Journal articles: 'Hydrodynamic Forces'

1

Kolkman, P. A. "Hydrodynamic forces." Journal of Fluids and Structures 6, no. 4 (July 1992): 524. http://dx.doi.org/10.1016/0889-9746(92)90030-7.

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Chaudhuri, A. K. "Viscous Hydrodynamic Model for Relativistic Heavy Ion Collisions." Advances in High Energy Physics 2013 (2013): 1–25. http://dx.doi.org/10.1155/2013/693180.

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Viscous hydrodynamical modeling of relativistic heavy ion collisions has been highly successful in explaining bulk of the experimental data in RHIC and LHC energy collisions. We briefly review viscous hydrodynamics modeling of high energy nuclear collisions. Basic ingredients of the modeling, the hydrodynamic equations, relaxation equations for dissipative forces, are discussed. Hydrodynamical modeling being a boundary value problem, we discuss the initial conditions, freeze-out process. We also show representative simulation results in comparison with experimental data. We also discuss the recent developments in event-by-event hydrodynamics.

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3

Ivlev, B. I. "Hydrodynamic fluctuation forces." Journal of Physics: Condensed Matter 14, no. 19 (May 2, 2002): 4829–42. http://dx.doi.org/10.1088/0953-8984/14/19/310.

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4

Isaacson, Michael. "Wave and current forces on fixed offshore structures." Canadian Journal of Civil Engineering 15, no. 6 (December 1, 1988): 937–47. http://dx.doi.org/10.1139/l88-125.

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The Canadian Standards Association standard S471 "General requirements, design criteria, environment, and loads, Part 1 of the CSA code for the design, construction and installation of fixed offshore structures" contains an appendix "Wave and current loads." To compliment this appendix, the present paper provides a more detailed survey of this topic with a review of the recent literature and recommendations of hydrodynamic data needed in offshore design. In addition, hydrodynamic considerations in the calculation of earthquake and ice loads are mentioned. Key words: currents, current forces, hydrodynamics, ocean engineering, offshore structures, waves, wave forces.

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5

Jayaratne, Ravindra, Mara Nicholas, Behnaz Ghodoosipour, Sophie Mugnaini, Ioan Nistor, and Tomoya Shibayama. "TSUNAMI-INDUCED HYDRODYNAMICS AND SCOUR AROUND STRUCTURES." Coastal Engineering Proceedings, no. 36 (December 30, 2018): 5. http://dx.doi.org/10.9753/icce.v36.currents.5.

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The complex hydrodynamics during a tsunami event can significantly affect the structural integrity of buildings. The resulting hydrodynamic forces are influenced by various fluid parameters such as the fluid density, flow velocity and depth, as well as by the structureâ€™s geometry. Hydrodynamic forces induced by tsunami pressures and velocities are particularly important, as they occur usually around a coastal defence structure or a building and as a result, they affect the structural integrity of the structure (Chinnarasri et al, 2013). The 2011 Japan post-tsunami field survey of Chock et al. (2013) indicated that lateral pressures, uplift pressures and surge flow from the tsunami produced hydrodynamic forces responsible for the destruction of many structures along the Tohoku coastline. The associated hydrodynamic parameters of a tsunami such as pressures and velocities also influence the tsunami-induced scour around buildings. Nicholas et al. (2016) stated that the tsunami-induced hydrodynamic velocity was a crucial factor in producing soil-scour around building structures.

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Svoykin, A. O. "Reducing the hydrodynamic force in the hydraulic distributor by modernizing the spool coupe parts." Nauchno-tekhnicheskiy vestnik Bryanskogo gosudarstvennogo universiteta 7, no. 4 (December 25, 2021): 356–68. http://dx.doi.org/10.22281/2413-9920-2021-07-04-356-368.

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Due to a sharp change in the direction and velocity of the fluid flow in the hydraulic distributor, hydrodynamic forces arise. When positioning and holding the spool, the magnitude of the above forces determines the required control power. The aim of the article was to find an optimal constructive solution that would reduce the influence of hydrodynamic forces. In the article we have considered the theoretical foundations laid in the analytical solution of the problem of calculating the magnitude of the hydrodynamic force acting on the plunger of the spool. In addition, a numerical experiment was carried out using CAD Solidworks and the Flow Simulation application package and a comparison of the results obtained with the analytical solution of the problem. During the numerical experiment, it was found that by upgrading the spool sleeve, it is possible to reduce the value of the hydrodynamic force by 4.5 times, compared with the original design. At the same time, it was found that the modernization of the plunger does not further reduce the maximum hydrodynamic forces. The article highlights the economic benefits of reducing the required power to control the hydraulic distributor. The article may be of interest to both researchers whose research interests lie in the field of hydrodynamics, and manufacturers of hydraulics.

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7

Li, Yajie, and Yun Long. "Numerical Study on Wave Radiation by a Barge with Large Amplitudes and Frequencies." Journal of Marine Science and Engineering 8, no. 12 (December 19, 2020): 1034. http://dx.doi.org/10.3390/jmse8121034.

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A two-dimensional boundary element method is used to study the hydrodynamics of a single barge with prescribed motions of large amplitudes and high frequencies. The wave radiation problem is solved in the time domain based on the fully nonlinear potential flow theory. For numerical simulations, special treatments like plunging wave cutting and remeshing approaches are presented in detail. The numerical schemes are verified through comparing with analytical results. Both the generated outgoing wave amplitudes and hydrodynamic coefficients can be calculated with sufficient accuracy. Then, we focus on large heave, sway and roll motions to investigate the nonlinear effects on hydrodynamic forces, respectively. In particular, the heave motion with two frequencies is also simulated to study the interactions between results at different frequencies. It is interesting to see the sum and difference frequency components and the envelopes in time histories as a result. For forces caused by forced sway or roll motions, there are only even-order harmonics for vertical forces and only odd-order harmonics for horizontal forces. Finally, a single body with combined sway, heave and roll motion is studied to examine the interactions between motion modes.

