improve accuracy and deep neural network to map mode coefficients. The results show that the proposed method performs accurately in flow properties forecasting and is suitable for FSI systems with complex flow structures.
JOURNAL OF FLUIDS AND STRUCTURES
(2024)
Article
Engineering, Mechanical
Paulo H. N. Silva, Gustavo R. S. Assi
Summary: This paper presents an experimental study of fluid-structure interaction, demonstrating that the controlled rotation of rods can reduce mean drag and fluctuating lift forces simultaneously. By using a multi-objective genetic algorithm, the optimum rotation speeds were found, resulting in a more significant reduction in objectives and energy consumption. The contribution of each rod depends on its angular position and the flow conditions generated by the upstream control rods. The study clarifies the physical principles of the phenomenon and paves the way for technological applications.
JOURNAL OF FLUIDS AND STRUCTURES
(2024)
Article
Engineering, Mechanical
Yacine Manal, Pascal Hemon
Summary: Synchronized unsteady wall pressure measurements were performed on a full-scale circular chimney subjected to natural wind. The analysis of the pressure distribution using bi-orthogonal decomposition was crucial for the success of the processing. The results showed that atmospheric turbulence plays a significant role in the unsteady pressure response on the chimney, generating high levels of RMS pressure.
JOURNAL OF FLUIDS AND STRUCTURES
(2024)
Article
Engineering, Mechanical
Hironori Takeda, Yusuke Asai, Shunichi Ishida, Yasutoshi Taniguchi, Takuya Terahara, Kenji Takizawa, Yohsuke Imai
Summary: Wrinkling and creasing of an elastic membrane in a shear flow can be influenced by shear rate and membrane thickness. The deformation type can be determined by mechanical and geometrical effects of the membrane thickness, based on the geometrical consistency of the capsule surface.
JOURNAL OF FLUIDS AND STRUCTURES
(2024)
