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Journal articles on the topic 'Kirchhoff vortex'

Author: Grafiati

Published: 9 November 2024

Last updated: 31 July 2025

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1

Wan, Yieh-Hei. "Bifurcation At Kirchhoff Elliptic vortex with eccentricity." Dynamics and Stability of Systems 13, no. 3 (1998): 281–97. http://dx.doi.org/10.1080/02681119808806265.

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2

STRAWN, ROGER C., RUPAK BISWAS, and ANASTASIOS S. LYRINTZIS. "HELICOPTER NOISE PREDICTIONS USING KIRCHHOFF METHODS." Journal of Computational Acoustics 04, no. 03 (1996): 321–39. http://dx.doi.org/10.1142/s0218396x96000106.

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This paper presents two methods for predicting the noise from helicopter rotors in forward flight. Aerodynamic and acoustic solutions in the near field are computed with a finite-difference solver for the Euler equations. Two different Kirchhoff acoustics methods are then used to propagate the acoustic signals to the far field in a computationally-efficient manner. One of the methods uses a Kirchhoff surface that rotates with the rotor blades. The other uses a nonrotating Kirchhoff surface. Results from both methods are compared to experimental data for both high-speed impulsive noise and blad

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3

OVCHINNIKOV, Y. N., and I. M. SIGAL. "The energy of Ginzburg–Landau vortices." European Journal of Applied Mathematics 13, no. 2 (2002): 153–78. http://dx.doi.org/10.1017/s0956792501004752.

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We consider the Ginzburg–Landau equation in dimension two. We introduce a key notion of the vortex (interaction) energy. It is defined by minimizing the renormalized Ginzburg–Landau (free) energy functional over functions with a given set of zeros of given local indices. We find the asymptotic behaviour of the vortex energy as the inter-vortex distances grow. The leading term of the asymptotic expansion is the vortex self-energy while the next term is the classical Kirchhoff–Onsager Hamiltonian. To derive this expansion we use several novel techniques.

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4

Vladimirov, V. A., and K. I. Il'in. "Three-dimensional instability of an elliptic Kirchhoff vortex." Fluid Dynamics 23, no. 3 (1988): 356–60. http://dx.doi.org/10.1007/bf01054740.

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5

Crowdy, Darren, and Jonathan Marshall. "Analytical formulae for the Kirchhoff–Routh path function in multiply connected domains." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 461, no. 2060 (2005): 2477–501. http://dx.doi.org/10.1098/rspa.2005.1492.

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Explicit formulae for the Kirchhoff–Routh path functions (or Hamiltonians) governing the motion of N -point vortices in multiply connected domains are derived when all circulations around the holes in the domain are zero. The method uses the Schottky–Klein prime function to find representations of the hydrodynamic Green's function in multiply connected circular domains. The Green's function is then used to construct the associated Kirchhoff–Routh path function. The path function in more general multiply connected domains then follows from a transformation property of the path function under co

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6

Liang, Bin, Roger M. Waxler, and Paul Markowski. "A theory for the emission of infrasound from Tornadoes." Journal of the Acoustical Society of America 155, no. 3_Supplement (2024): A202. http://dx.doi.org/10.1121/10.0027306.

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Tornadoes have been shown to radiate infrasound to great distances, however convincing fundamental sound mechanisms are still absent. After using vortex sound theory to study sound generated by two numerical tornadoes, we found that there is a significant low-frequency signal between 0.1 Hz and 1 Hz. The sound is closely related to rotation of the non-axisymmetric vorticity field and its frequency depends on the rotational frequency. The non-axisymmetric vorticity field is represented by a Kirchhoff vortex-like flow in baseline tornado model and by multiple-vortex flow in eddy injection tornad

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7

Hong, Shuli, Jun Chi, Xin Xiang, and Weiyu Lu. "Theoretical Model and Numerical Analysis of the Tip Leakage Vortex Variations of a Centrifugal Compressor." Aerospace 9, no. 12 (2022): 830. http://dx.doi.org/10.3390/aerospace9120830.

