Article
Mechanics
Maximilian Hartmann, Mathis Fricke, Lukas Weimar, Dirk Gruending, Tomislav Maric, Dieter Bothe, Steffen Hardt
Summary: The breakup dynamics of a capillary bridge on a hydrophobic stripe between two hydrophilic stripes is studied using experimental and numerical methods. The breakup process is evaluated in a phase space representation to reduce uncertainty in determining precise breakup time. The study finds that the breakup of the capillary bridge cannot be characterized by a unique scaling relationship, and different scaling exponents apply at different stages of the breakup process.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2021)
Article
Multidisciplinary Sciences
Diana Broboana, Ana-Maria Bratu, Istvan Magos, Claudiu Patrascu, Corneliu Balan
Summary: The dripping regime near fluid droplet breakup has been analyzed through experiments and numerical correlations. The distribution of the zeta-coefficient was found to be a relevant parameter in analyzing and quantifying the breakup process. This study has the potential to develop new techniques and more precise procedures for determining the interfacial rheology of viscous and complex fluids.
SCIENTIFIC REPORTS
(2022)
Article
Mechanics
A. Rubio, E. J. Vega, A. M. Ganan-Calvo, J. M. Montanero
Summary: We experimentally studied the stability of micrometer weakly viscoelastic jets produced with transonic flow focusing. We found that highly stable jets are formed when adding low molecular weight polymer to water at low concentration and reducing the injected flow rate. The capillary instability is delayed and jet breakup occurs at distant locations from the ejected. The intense converging extensional flow in the ejection point results in long-lasting viscoelastic stress that is not relaxed in the jet even for times longer than the polymer relaxation time. The drag force exerted by the outer gas stream and partial polymer entanglement at the jet emission point may contribute to this effect.
Article
Mechanics
Rina Nakajima, Kosuke Hayashi
Summary: Experiments were conducted to study the behavior of liquid drops falling through a miscible liquid. It was observed that the drops deform into vortex rings and fragment into smaller drops due to the Rayleigh-Taylor instability. The number of smaller drops was measured for different Archimedes numbers, and the influence of vortex ring interactions on fragmentation was analyzed.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2022)
Article
Thermodynamics
Fabian Denner, Fabien Evrard, Alfonso Arturo Castrejon-Pita, Jose Rafael Castrejon-Pita, Berend van Wachem
Summary: This study analyses the capillary breakup of a liquid jet under large excitation amplitudes relevant to inkjet printing using numerical simulations. The results show the reversal of breakup length and inversion of breakup modes, both related to the formation of vortex rings and local flow obstruction inside the jet. An empirical similarity model for the breakup length reversal is proposed, allowing accurate prediction of jet behavior in practical situations, especially continuous inkjet printing.
FLOW TURBULENCE AND COMBUSTION
(2022)
Article
Mechanics
Seungho Kim, Anuj Baskota, Hosung Kang, Sunghwan Jung
Summary: Water stuck in the ear is a common issue during water activities, and it can lead to infections and hearing loss. Shaking the head is a common way to remove water from the ear canal. This study investigates the mechanism of water ejection using experiments and a stability theory.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Engineering, Chemical
Hannes Raddant, Georg Broesigke, Christian Hoffmann, Markus Illner, Jens -Uwe Repke
Summary: Extensive research has been conducted to understand the fluid dynamics of liquid film flow in structured packings, focusing mainly on gravity-stabilized flow. However, gravity-destabilized flow, which occurs in about half of the cases in column with structured packings, has been studied less frequently. This study investigates the fundamental fluid dynamics of gravity-destabilized liquid film flows on different surfaces and compares the experimental results with numerical results from literature.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2023)
Article
Mechanics
Runze Duan, Ziwei Feng, Xiaolei Zhang, Qingfei Fu, Hua Yang, Jin Wang, Liansheng Liu
Summary: This paper investigates the phenomenon of droplet formation and methods to eliminate satellite droplets. A drainage device was added to a dropper to suppress the formation of satellite droplets, and the effects of liquid physical parameters and drainage devices on the fracture length of the neckline and the main-droplet diameter were investigated. The impact of the drainage device on the transition of fluid behavior from dripping mode to jetting mode was also studied. The results show that adding a drainage device significantly reduces the fracture length of the neckline, the main-droplet diameter, and the number of satellite droplets.