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8

Sourie, Aurélien, and Nicolas Chamel. "Generalization of the Kutta–Joukowski theorem for the hydrodynamic forces acting on a quantized vortex." International Journal of Modern Physics B 34, no. 10 (April 20, 2020): 2050099. http://dx.doi.org/10.1142/s021797922050099x.

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The hydrodynamic forces acting on a quantized vortex in a superfluid have long been a highly controversial issue. A new approach, originally developed in the astrophysical context of compact stars, is presented to determine these forces by considering small perturbations of the asymptotically uniform flows in the region far from the vortex in the framework of Landau–Khalatnikov two-fluid model. Focusing on the irrotational part of the flows in the Helmholtz decomposition, the classical Kutta–Joukowski theorem from ordinary hydrodynamics is thus generalized to superfluid systems. The same method is applied to predict the hydrodynamic forces acting on vortices in cold atomic condensates and superfluid mixtures.

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9

Verley, Richard L. P., Kostas F. Lambrakos, and Knut Reed. "Hydrodynamic Forces on Seabed Pipelines." Journal of Waterway, Port, Coastal, and Ocean Engineering 115, no. 2 (March 1989): 190–204. http://dx.doi.org/10.1061/(asce)0733-950x(1989)115:2(190).

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10

Isaacson, Michael, and John Baldwin. "Moored structures in waves and currents." Canadian Journal of Civil Engineering 23, no. 2 (April 1, 1996): 418–30. http://dx.doi.org/10.1139/l96-046.

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The present paper provides a brief review of the analysis of moored floating structures in waves and currents. A hydrodynamic analysis is required in order to predict wave and current effects on floating structures, and corresponding numerical models for determining transmitted and reflected wave heights, added masses, damping coefficients, and wave exciting forces are summarized. A mooring analysis is required in conjunction with the hydrodynamic analysis in order to calculate the restraint provided by the mooring system, as well as the structure motions, mooring line and anchor loads, and mooring line configurations. Various aspects of static, dynamic, and nonlinear responses are discussed and illustrated with example applications. Key words: coastal engineering, currents, floating structures, hydrodynamics, mooring forces, ocean engineering, wave forces, waves.

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11

Losada, M. A., R. Medina, and M. Alejo. "WAVE FORCES ON ARMOR BLOCKS." Coastal Engineering Proceedings 1, no. 21 (January 29, 1988): 184. http://dx.doi.org/10.9753/icce.v21.184.

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Experimental measurements of hydrodynamic forces on a cubic block near the bottom under solitary waves were carried out. Horizontal and vertical forces were recorded and instantaneous and averaged values of hydrodynamic coefficients CD, C„ and C,_ for different boundary conditions, gap between block and bottom, e, and two or three-dimensional flow, were obtained. Horizontal and vertical forces were found to depend strongly on e/D, where D is the block side . Instantaneous values of hydrodynamic coefficients vary considerably during the wave passage and differ appreciably from the averaged coefficients.

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12

Shabanian, Jaber, and Jamal Chaouki. "Performance of a Catalytic Gas–Solid Fluidized Bed Reactor in the Presence of Interparticle Forces." International Journal of Chemical Reactor Engineering 14, no. 1 (February 1, 2016): 433–44. http://dx.doi.org/10.1515/ijcre-2014-0106.

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AbstractThe influence of interparticle forces (IPFs) on the hydrodynamics of a gas–solid fluidized bed was experimentally investigated with the help of a polymer coating approach. The results showed that the presence of IPFs in the bed can considerably change the hydrodynamic parameters. The tendency of the fluidizing gas passing through the bed in the emulsion phase increased with IPFs in the bubbling regime. The performance of a fluidized bed reactor was then studied through simulation of a reactive catalytic system using three different hydrodynamic models: (a) a simple two-phase flow model, (b) a dynamic two-phase flow model, and (c) a dynamic two-phase flow model, integrating the effects of superficial gas velocity and IPFs. The simple two-phase flow model was found to underestimate the reactor performance for catalytic reaction most likely due to the oversimplified assumptions involved in this model. Also, the simulation results showed that modification of the bed hydrodynamics due to IPFs resulted in a better performance for a bubbling fluidized bed reactor. This suggests that the hydrodynamic models should take into account the effects of superficial gas velocity and variation in the ratio of the magnitude of IPFs/hydrodynamic forces, due to any operational reason, to yield a more reliable evaluation of the performance of the fluidized bed reactor.

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13

Mao, Hongfei, Yanli He, Guanglin Wu, Jinbo Lin, and Ran Ji. "Study of Liquid Viscosity Effects on Hydrodynamic Forces on an Oscillating Circular Cylinder Underwater Using OpenFOAM®." Symmetry 13, no. 10 (September 28, 2021): 1806. http://dx.doi.org/10.3390/sym13101806.

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By neglecting the viscosity of fluid and rotation in flow, the theory of potential flow cannot accurately predict the hydrodynamic forces on the structures under significant viscous effects. In this study, the effects of liquid viscosity on the hydrodynamic forces on a horizontal circular cylinder underwater with a large-amplitude forced oscillation were investigated. The study used a two-dimensional two-phase flow wave tank model based on the viscous fluid theory using the OpenFOAM® package. The numerical calculations were carried out under different types of liquid (i.e., liquid with different viscosities). The liquid viscosity effects are visually shown by comparison of the various frequency components of the hydrodynamic forces on the cylinder, and the magnitude and phase relations of the viscous shear forces and the pressure forces. By analyzing the distribution characteristics of the flow fields around the circular cylinder, the viscous-effect mechanisms are revealed. It is found that the discrepancies of the contributions of viscous shear forces, and the discrepancies of the vortex effects on the phase and magnitude of the pressure forces lead to the obvious differences among the results under different liquid viscosities.