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A centrifugal compressor of a micro turbine generator system is investigated by the theoretical model and numerical analysis to explore the characteristics of the tip leakage vortex as the centrifugal compressor approaches stall. The numerical simulation results show the cross-sectional shape of the tip leakage vortex is elliptical, and its long and short axes are gradually stretched as the compressor approaches stall. Moreover, the vortex trajectory is inclined to the pressure side of the adjacent blade. In addition, the Kirchhoff elliptical vortex model is introduced to analyze the flow pass

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8

Nagem, Raymond, Guido Sandri, David Uminsky, and C. Eugene Wayne. "Generalized Helmholtz–Kirchhoff Model for Two-Dimensional Distributed Vortex Motion." SIAM Journal on Applied Dynamical Systems 8, no. 1 (2009): 160–79. http://dx.doi.org/10.1137/080715056.

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9

Zhang, Xiaoxiao, Xiang Su, Zhensen Wu, and Shanzhe Wang. "Analyzing Vortex Light Beam Scattering Characteristics from a Random Rough Surface." Photonics 10, no. 9 (2023): 955. http://dx.doi.org/10.3390/photonics10090955.

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The propagation and scattering of vortex light beams in complex media have significant implications in the fields of laser imaging, optical manipulation, and communication. This paper investigates the scattering characteristics of vortex light beams from a random rough surface. Firstly, a two-dimensional Gaussian rough surface is generated using the Monte Carlo method combined with the linear filtering method. Subsequently, the vortex beams are decomposed into the superposition of infinite plane waves, and the scattering of each plane wave from the rough surface is calculated using the Kirchho

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10

Fukumoto, Yasuhide. "Analogy between a vortex-jet filament and the Kirchhoff elastic rod." Fluid Dynamics Research 39, no. 7 (2007): 511–20. http://dx.doi.org/10.1016/j.fluiddyn.2006.12.004.

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11

Pérez-Chavela, Ernesto, and Sławomir Rybicki. "Topological bifurcation of relative equilibria for the Kirchhoff 8-vortex problem." Journal of Mathematical Analysis and Applications 427, no. 1 (2015): 1–16. http://dx.doi.org/10.1016/j.jmaa.2015.02.022.

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12

Müller, Bernhard, and H. C. Yee. "High order numerical simulation of sound generated by the Kirchhoff vortex." Computing and Visualization in Science 4, no. 3 (2002): 197–204. http://dx.doi.org/10.1007/s007910100072.

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13

Soifer, Viktor, Sergey Kharitonov, Svetlana Khonina, Yurii Strelkov, and Alexey Porfirev. "Spiral Caustics of Vortex Beams." Photonics 8, no. 1 (2021): 24. http://dx.doi.org/10.3390/photonics8010024.

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We discuss the nonparaxial focusing of laser light into a three-dimensional (3D) spiral distribution. For calculating the tangential and normal components of the electromagnetic field on a preset curved surface we propose an asymptotic method, using which we derive equations for calculating stationary points and asymptotic relations for the electromagnetic field components in the form of one-dimensional (1D) integrals over a radial component. The results obtained through the asymptotic approach and the direct calculation of the Kirchhoff integral are identical. For a particular case of focusin

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14

CROWDY, DARREN G. "Exact solutions for rotating vortex arrays with finite-area cores." Journal of Fluid Mechanics 469 (October 15, 2002): 209–35. http://dx.doi.org/10.1017/s0022112002001817.

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A class of explicit solutions of the two-dimensional Euler equations consisting of a finite-area patch of uniform vorticity surrounded by a finite distribution of co- rotating satellite line vortices is constructed. The results generalize the classic study of co-rotating vortex arrays by J. J. Thomson. For N satellite line vortices (N [ges ] 3) a continuous one-parameter family of rotating vortical equilibria is derived in which different values of the continuous parameter correspond to different shapes and areas of the central patch. In an appropriate limit, vortex patch equilibria with cuspe

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15

Liang, Bin, Roger M. Waxler, and Paul Markowski. "A lower frequency signal emitted from tornadoes based on a new mechanism." Journal of the Acoustical Society of America 153, no. 3_supplement (2023): A283. http://dx.doi.org/10.1121/10.0018854.