Article
Crystallography
Alfonso M. Ganan-Calvo, Henry N. Chapman, Michael Heymann, Max O. Wiedorn, Juraj Knoska, Braulio Ganan-Riesco, Jose M. Lopez-Herrera, Francisco Cruz-Mazo, Miguel A. Herrada, Jose M. Montanero, Sasa Bajt
Summary: The successful introduction of samples in Serial Femtosecond Crystallography has been achieved by using microscopic capillary liquid jets produced by gas flow focusing. A classical scaling law with two universal constants has been validated to accurately calculate the length of the liquid jets based on experimental and numerical measurements. The actual length of the jet is determined by nonlinear perturbations from the jet breakup itself, in contrast to the classical conception of temporal stability attributing natural breakup length to jet birth conditions or small interactions with the environment.
Article
Mechanics
Joseph Connell, Murray Rudman, Ranganathan Prabhakar
Summary: The volume and aspect ratio of liquid bridges significantly affect their dynamics and can have adverse effects on rheological characterization. This study uses numerical simulations to investigate the role of these parameters in Newtonian and viscoelastic liquid bridges, and discusses the optimal parameter values to avoid drop formation and slowdown.
Article
Mechanics
Dege Li, Yi Cao, Bingfang Huang, Xinlei Wu, Guofang Hu, Xiaolong Wang, Yonghong Liu, Yanzhen Zhang
Summary: The breakup process of an inviscid liquid bridge sandwiched between two coaxial rods is investigated, with a focus on its profile close to rupture and its influence on subsequent breakup behaviors. The profile of the liquid bridge undergoes a transition from symmetry to asymmetry as the distance between the rods increases. A critical slenderness is found above which the liquid bridge becomes asymmetric and exhibits a well-fitted profile of a sine wave cycle. Experimental and theoretical results show that the ratio of bridge length to equivalent radius is always 2 pi for the asymmetric bridge close to rupture. The influence of slenderness on the time interval between asymmetric pinch-off events, velocity, destination, and size of the satellite droplet is explored.
Article
Chemistry, Physical
P. Dolganov, A. S. Zverev, K. D. Baklanova, V. K. Dolganov
Summary: The investigation revealed two different coalescence regimes when nematic and isotropic droplets coalesce, forming nematic and isotropic bridges in the circular meniscus and only isotropic bridges, respectively. The coalescence of nematic droplets starts near the cell surfaces, while isotropic droplets start coalescing in the middle of the cell. The breakup of the outer bridge during coalescence is a new example of Rayleigh-Plateau instability.
Article
Mechanics
M. Rubio, A. Ponce-Torres, M. A. Herrada, A. M. Ganan-Calvo, J. M. Montanero
Summary: This study investigates experimentally and numerically the thinning process of Newtonian leaky-dielectric filaments under an axial electric field, as well as the influence of the electric field on the formation of satellite droplets. The electric force delays surface pinching, with polarization stress being identified as a key factor in this delay. Additionally, near the pinching point, hydrodynamic forces dominate filament thinning while the polarization stress becomes subdominant despite its divergence at the finite-time singularity.
Article
Computer Science, Interdisciplinary Applications
Mohsen H. Moghimi, Nathan J. Quinlan
Summary: An axisymmetric model has been developed in the finite volume particle method (FVPM) to study the behaviors of liquid droplets, capillary dripping, and jet disintegration. The simulations show good agreement with experimental and theoretical results, validating the accuracy of the model.
COMPUTERS & FLUIDS
(2022)
Article
Mechanics
Darsh K. Nathawani, Matthew G. Knepley
Summary: Droplet formation occurs in a finite amount of time due to surface tension force. Linear stability analysis is useful in estimating the droplet size but fails to approximate its shape. A one-dimensional axisymmetric mathematical model developed through asymptotic analysis provides a universal scaling that explains the self-similar nature of the droplet formation solution.