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14

Akmal, Jamiatul, Asnawi Lubis, Ahmad Su'udi, Novri Tanti, Nurcahya Nugraha, Zaky Abyan Fahrain, and Panji Firmanul Hakim. "Hydrodynamic forces on submerged floating tube: The effect of curvature radius and depth level." Kapal: Jurnal Ilmu Pengetahuan dan Teknologi Kelautan 19, no. 1 (February 14, 2022): 1–8. http://dx.doi.org/10.14710/kapal.v19i1.44019.

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The discussion of hydrodynamic forces becomes an important issue in determining the dynamic behaviour of the Submerged Floating Tunnel Bridge (SFTB) structure. As stated in the Morison Equation, the hydrodynamic forces are affected by the kinematics of water particles, but up to this date, there are only a few discussions for curved tube applications. This paper discusses the effect of curvature radius and depth level on hydrodynamic forces to get the correction factor for a straight tube. Tubes with variations in radius curvature (R/L) and diameter (D) were installed in a wave pool with a depth level (z/d). The hydrodynamic forces were detected by a load cell sensor placed on a pedestal at the end of the specimen. The data from the load cell was processed by the data acquisition system and displayed on the monitor screen, showing that the z/d ratio and the R/L ratio both affect the hydrodynamic forces. A larger z/d ratio (deeper) results in smaller hydrodynamic forces, while a smaller R/L ratio (more curved) results in smaller hydrodynamic forces. A correction factor (C) has been determined to calculate the hydrodynamic force on a curved tube based on the Morison equation.

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15

Burton, D. A., J. Gratus, and R. W. Tucker. "Hydrodynamic forces on two moving discs." Theoretical and Applied Mechanics 31, no. 2 (2004): 153–88. http://dx.doi.org/10.2298/tam0402153b.

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We give a detailed presentation of a flexible method for constructing explicit expressions of irrotational and incompressible fluid flows around two rigid circular moving discs. We also discuss how such expressions can be used to compute the fluid-induced forces and torques on the discs in terms of Killing drives. Conformal mapping techniques are used to identify a meromorphic function on an annular region in C with a flow around two circular discs by a Mobius transformation. First order poles in the annular region correspond to vortices outside of the two discs. Inflows are incorporated by putting a second order pole at the point in the annulus that corresponds to infinity.

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16

OKAMOTO, Toshihiko, Masayoshi WATADO, Tomoya IWASHITA, and Hideo KIKKAWA. "Hydrodynamic Forces on Spherical Roughness Elements." PROCEEDINGS OF HYDRAULIC ENGINEERING 34 (1990): 493–98. http://dx.doi.org/10.2208/prohe.34.493.

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17

Poon, Eric K. W., Andrew S. H. Ooi, Matteo Giacobello, and Raymond C. Z. Cohen. "Hydrodynamic forces on a rotating sphere." International Journal of Heat and Fluid Flow 42 (August 2013): 278–88. http://dx.doi.org/10.1016/j.ijheatfluidflow.2013.02.005.

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18

Kalghatgi, S. G., and P. G. Sayer. "Hydrodynamic Forces on Piggyback Pipeline Configurations." Journal of Waterway, Port, Coastal, and Ocean Engineering 123, no. 1 (January 1997): 16–22. http://dx.doi.org/10.1061/(asce)0733-950x(1997)123:1(16).

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19

Bryndum, M. B., V. Jacobsen, and D. T. Tsahalis. "Hydrodynamic Forces on Pipelines: Model Tests." Journal of Offshore Mechanics and Arctic Engineering 114, no. 4 (November 1, 1992): 231–41. http://dx.doi.org/10.1115/1.2919975.

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An extensive model test program on the hydrodynamic forces on a submarine pipeline resting on the sea bottom and exposed to steady current, regular waves, combined steady current and regular waves, irregular waves, and combined steady current and irregular waves has been performed. The hydrodynamic forces in both the in-line and the cross-flow directions have been analyzed using three different methods, i.e., least-squares-fit analysis based on Morison-type equations, Fourier analysis, and maximum force analysis. The force coefficients associated with each method have been determined for a wide range of environmental conditions. The results of the tests are presented in terms of the calculated force coefficients and their dependence on various nondimensional parameters is discussed. Furthermore, comparisons with other test data are presented.

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20

Korobkin, A. A., T. I. Khabakhpasheva, and Kevin J. Maki. "Hydrodynamic forces in water exit problems." Journal of Fluids and Structures 69 (February 2017): 16–33. http://dx.doi.org/10.1016/j.jfluidstructs.2016.12.002.

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21

Monahan, Christopher, Ali Naji, Ronald Horgan, Bing-Sui Lu, and Rudolf Podgornik. "Hydrodynamic fluctuation-induced forces in confined fluids." Soft Matter 12, no. 2 (2016): 441–59. http://dx.doi.org/10.1039/c5sm02346g.

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Thermal hydrodynamic fluctuations in a classical, compressible, viscous fluid film give rise to fluctuation-induced forces between the no-slip fluid boundaries, whose average value is zero but their correlators are finite and represent a “secondary Casimir effect” in the hydrodynamic context.

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22

Hoh, N. J., and R. N. Zia. "Force-induced diffusion in suspensions of hydrodynamically interacting colloids." Journal of Fluid Mechanics 795 (April 20, 2016): 739–83. http://dx.doi.org/10.1017/jfm.2016.209.