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Tornadoes have been shown to radiate infrasound to great distances. After using Lighthill's acoustical analogy to study sound generated by a numerical tornado, we found that there is a significant low-frequency signal between 0.1 Hz and 0.5 Hz. We hypothesized that there is a Kirchhoff vortex-like source at the center of the numerical tornado. Based on vortex sound theory, characteristic frequencies only depend on the strength of the vertical vorticity which can change at different heights of the tornado. Compared to real data analysis, there is a possibility that when a tornado occurs, infras

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16

dos Santos, Carlos R., and Flávio D. Marques. "Lift Prediction Including Stall, Using Vortex Lattice Method with Kirchhoff-Based Correction." Journal of Aircraft 55, no. 2 (2018): 887–91. http://dx.doi.org/10.2514/1.c034451.

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17

Xue, Yu, and A. S. Lyrintzis. "Rotating Kirchhoff method for three-dimensional transonic blade-vortex interaction hover noise." AIAA Journal 32, no. 7 (1994): 1350–59. http://dx.doi.org/10.2514/3.12202.

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18

Peterson, Sean D., and Maurizio Porfiri. "Interaction of a vortex pair with a flexible plate in an ideal quiescent fluid." Journal of Intelligent Material Systems and Structures 23, no. 13 (2012): 1485–504. http://dx.doi.org/10.1177/1045389x11435995.

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The coupled interaction of a cantilevered Kirchhoff–Love plate with two vortex filaments of equal and opposite circulation in an infinite incompressible, inviscid, and irrotational fluid domain is investigated. The vortices initially advect toward the cantilevered plate, which is oriented perpendicular to the direction of propagation of the vortex pair and undergoes cylindrical bending. As the pair approaches the plate, the pressure field induced by the vortices deflects the plate and initiates vibration of the structure. The vibration of the structure, in turn, alters the path of the two vort

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19

Konovalyuk, T. P., T. S. Krasnopolskaya, and E. D. Pechuk. "Influence of the internal dynamics of the interacting coherent vortex structures to the generated sound field." Bulletin of Taras Shevchenko National University of Kyiv. Series: Physics and Mathematics, no. 3 (2021): 51–54. http://dx.doi.org/10.17721/1812-5409.2021/3.7.

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The article is dedicated to the glowing memory of the talented Ukrainian scientist-mechanic, professor, doctor of physical and mathematical sciences Vyacheslav Vladimirovich Meleshko. The sound fields of several coherent vortex structures interacting with each other were calculated using the moment model (MZS-model) of the first and second orders. In the first-order MZS-model, vortices are described by point vortices, in the second-order MZS-model--by Kirchhoff vortices. Sound fields as a result of vortex interaction are calculated using the Lighthill's acoustic analogy under Powell's formulat

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20

MITCHELL, BRIAN E., SANJIVA K. LELE, and PARVIZ MOIN. "Direct computation of the sound generated by vortex pairing in an axisymmetric jet." Journal of Fluid Mechanics 383 (March 25, 1999): 113–42. http://dx.doi.org/10.1017/s0022112099003869.

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The sound generated by vortex pairing in axisymmetric jets is determined by direct solution of the compressible Navier–Stokes equations on a computational grid that includes both the near field and a portion of the acoustic far field. At low Mach number, the far-field sound has distinct angles of extinction in the range of 60°–70° from the jet's downstream axis which can be understood by analogy to axisymmetric, compact quadrupoles. As the Mach number is increased, the far-field sound takes on a superdirective character with the dominant sound directed at shallow angles to the jet's downstream

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21

Ewert, R., J. W. Delfs, and M. Lummer. "The Simulation of Airframe Noise Applying Euler-Perturbation and Acoustic Analogy Approaches." International Journal of Aeroacoustics 4, no. 1-2 (2005): 69–91. http://dx.doi.org/10.1260/1475472053729996.

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The capability of three different perturbation approaches to tackle airframe noise problems is studied. The three approaches represent different levels of complexity and are applied to trailing edge noise problems. In the Euler-perturbation approach the linearized Euler equations without sources are used as governing acoustic equations. The sound generation and propagation is studied for several trailing edge shapes (blunt, sharp, and round trailing edges) by injecting upstream of the trailing edge test vortices into the mean-flow field. The efficiency to generate noise is determined for the t

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22

SI, HAI-QING, and TONG-GUANG WANG. "CALCULATION OF THE UNSTEADY AIRLOADS ON WIND TURBINE BLADES UNDER YAWED FLOW." Modern Physics Letters B 23, no. 03 (2009): 493–96. http://dx.doi.org/10.1142/s0217984909018734.