Article
Engineering, Mechanical
Rosaria Del Toro, Maria Laura De Bellis, Marcello Vasta, Andrea Bacigalupo
Summary: This article presents a multifield asymptotic homogenization scheme for analyzing Bloch wave propagation in non-standard thermoelastic periodic materials. The proposed method derives microscale field equations, solves recursive differential problems within the unit cell, establishes a down-scaling relation, and obtains average field equations. The effectiveness of this approach is validated by comparing dispersion curves with those from the Floquet-Bloch theory.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
Article
Engineering, Mechanical
Yue Bao, Zhengcheng Yao, Yue Zhang, Xueman Hu, Xiandong Liu, Yingchun Shan, Tian He
Summary: This paper proposes a novel triple-gradient phononic acoustic black hole (ABH) beam that strategically manipulates multiple gradients to enhance its performance. The study reveals that the ABH effect is not solely brought about by the thickness gradient, but also extends to the power-law gradients in density and modulus. The synergistic development of three different gradient effects leads to more pronounced and broader bandgaps in PCs.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
Article
Engineering, Mechanical
Matthias Ryser, Jason Steffen, Bekim Berisha, Markus Bambach
Summary: This study investigates the feasibility of replacing complex experiments with multiple simpler ones to determine the anisotropic yielding behavior of sheet metal. The results show that parameter identifiability and accuracy can be achieved by combining multiple specimen geometries and orientations, enhancing the understanding of the yield behavior.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
Article
Engineering, Mechanical
Wenjun Li, Pengfei Zhang, Siyong Yang, Shenling Cai, Kai Feng
Summary: This study presents a novel two-dimensional non-contact platform based on Near-field Acoustic Levitation (NFAL), which can realize both one-dimensional and two-dimensional transportation. Numerical and experimental results prove the feasibility and ease of this method.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
Article
Engineering, Mechanical
Shuo Liu, Lu Che, Guodong Fang, Jun Liang
Summary: This study presents a novel lamina conjugated bond-based peridynamic (BB-PD) model that overcomes the limitations of material properties and is applicable to composite laminates with different stacking sequences. The accuracy and applicability of the model are validated through simulations of elastic deformation and progressive damage behavior, providing an explanation of the damage modes and failure mechanisms of laminated composite materials subjected to uniaxial loading.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
Article
Engineering, Mechanical
Omar El-Khatib, S. Kumar, Wesley J. Cantwell, Andreas Schiffer
Summary: Sandwich-structured honeycombs (SSHCs) are hierarchical structures with enhanced mass-specific properties. A model capable of predicting the elastic properties of hexagonal SSHCs is presented, showing superior in-plane elastic and shear moduli compared to traditional honeycombs, while the out-of-plane shear moduli are reduced.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
Article
Engineering, Mechanical
Zhi-Jian Li, Hong-Liang Dai, Yuan Yao, Jing-Ling Liu
Summary: This paper proposes a process-performance prediction model for estimating the yield strength and ultimate tensile strength of metallic parts fabricated by powder bed fusion additive manufacturing. The effect of main process variables on the mechanical performance of printed metallic parts is analyzed and the results can serve as a guideline for improvement. The accuracy of the proposed model is validated by comparison with literature.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
Article
Engineering, Mechanical
Saman A. Bapir, Kawa M. A. Manmi, Rostam K. Saeed, Abdolrahman Dadvand
Summary: This study numerically investigates the behavior of an ultrasonically driven gas bubble between two parallel rigid circular walls with a cylindrical micro-indentation in one wall. The primary objective is to determine the conditions that facilitate the removal of particulate contamination from the indentation using the bubble jet. The study found that the bubble jet can effectively remove contamination from the indentation for certain ranges of indentation diameter, but becomes less effective for larger indentation diameters.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
Article
Engineering, Mechanical
E. Polyzos, E. Vereroudakis, S. Malefaki, D. Vlassopoulos, D. Van Hemelrijck, L. Pyl
Summary: This research investigates the elastic and damage characteristics of individual composite beads used in 3D printed composites. A new analytical probabilistic progressive damage model (PPDM) is introduced to capture the elastic and damage attributes of these beads. Experimental results show strong agreement with the model in terms of elastic behavior and ultimate strength and strain.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