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We study the influence of hydrodynamic, thermodynamic and interparticle forces on the diffusive motion of a Brownian probe driven by a constant external force through a dilute colloidal dispersion. The influence of these microscopic forces on equilibrium self-diffusivity (passive microrheology) is well known: all three act to hinder the short- and long-time self-diffusion. Here, via pair-Smoluchowski theory, we explore their influence on self-diffusion in a flowing suspension, where particles and fluid have been set into motion by an externally forced probe (active microrheology), giving rise to non-equilibrium flow-induced diffusion. The probe’s motion entrains background particles as it travels through the bath, deforming the equilibrium suspension microstructure. The shape and extent of microstructural distortion is set by the relative strength of the external force $F^{\mathit{ext}}$ to the entropic restoring force $kT/a_{\mathit{th}}$ of the bath particles, defining a Péclet number $\mathit{Pe}\equiv F^{\mathit{ext}}/(2kT/a_{\mathit{th}})$; and also by the strength of hydrodynamic interactions, set by the range of interparticle repulsion ${\it\kappa}=(a_{\mathit{th}}-a)/a$, where $kT$ is the thermal energy and $a_{\mathit{th}}$ and $a$ are the thermodynamic and hydrodynamic sizes of the particles, respectively. We find that in the presence of flow, the same forces that hinder equilibrium diffusion now enhance it, with diffusive anisotropy set by the range of interparticle repulsion ${\it\kappa}$. A transition from hindered to enhanced diffusion occurs when diffusive and advective forces balance, $\mathit{Pe}\sim 1$, where the exact value is a sensitive function of the strength of hydrodynamics, ${\it\kappa}$. We find that the hindered to enhanced transition straddles two transport regimes: in hindered diffusion, stochastic forces in the presence of other bath particles produce deterministic displacements (Brownian drift) at the expense of a maximal random walk. In enhanced diffusion, driving the probe with a deterministic force through an initially random suspension leads to fluctuations in the duration of probe–bath particle entrainment, giving rise to enhanced, flow-induced diffusion. The force-induced diffusion is anisotropic for all $\mathit{Pe}$, scaling as $D\sim \mathit{Pe}^{2}$ in all directions for weak forcing, regardless of the strength of hydrodynamic interactions. When probe forcing is strong, $D\sim \mathit{Pe}$ in all directions in the absence of hydrodynamic interactions, but the picture changes qualitatively as hydrodynamic interactions grow strong. In this nonlinear regime, microstructural asymmetry weakens while the anisotropy of the force-induced diffusion tensor increases dramatically. This behaviour owes its origins to the approach toward Stokes flow reversibility, where diffusion along the direction of probe force scales advectively while transverse diffusion must vanish.

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23

Sanders, Ross H. "Hydrodynamic Characteristics of a Swimmer’s Hand." Journal of Applied Biomechanics 15, no. 1 (February 1999): 3–26. http://dx.doi.org/10.1123/jab.15.1.3.

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The main purpose of this study was to develop a model for calculating forces produced by a swimmer’s hand, with the thumb adducted, accelerating in the direction of flow. The model included coefficients to account for the velocity and acceleration of the hand. These coefficients were designed to calculate forces in the direction opposite the motion (drag) and two components of lift orthogonal to the direction of motion. To determine the coefficients, three-dimensional forces acting on a resin cast of a swimmer’s hand were recorded while accelerating the hand from rest to 0.45 m · s−1 and 0.6 m · −1 in a towing tank. The hand orientation was varied throughout the entire range at 5° increments. Three-dimensional surfaces describing the magnitude of the coefficients as functions of pitch and sweepback angle were produced. It was found that acceleration coefficients as well as velocity coefficients are required for accurate modeling of the forces produced by the hand in swimming. The forces generated by the hand are greatest when pitch angles approach 90° due to the large contribution by the drag component. However, at pitch angles near 45° and sweepback angles near 45° and 135°, lift forces contribute substantially.

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24

Syrkin, V. V., Yu F. Galuza, I. A. Abramova, and V. A. Treyer. "Investigation of the dynamic stability of pressure regulators when taking into account the inertial forces of the hydraulic fluid flow." Journal of Physics: Conference Series 2182, no. 1 (March 1, 2022): 012066. http://dx.doi.org/10.1088/1742-6596/2182/1/012066.

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Abstract The dynamic stability of pressure regulators in hydraulic systems of technological machines is considered, in which additional hydrodynamic forces arise in unsteady modes. The magnitude of these hydrodynamic forces is determined mainly by the first derivative of the flow rate through the throttle slot of the regulator in time. Experimental studies of pressure regulators have shown that hydrodynamic forces, depending on the switching scheme and the design dimensions of these devices, can affect their stability in various ways.

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25

Kyozuka, Yusaku, Tsutomu Hori, and Wataru Koterayama. "Unsteady Hydrodynamic Forces on a Lifting Body." Journal of the Society of Naval Architects of Japan 1990, no. 168 (1990): 243–51. http://dx.doi.org/10.2534/jjasnaoe1968.1990.168_243.

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26

Kyozuka, Yusaku, Tsutomu Hori, and Wataru Koterayama. "Unsteady Hydrodynamic Forces on a Lifting Body." Journal of the Society of Naval Architects of Japan 1990, no. 167 (1990): 43–53. http://dx.doi.org/10.2534/jjasnaoe1968.1990.43.

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27

de Béjar, Luis A., and Richard L. Stockstill. "Hydrodynamic Forces on Spillway Torque-Tube Gates." Journal of Hydraulic Engineering 136, no. 10 (October 2010): 681–92. http://dx.doi.org/10.1061/(asce)hy.1943-7900.0000216.