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A dynamic stall model is coupled with the blade element momentum theory to calculate the cyclic variation of the aerodynamic characteristics of the wind turbine in yawed flow. In the dynamic stall model, unsteady effects under attached flow conditions are simulated by the superposition of indicial aerodynamic responses. The movement of the unsteady flow separation point is related to the static separation based on the Kirchhoff flow model via a deficiency function, in which the unsteady boundary layer response and the leading edge pressure response are taken into consideration. The induced vor

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23

Gai, S. L. "Some features of steady separated flow from low speed to hypersonic." Aeronautical Journal 112, no. 1128 (2008): 109–13. http://dx.doi.org/10.1017/s0001924000002049.

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Steady non-vortex shedding base flow behind a bluff body is considered. Such a flow is characterised by the flow separation at the trailing edge of the body with an emerging shear layer which reattaches on the axis with strong recompression and recirculating flow bounded by the base, the shear layer, and the axis. Steady wake flows behind a bluff body at low speeds have been studied for more than a century (for example, Kirchhoff; Riabouchinsky). Recently, research on steady bluff body wake flow at low speeds has been reviewed and reinterpreted by Roshko. Roshko has also commented on some basi

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24

Zang, Huaping, Jingzhe Li, Chenglong Zheng, et al. "The Generation of Equal-Intensity and Multi-Focus Optical Vortices by a Composite Spiral Zone Plate." Photonics 11, no. 5 (2024): 466. http://dx.doi.org/10.3390/photonics11050466.

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We propose a new vortex lens for producing multiple focused coaxial vortices with approximately equal intensities along the optical axis, termed equal-intensity multi-focus composite spiral zone plates (EMCSZPs). In this typical methodology, two concentric conventional spiral zone plates (SZPs) of different focal lengths were composited together and the alternate transparent and opaque zones were arranged with specific m-bonacci sequence. Based on the Fresnel–Kirchhoff diffraction theory, the focusing properties of the EMCSZPs were calculated in detail and the corresponding demonstration exper

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25

Ramos, Juan I. "Finite Difference Methods Based on the Kirchhoff Transformation and Time Linearization for the Numerical Solution of Nonlinear Reaction–Diffusion Equations." Computation 12, no. 11 (2024): 218. http://dx.doi.org/10.3390/computation12110218.

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Four formulations based on the Kirchhoff transformation and time linearization for the numerical study of one-dimensional reaction–diffusion equations, whose heat capacity, thermal inertia and reaction rate are only functions of the temperature, are presented. The formulations result in linear, two-point boundary-value problems for the temperature, energy or heat potential, and may be solved by either discretizing the second-order spatial derivative or piecewise analytical integration. In both cases, linear systems of algebraic equations are obtained. The formulation for the temperature is ext

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26

Candelier, Fabien, Mathieu Porez, and Frederic Boyer. "Note on the swimming of an elongated body in a non-uniform flow." Journal of Fluid Mechanics 716 (January 28, 2013): 616–37. http://dx.doi.org/10.1017/jfm.2012.560.

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AbstractThis paper presents an extension of Lighthill’s large-amplitude elongated-body theory of fish locomotion which enables the effects of an external weakly non-uniform potential flow to be taken into account. To do so, the body is modelled as a Kirchhoff beam, made up of elliptical cross-sections whose size may vary along the body, undergoing prescribed deformations consisting of yaw and pitch bending. The fluid velocity potential is decomposed into two parts corresponding to the unperturbed potential flow, which is assumed to be known, and to the perturbation flow. The Laplace equation a

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27

HAZEL, ANDREW L., and MATTHIAS HEIL. "Three-dimensional airway reopening: the steady propagation of a semi-infinite bubble into a buckled elastic tube." Journal of Fluid Mechanics 478 (March 10, 2003): 47–70. http://dx.doi.org/10.1017/s0022112002003452.

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We consider the steady propagation of an air finger into a buckled elastic tube initially filled with viscous fluid. This study is motivated by the physiological problem of pulmonary airway reopening. The system is modelled using geometrically nonlinear Kirchhoff–Love shell theory coupled to the free-surface Stokes equations. The resulting three-dimensional fluid–structure-interaction problem is solved numerically by a fully coupled finite element method.The system is governed by three dimensionless parameters: (i) the capillary number, Ca=μU/σ*, represents the ratio of viscous to surface-tens

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28

Miyazaki, Takeshi, and Hideshi Hanazaki. "Baroclinic instability of Kirchhoff's elliptic vortex." Journal of Fluid Mechanics 261 (February 25, 1994): 253–71. http://dx.doi.org/10.1017/s0022112094000339.

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The linear instability of Kirchhoff's elliptic vortex in a vertically stratified rotating fluid is investigated using the quasi-geostrophic, f-plane approximation. Any elliptic vortex is shown to be unstable to baroclinic disturbances of azimuthal wavenumber m = 1 (bending mode) and m = 2 (elliptical deformation). The axial wavenumber of the unstable bending mode approaches Λc = 1.7046 in the limit of small ellipticity, indicating that it is a short-wave baroclinic instability. The instability occurs when the bending wave rotates around the vortex axis with angular velocity identical to the ro

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29

Miyazaki, Takeshi, Takeshi Imai, and Yasuhide Fukumoto. "Three‐dimensional instability of Kirchhoff’s elliptic vortex." Physics of Fluids 7, no. 1 (1995): 195–202. http://dx.doi.org/10.1063/1.868719.

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30

Miyazaki, Takeshi, and Hideshi Hanazaki. "Corrigenda: Baroclinic instability of Kirchhoff's elliptic vortex." Journal of Fluid Mechanics 274 (September 10, 1994): 405. http://dx.doi.org/10.1017/s002211209400217x.

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31

Xiong, Jiaming, Song Sang, Youwei Du, Chaojie Gan, Ao Zhang, and Fugang Liu. "Kinematic Stability Analysis of Anchor Cable Structures in Submerged Floating Tunnel under Combined Parametric–Vortex Excitation." Journal of Marine Science and Engineering 12, no. 9 (2024): 1478. http://dx.doi.org/10.3390/jmse12091478.

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The submerged floating tunnel is a marine transportation infrastructure that links two shorelines. The tunnel tube body’s buoyancy exceeds gravity, with anchoring ensuring equilibrium. Anchoring reliability is crucial. This study presents a three-way coupled kinematic model for the mooring structure, formulated on Hamilton’s principle and Kirchhoff’s assumption. It explores the impact of the tube body’s buoyancy-to-weight ratio and the sea current’s angle of incidence on mooring motion response. By solving the motion analysis model, Hill’s equation system is derived to assess the parameter ins

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32

Nath, Anu V. S., and Anubhab Roy. "Clustering and chaotic motion of heavy inertial particles in an isolated non-axisymmetric vortex." Journal of Fluid Mechanics 998 (November 5, 2024). http://dx.doi.org/10.1017/jfm.2024.831.

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We investigate the dynamics of heavy inertial particles in a flow field due to an isolated, non-axisymmetric vortex. For our study, we consider a canonical elliptical vortex – the Kirchhoff vortex and its strained variant, the Kida vortex. Contrary to the anticipated centrifugal dispersion of inertial particles, which is typical in open vortical flows, we observe the clustering of particles around co-rotating attractors near the Kirchhoff vortex due to its non-axisymmetric nature. We analyse the inertia-modified stability characteristics of the fixed points, highlighting how some of the fixed

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33

Miyoshi, Hiroyuki, Darren G. Crowdy, Hiroki Miyazako, and Takaaki Nara. "Equivalent local force conditions minimizing the Frank free energy for topological defect equilibria in nematic liquid crystals." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 481, no. 2308 (2025). https://doi.org/10.1098/rspa.2024.0569.

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Recently, Miyoshi et al . (Miyoshi et al . 2024 Proc. R. Soc. A 480 , 20240405 (doi: 10.1098/rspa.2024.0405 )) derived analytical formulas for the Frank free energy associated with multiple topological defects in nematic liquid crystals confined to an arbitrary simply connected domain. The energy formulas, derived using an analogy with the so-called Kirchhoff–Routh path function in point vortex dynamics, required the evaluation of contour integrals involving analytical formulas associated with the crystal alignment field. Equilibria for topological defects were then obtained by finding local e

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34

Ceci, Stefano, and Christian Seis. "On the dynamics of point vortices for the two-dimensional Euler equation with L ^p vorticity." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 380, no. 2226 (2022). http://dx.doi.org/10.1098/rsta.2021.0046.