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28

AKIYAMA, Shoichi, Hiroshi Tsukamoto, Koji MIYAZAKI, and Kazuhisa INADA. "Unsteady Hydrodynamic Forces on Diffuser Pump Shaft." Proceedings of Conference of Kyushu Branch 2003.56 (2003): 121–22. http://dx.doi.org/10.1299/jsmekyushu.2003.56.121.

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29

Isaacson, Michael. "Earthquake-induced hydrodynamic forces on reservoir roofs." Canadian Journal of Civil Engineering 37, no. 8 (August 2010): 1107–15. http://dx.doi.org/10.1139/l10-049.

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The present paper describes the hydrodynamic loads on the roof of a water-filled reservoir or storage tank due to earthquake-induced sloshing. Initially, the paper summarizes available solutions for the water surface elevation in a rectangular reservoir subjected to harmonic and earthquake base motions, and as well an available formulation for the force on the roof of a rectangular reservoir. With this background, a new formulation for the force on the roof is developed, and selected results based on this are presented. A recommended design procedure is thereby proposed, and an example application is provided. The potential extension of the proposed formulation to other reservoir configurations is discussed. Although a validation of the proposed formulation based on laboratory test results is needed, it is suggested that in the interim the proposed formulation is adopted for design.

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30

Chakrabarti, Subrata. "Hydrodynamic interaction forces on multi-moduled structures." Ocean Engineering 27, no. 10 (October 2000): 1037–63. http://dx.doi.org/10.1016/s0029-8018(99)00034-7.

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31

Lambrakos, K. F., J. C. Chao, H. Beckmann, and H. R. Brannon. "Wake model of hydrodynamic forces on pipelines." Ocean Engineering 14, no. 2 (January 1987): 117–36. http://dx.doi.org/10.1016/0029-8018(87)90073-4.

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32

Söylemez, M. "A general method for calculating hydrodynamic forces." Ocean Engineering 23, no. 5 (July 1996): 423–45. http://dx.doi.org/10.1016/0029-8018(95)00023-2.

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33

Shehata, Hisham M., Muhammad R. Hajj, Craig A. Woolsey, and Saad Ragab. "Effects of Flexible Propulsors on Hydrodynamic Forces." IFAC-PapersOnLine 52, no. 21 (2019): 14–20. http://dx.doi.org/10.1016/j.ifacol.2019.12.276.

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34

Akter, A., G. Pender, G. Wright, and M. Crapper. "Predicting the hydrodynamic forces on geobag revetments." Journal of Flood Risk Management 4, no. 4 (August 7, 2011): 328–38. http://dx.doi.org/10.1111/j.1753-318x.2011.01117.x.

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35

Hoh, N. J., and R. N. Zia. "Hydrodynamic diffusion in active microrheology of non-colloidal suspensions: the role of interparticle forces." Journal of Fluid Mechanics 785 (November 16, 2015): 189–218. http://dx.doi.org/10.1017/jfm.2015.602.

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Hydrodynamic diffusion in the absence of Brownian motion is studied via active microrheology in the ‘pure-hydrodynamic’ limit, with a view towards elucidating the transition from colloidal microrheology to the non-colloidal limit, falling-ball rheometry. The phenomenon of non-Brownian force-induced diffusion in falling-ball rheometry is strictly hydrodynamic in nature; in contrast, analogous force-induced diffusion in colloids is deeply connected to the presence of a diffusive boundary layer even when Brownian motion is very weak compared with the external force driving the ‘probe’ particle. To connect these two limits, we derive an expression for the force-induced diffusion in active microrheology of hydrodynamically interacting particles via the Smoluchowski equation, where thermal fluctuations play no role. While it is well known that the microstructure is spherically symmetric about the probe in this limit, fluctuations in the microstructure need not be – and indeed lead to a diffusive spread of the probe trajectory. The force-induced diffusion is anisotropic, with components along and transverse to the line of external force. The latter is identically zero owing to the fore–aft symmetry of pair trajectories in Stokes flow. In a naïve first approach, the vanishing relative hydrodynamic mobility at contact between the probe and an interacting bath particle was assumed to eliminate all physical contribution from interparticle forces, whereby advection alone drove structural evolution in pair density and microstructural fluctuations. With such an approach, longitudinal force-induced diffusion vanishes in the absence of Brownian motion, a result that contradicts well-known experimental measurements of such diffusion in falling-ball rheometry. To resolve this contradiction, the probe–bath-particle interaction at contact was carefully modelled via an excluded annulus. We find that interparticle forces play a crucial role in encounters between particles in the hydrodynamic limit – as they must, to balance the advective flux. Accounting for this force results in a longitudinal force-induced diffusion $D_{\Vert }=1.26aU_{S}{\it\phi}$, where $a$ is the probe size, $U_{S}$ is the Stokes velocity and ${\it\phi}$ is the volume fraction of bath particles, in excellent qualitative and quantitative agreement with experimental measurements in, and theoretical predictions for, macroscopic falling-ball rheometry. This new model thus provides a continuous connection between micro- and macroscale rheology, as well as providing important insight into the role of interparticle forces for diffusion and rheology even in the limit of pure hydrodynamics: interparticle forces give rise to non-Newtonian rheology in strongly forced suspensions. A connection is made between the flow-induced diffusivity and the intrinsic hydrodynamic microviscosity which recovers a precise balance between fluctuation and dissipation in far from equilibrium suspensions; that is, diffusion and drag arise from a common microstructural origin even far from equilibrium.

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36

Zhao, Enjin, Lin Mu, and Bing Shi. "Numerical Study of the Influence of Tidal Current on Submarine Pipeline Based on the SIFOM–FVCOM Coupling Model." Water 10, no. 12 (December 10, 2018): 1814. http://dx.doi.org/10.3390/w10121814.

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The interaction between coastal ocean flows and the submarine pipeline involved with distinct physical phenomena occurring at a vast range of spatial and temporal scales has always been an important research subject. In this article, the hydrodynamic forces on the submarine pipeline and the characteristics of tidal flows around the pipeline are studied depending on a high-fidelity multi-physics modeling system (SIFOM–FVCOM), which is an integration of the Solver for Incompressible Flow on the Overset Meshes (SIFOM) and the Finite Volume Coastal Ocean Model (FVCOM). The interactions between coastal ocean flows and the submarine pipeline are numerically simulated in a channel flume, the results of which show that the hydrodynamic forces on the pipeline increase with the increase of tidal amplitude and the decrease of water depth. Additionally, when scour happens under the pipeline, the numerical simulation of the suspended pipeline is also carried out, showing that the maximum horizontal hydrodynamic forces on the pipeline reduce and the vertical hydrodynamic forces grow with the increase of the scour depth. According to the results of the simulations in this study, an empirical formula for estimating the hydrodynamic forces on the submarine pipeline caused by coastal ocean flows is given, which might be useful in engineering problems. The results of the study also reveal the basic features of flow structures around the submarine pipeline and its hydrodynamic forces caused by tidal flows, which contributes to the design of submarine pipelines.

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37

Zhang, Wanchao, Yang Zhu, Shuxu Liu, Jianhua Wang, and Wentian Zhang. "Evaluation of Geometrical Influence on the Hydrodynamic Characteristics and Power Absorption of Vertical Axisymmetric Wave Energy Converters in Irregular Waves." Polish Maritime Research 30, no. 2 (June 1, 2023): 130–45. http://dx.doi.org/10.2478/pomr-2023-0029.

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Abstract To obtain the mechanical energy of waves from arbitrary directions, the vibration absorbers of wave energy converters (WEC) are usually vertically axisymmetric. In such case, the wave-body interaction hydrodynamics is an essential research topic to obtain high-efficiency wave energy. In this paper, a semi-analytical method of decomposing the complex axisymmetric boundary into several ring-shaped stepped surfaces based upon the boundary approximation method (BAM) is introduced and examined. The hydrodynamic loads and parameters, such as the wave excitation forces, added mass and radiation damping of the vertical axisymmetric oscillating buoys, can then be achieved by using the new boundary discretisation method. The calculations of the wave forces and hydrodynamic coefficients show good convergence with the number of discretisation increases. Comparison between the constringent results and the results of the conventional method also verifies the feasibility of the method. Then, simulations and comparisons of the hydrodynamic forces, motions and wave power conversions of the buoys with series draught and displacement ratios in regular and irregular waves are conducted. The calculation results show that the geometrical shape has a great effect on the hydrodynamic and wave power conversion performance of the absorber. In regular waves, though the concave buoy has the lowest wave conversion efficiency, it has the largest frequency bandwidth for a given draught ratio, while in irregular waves, for a given draught ratio, the truncated cylindrical buoy has the best wave power conversion, and for a given displacement of the buoy, the concave buoy shows the best wave power conversion ability.

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Dabssi, Noureddine, Mohamed Chagdali, and Alain Hémon. "HYDRODYNAMIC COEFFICIENTS AND FORCES ON MULTIHULLS IN SHALLOW WATER WITH CONSTANT OR VARIABLE DEPTH." TRANSPORT 23, no. 3 (September 30, 2008): 245–52. http://dx.doi.org/10.3846/1648-4142.2008.23.245-252.

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Numerical and hydro dynamical procedures are developed to compute bidimensional hydrodynamic coefficients and forces on multihulls associated with harmonic oscillations in shallow water with constant or variable depth. The forces are composed of two parts and include the sum of incident and diffracted forces and hydrodynamic reaction. The latter one is used to determinate the hydrodynamic coefficients (added mass and damping). The numerical method used is the Boundary Element Method. We can compute flow around multihulls sections. An application to cylindrical, right triangular and rectangular hull forms is presented.

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Burelbach, Jérôme, David B. Brückner, Daan Frenkel, and Erika Eiser. "Thermophoretic forces on a mesoscopic scale." Soft Matter 14, no. 36 (2018): 7446–54. http://dx.doi.org/10.1039/c8sm01132j.

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Liu, Yi, Lu Zou, and Zao-Jian Zou. "Computational fluid dynamics prediction of hydrodynamic forces on a manoeuvring ship including effects of dynamic sinkage and trim." Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment 233, no. 1 (November 14, 2017): 251–66. http://dx.doi.org/10.1177/1475090217734685.

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Understanding the manoeuvring performance of a ship requires accurate predictions of the hydrodynamic forces and moments on the ship. In the present study, the hydrodynamic forces and moments on a manoeuvring container ship at various rudder and drift angles are numerically predicted by solving the unsteady Reynolds-averaged Navier–Stokes equations. The effects of dynamic sinkage and trim on the hydrodynamic forces are first investigated together with a grid dependency study to estimate the numerical error and uncertainty caused by grid discretization, and with a validation study combining the experimental data. The results show that the effect of dynamic sinkage and trim is non-negligible, since including it improves the hydrodynamic force predictions and reduces the numerical error and uncertainty, and the averaged error and uncertainty are smaller than the other computational fluid dynamics results where sinkage and trim were fixed with given values from model tests. Therefore, it is included in the subsequent systematic simulations regarding the influence of rudder and drift angles. The computed forces, moments and rudder coefficients at different rudder and drift angles on the container ship are compared with the benchmark model test data. From the computations, all the predicted quantities are in satisfactory agreement with the experimental data. The details of the flow filed and hydrodynamic forces, such as pressure distributions, transverse force distributions along the hull, velocity contours, streamlines and wave patterns are presented and discussed, and a deep insight into the physical mechanism in the hydrodynamic forces on a manoeuvring ship is obtained.