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We study the evolution of solutions to the two-dimensional Euler equations whose vorticity is sharply concentrated in the Wasserstein sense around a finite number of points. Under the assumption that the vorticity is merely L p integrable for some p > 2 , we show that the evolving vortex regions remain concentrated around points, and these points are close to solutions to the Helmholtz–Kirchhoff point vortex system. This article is part of the theme issue ‘Mathematical problems in physical fluid dynamics (part 2)’.

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35

McPhail, Michael, and Michael Krane. "Aeroacoustic source prediction using material surfaces bounding the flow." Fluid Dynamics Research, May 9, 2022. http://dx.doi.org/10.1088/1873-7005/ac6e02.

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Abstract This article presents an extension of Liepmann's characterization of an aeroacoustic source in terms of the motion of a bounding surface containing the source region. Rather than using an arbitrary surface, we express the problem in terms of bounding material surfaces, identified by Lagrangian Coherent Structures (LCS), which demarcate flow into regions with distinct dynamics. The sound generation of the flow is written in terms of the motion of these material surfaces using the Kirchhoff integral equation, so that the flow noise problem now appears like that of a deforming body. This

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36

Ahmedou, Mohameden, Thomas Bartsch, and Tim Fiernkranz. "Equilibria of vortex type Hamiltonians on closed surfaces." Topological Methods in Nonlinear Analysis, February 26, 2023, 1–18. http://dx.doi.org/10.12775/tmna.2023.003.

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We prove the existence of critical points of vortex type Hamiltonians \[ H(p_1,\ldots, p_N) = \sum_{{i,j=1}\atop{i\ne j}} ^N \Gamma_i\Gamma_jG(p_i,p_j)+\Psi(p_1,\dots,p_N) \] on a closed Riemannian surface $(\Sigma,g)$ which is not homeomorphic to the sphere or the projective plane. Here $G$ denotes the Green function of the Laplace-Beltrami operator in $\Sigma$, $\Psi\colon \Sigma^N\to\mathbb{R}$ may be any function of class ${\mathcal C}^1$, and $\Gamma_1,\dots,\Gamma_N\in\mathbb{R}\setminus\{0\}$ are the vorticities. The Kirchhoff-Routh Hamiltonian from fluid dynamics corresponds to $\Psi(p

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37

Bagmanov, Valeriy, Liaisan Bakirova, Grigory Voronkov, Vladimir Lyubopytov, Elizaveta Grakhova, and Ruslan Kutluyarov. "Mathematical model of the optical vortex beams emission by the integrated microring resonator with grating." Journal of Optics, March 6, 2025. https://doi.org/10.1088/2040-8986/adbd51.

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Abstract The paper proposes a novel mathematical model of emission and spatial distribution of the optical radiation that carries orbital angular momentum, i.e. optical vortex beams, by microring resonators. The considered microring resonator features a diffraction grating formed by holes perforated on its surface, facilitating the emission of vortex beams. The emission process is analytically examined using the theory of scattering electromagnetic waves by permittivity inhomogeneities, applying the Rayleigh approximation. We use the vector representation of the electromagnetic fields utilizin

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38

Edgar Moafo Wembe, Boris, Olivier Cots, and Bernard Bonnard. "A Zermelo navigation problem with a vortex singularity." ESAIM: Control, Optimisation and Calculus of Variations, August 25, 2020. http://dx.doi.org/10.1051/cocv/2020058.

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Helhmoltz-Kirchhoff equations of motions of vortices of an incompressible fluid in the plane define a dynamics with singularities and this leads to a Zermelo navigation problem describing the ship travel in such a field where the control is the heading angle. Considering one vortex, we define a time minimization problem, geometric frame being the extension of Randers metrics in the punctured plane, with rotational symmetry. Candidates as minimizers are parameterized thanks to the Pontryagin Maximum Principle as extremal solutions of a Hamiltonian vector field. We analyze the time minimal solut

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39

Miyoshi, Hiroyuki, Hiroki Miyazako, and Takaaki Nara. "Free energy formulae for confined nematic liquid crystals based on analogies with Kirchhoff–Routh theory in vortex dynamics." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 480, no. 2300 (2024). http://dx.doi.org/10.1098/rspa.2024.0405.