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Bozorgnia, Mehrdad, Jiin-Jen Lee, and Frederic Raichlen. "WAVE STRUCTURE INTERACTION: ROLE OF ENTRAPPED AIR ON WAVE IMPACT AND UPLIFT FORCES." Coastal Engineering Proceedings 1, no. 32 (January 26, 2011): 57. http://dx.doi.org/10.9753/icce.v32.structures.57.

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In present paper, a numerical wave load model based on compressible two-phase Navier Stokes type equations is used to evaluate hydrodynamic forces exerted on I-10 bridge across Mobil Bay which was extensively damaged during Hurricane Katrina. The volume of fluid method (VOF) is used in the model to describe dynamic free surface which is capable of simulating complex discontinuous free surface associated with wave-deck interactions. Special emphasis was put on investigating the role of entrapped air on hydrodynamic forces exerted on bridge superstructure. Numerical simulation results indicate that air entrapment can significantly amplify uplift forces applied to the bridge superstructure. To mitigate hydrodynamic forces, effectiveness of airvents is investigated. It has been shown that airvents can significantly damp out wave energy and can effectively reduce uplift forces.

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Tarbiat, Saman, Hassan Ghassemi, and Manouchehr Fadavie. "Numerical Prediction of Hydromechanical Behaviour of Controllable Pitch Propeller." International Journal of Rotating Machinery 2014 (2014): 1–7. http://dx.doi.org/10.1155/2014/180725.

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The research described in this paper was carried out to predict hydrodynamic and frictional forces of controllable pitch propeller (CPP) that bring about fretting problems in a blade bearing. The governing equations are Reynolds-averaged Navier-Stokes (RANS) and are solved by OpenFOAM solver for hydrodynamic forces behind the ship’s wake. Frictional forces are calculated by practical mechanical formulae. Different advance velocities with constant rotational speed for blades are used to achieve hydrodynamic coefficients in open water and the wake behind the propeller. Results are compared at four different pitches. Detailed numerical results of 3D modelling of the propeller, hydrodynamic characteristics, and probability of the fretting motion in the propeller are presented. Results show that the probability of the fretting movement is related to the pitch.

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Yuan, Jinzhou, David M. Raizen, and Haim H. Bau. "A hydrodynamic mechanism for attraction of undulatory microswimmers to surfaces (bordertaxis)." Journal of The Royal Society Interface 12, no. 109 (August 2015): 20150227. http://dx.doi.org/10.1098/rsif.2015.0227.

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Although small nematodes significantly impact human and animal health, agriculture, and ecology, little is known about the role of hydrodynamics in their life cycles. Using the nematode Caenorhabditis elegans as a model undulatory microswimmer, we have observed that animals are attracted to and swim along surfaces. The attraction to surfaces does not require mechanosensory neuron function. In dilute swarms, swimmers aggregate near surfaces. Using resistive force-based theory, symmetry arguments, and direct hydrodynamic simulations, we demonstrate that forces resulting from the interaction between the swimmer-induced flow field and a nearby surface cause a short-range hydrodynamic torque that stirs the swimmers towards the surface. When combined with steric forces, this causes locomotion along the surface. This surface attraction may affect nematode mate and food finding behaviour and, in the case of parasitic nematodes, may facilitate host penetration. Surface attraction must be accounted for when studying animals' responses to various stimuli, and suggests means of controlling undulatory microswimmers.

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Zhou, Xueqian, Cong Liu, Huilong Ren, and Chen Xu. "Numerical Analysis of Propeller-Induced Hydrodynamic Interaction between Ships." Journal of Marine Science and Engineering 11, no. 3 (March 1, 2023): 537. http://dx.doi.org/10.3390/jmse11030537.

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The hydrodynamic interaction effects between ships are significantly pronounced in restricted waters, and this may potentially threaten the safety of ships, especially given that ship dimensions and waterway traffic have kept increasing. Although there has been a good amount of research on ship hydrodynamic interactions, the study of the effect of the propeller on the ship’s hydrodynamic interaction is very limited. In this paper, a series of RANSE-based numerical simulations are carried out to study the characteristics of the propeller in near-field interaction between ships without speed. The hydrodynamic forces and moment acting on the ship are calculated and analyzed. Through the analysis of the characteristics of the flow field and the behavioral pattern of the hydrodynamic forces, it is found that the propeller has a significant influence on the pressure distribution on the hull as well as on the hydrodynamic interaction forces. The maximum lateral force acting on the interacting ship could reach 0.58 times the standard thrust of a KP458 propeller (the revolution is 594 rpm and the velocity coefficient is 0.25 in open water).

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Shahlarly, M. E. "The study of hydrodynamic forces effecting submarine riser in 300 m depth in the Caspian Sea." Azerbaijan Oil Industry, no. 10 (October 15, 2022): 60–64. http://dx.doi.org/10.37474/0365-8554/2022-10-60-64.

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The subsea pipelines play a significant role in secure transportation of oil, gas and other energetic resources from the seabed to the shore and bases. The research of the hydrodynamic forces in the subsea pipelines and risers is a key factor from the point of view of regularity and efficiency of technological processes. The paper studies the impact of hydrodynamic forces affecting the subsea pipelines in the Caspian Sea. For diameter and thickness of pipe wall selected according to the ASME B36.10 standard, the forces of wind, wave and current, as well as the combination of forces affecting it were studied. The research was carried out in SACS computer software for three cases; as a result, the simulation and a table of force combinations for the optimum and unwanted occurrences appearing due to the impact of hydrodynamic forces and load combination were developed.