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Active nematics are influenced by alignment angle singularities called topological defects. The localization of these defects is of major interest for biological applications. The total distortion of alignment angles due to defects is evaluated using Frank free energy, which is one of the criteria used to determine the location and stability of these defects. Previous work used the line integrals of a complex potential associated with the alignments for the energy calculation (Miyazako and Nara 2022 R. Soc. Open Sci . 9 , 211663 (doi: 10.1098/rsos.211663 )), which has a high computational cost

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40

Jeong, Yu Sin, K. Nandakumar Chandran, Tae Woo Kwon, S. Kumar Ranjith, and Man Yeong Ha. "Dynamics of an eccentric identical bubble pair in a quiescent liquid column." Physics of Fluids 37, no. 3 (2025). https://doi.org/10.1063/5.0255708.

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Bubble-induced turbulence and mixing has been identified as a prominent passive approach in enhancing heat and mass transfer associated with engineering applications. This study numerically analyzes buoyancy-driven interactions between initially eccentric bubble pairs in a quiescent liquid column. The effects of fluid parameters and initial eccentricity (ϵ*) on bubble hydrodynamics are examined. Using the volume-of-fluid method with a finite volume approach, the bubble–fluid interface is precisely captured, while the lateral migration of the trailing bubble (TB) relative to the leading bubble

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41

Zang, Huaping, Baozhen Wang, Chenglong Zheng, et al. "Performance analysis of single-focus phase singularity based on elliptical reflective annulus quadrangle-element coded spiral zone plates." Chinese Physics B, June 14, 2023. http://dx.doi.org/10.1088/1674-1056/acde4f.

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Abstract Optical vortices generated by the conventional vortex lens are usually disturbed by the undesired higher order foci which may lead to additional artifacts and thus degrade contrast sensitivity. Herein, in this work, we propose an efficient methodology to combine the merit of elliptical reflective zone plates (ERZPs) and the advantage of spiral zone plates (SZPs) in establishing a specific single optical element, termed elliptical reflective annulus quadrangle-element coded spiral zone plates (ERAQSZPs) to generate single-focus phase singularity. Differing from the abrupt reflectance o

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"Baroclinic instability of Kirchhoff's elliptic vortex." Oceanographic Literature Review 41, no. 9 (1994): 721. https://doi.org/10.1016/0967-0653(94)91870-8.

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"Three-dimensional instability of Kirchhoff's elliptic vortex." Oceanographic Literature Review 42, no. 8 (1995): 629. https://doi.org/10.1016/0967-0653(95)96377-h.

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Elgammi, Moutaz, and Tonio Sant. "A Modified Beddoes–Leishman Model for Unsteady Aerodynamic Blade Load Computations on Wind Turbine Blades." Journal of Solar Energy Engineering 138, no. 5 (2016). http://dx.doi.org/10.1115/1.4034241.

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A modified version of the Beddoes–Leishman (B-L) dynamic stall model is presented. A novel approach was applied for deriving the effective flow separation points using two-dimensional (2D) static wind tunnel test data in conjunction with Kirchhoff's model. The results were then fitted in a least-squares sense using a new nonlinear model that gives a better fit for the effective flow separation point under a wide range of operating conditions with fewer curve fitting coefficients. Another model, based on random noise generation, was also integrated within the B-L model to simulate the effects o

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45

Shashikanth, Banavara N. "Application of Kirchhoff’s equations of motion to the dynamically coupled system of a rigid body with a completely-liquid-filled cavity." Mathematics and Mechanics of Solids, February 17, 2023, 108128652311513. http://dx.doi.org/10.1177/10812865231151391.

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This paper considers the dynamical problem of a rigid body with a cavity that is completely filled by a liquid. The dynamically coupled motion of the rigid body and the liquid is examined in the absence of any external forces or torques. This problem is not new, but the paper draws attention to the fact that Kirchhoff’s equation of motion, which was derived for the dynamically coupled motion of a homogeneous rigid body fully immersed in a liquid, applies to this problem as well. The methodology is explained. Details of a simple, idealized planar example, in which a vorticity field in the form

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