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Iyalla, Ibiye, Mamdud Hossain, and Jesse Andrawus. "Calculating Hydrodynamic Loads on Pipelines and Risers: Practical Alternative to Morison’s Equation." Advanced Materials Research 367 (October 2011): 431–38. http://dx.doi.org/10.4028/www.scientific.net/amr.367.431.

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Hydrodynamic stability analysis is one of the major tasks in the design of subsea pipelines and risers. The analysis is important to ensure stability of pipelines and risers under the action of the hydrodynamic forces produced by waves and currents during construction and operation stages. Morison related these hydrodynamic forces to kinematic wave properties, water particle velocity, and acceleration. However, previous studies show that Morison’s equation does not describe accurately the forces for combined wave and steady current flow. The actual measured forces differ significantly from the forces calculated using Morison’s equation. Though Morison’s equation leads to easy computer application for design purposes, it is a very conservative approach resulting in high cost of construction of offshore structures. In this paper the Wake II Model is incorporated into MathCAD software to practically determine hydrodynamic forces acting on cylindrical offshore structures. The Wake II Model takes into account the vortex shedding effect in the wake of a bluff body resulting in velocity reversal, thus the velocity is modified to include this effect. The modified velocity, time dependent drag and lift coefficients are then used to calculate hydrodynamic forces of lift and drag using MathCAD software. The results showed that the forces predicted using the Wake II Model is significantly less in comparison to the Morison’s equation. The results achieved in this project are consistent with results achieved by Lambrakos in his comparison of the Wake Model predictions with measured forces (actual loads) from the Exxon Pipeline Field Measurement Project (PFMP). The Wake II Model lends itself to easy computer application such as MathCAD so ftware and will also reduce the overall construction cost of cylindrical offshore structures such as pipelines and risers.

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O'Donnell, Michael J., and Mark W. Denny. "Hydrodynamic forces and surface topography: Centimeter-scale spatial variation in wave forces." Limnology and Oceanography 53, no. 2 (March 2008): 579–88. http://dx.doi.org/10.4319/lo.2008.53.2.0579.

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FAN, JIZHUANG, WEI ZHANG, YANHE ZHU, and JIE ZHAO. "CFD-BASED SELF-PROPULSION SIMULATION FOR FROG SWIMMING." Journal of Mechanics in Medicine and Biology 14, no. 06 (December 2014): 1440012. http://dx.doi.org/10.1142/s0219519414400120.

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Mechanism analysis of frog swimming is an interesting subject in the field of biofluid mechanics and bionics. Computing the hydrodynamic forces acting on a frog is difficult due to its characteristics of explosive propulsion and large range of joint motion. To analyze the flow around the body and vortices in the wake, in this paper, the method based on Computational Fluid Dynamics (CFD) was utilized to solve the velocity and pressure distributions in the flow field and on the frog. The hydrodynamic problem during the propulsive phase of a frog, Xenopus laevis, was calculated using the CFD software FLUENT. A self-propulsion simulation was performed which computed the body velocity from the joint trajectory input and CFD solved the hydrodynamic forces, and visual CFD results of the hydrodynamic forces and flow field structures were obtained.

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Bennaya, Mohamed, Wen Ping Zhang, and Moutaz M. Hegaze. "Estimation of the Induced Hydrodynamic Periodic Forces of Marine Propeller under Non-Uniform Inflow via CFD." Applied Mechanics and Materials 467 (December 2013): 293–99. http://dx.doi.org/10.4028/www.scientific.net/amm.467.293.

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In this work, both steady and unsteady Reynolds-Averaged Navier Stokes (RANS) simulations have been used via FLUENT software to calculate the induced 3-D hydrodynamic forces and moments of marine propeller. Marine propeller is excited by variation of hydrodynamic loading due to its operation in non-uniform wake field. The induced hydrodynamic forces and moments are calculated for single blade and for all blades at low Reynolds number under two operating conditions. The first one, uniform inflow is considered at the inlet. The second one, non-uniform inflow is considered at the inlet (under the wake effect of the ship) to represent the propeller-ship interaction. Unsteady results show that, due to non-uniform inflow every single blade is suffering from periodic forces and moments with fluctuation amplitude and harmonies higher than that applied on the propeller shaft but with lower frequency. The moments in vertical and transversal directions My and Mz are higher than the axial moment Mx. This study shows that, using Computational Fluid Dynamics (CFD) to solve RANS equation is a reliable tool for calculating the hydrodynamic characteristics and estimating the excited hydrodynamic forces due to propeller-ship interaction.

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Smoker, Brendan, Bart Stockdill, and Peter Oshkai. "Escort Tug Performance Prediction Using Computational Fluid Dynamics." Journal of Ship Research 60, no. 02 (June 1, 2016): 61–77. http://dx.doi.org/10.5957/jsr.2016.60.2.61.

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In this paper, we outline and validate a computational fluid dynamics (CFD) method for determining the hydrodynamic forces of an escort tug in indirect towing mode. We consider a range of yaw angles from 0° to 90° and a travel speed of 8 knots. We discuss the effects of scaling on prediction of flow separation and hydrodynamic forces acting on the vessel by carrying out CFD studies on both model and full-scale escort tugs performing indirect escort maneuvers. As the escort performance in terms of maximum steering forces is strongly dependent on the onset of flow separation from the hull and skeg of the tug, the model-scale simulations under-predict the maximum steering force by 12% relative to the full-scale simulations. In addition, we provide a method for converting the hydrodynamic forces of the CFD escort study into towline and thrust forces.

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Journal articles on the topic 'Hydrodynamic Forces'

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