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Relevant bibliographies by topics / Hydrodynamic formulation

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Academic literature on the topic 'Hydrodynamic formulation'

Author: Grafiati

Published: 4 June 2021

Last updated: 13 February 2022

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Journal articles on the topic "Hydrodynamic formulation"

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Smith, Arlynn W., and Kevin F. Brennan. "Comparison of Non-Parabolic Hydrodynamic Models Based On Different Band Structure Models." VLSI Design 6, no. 1-4 (1998): 177–80. http://dx.doi.org/10.1155/1998/71521.

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This paper presents two non-parabolic hydrodynamic model formulations suitable for the simulation of inhomogeneous semiconductor devices. The first formulation uses the Kane dispersion relationship, (ℏk)2/2m = W(1+αW). The second formulation makes use of a power law, (ℏk)2/2m = xWy, for the dispersion relation. The non-parabolicity and energy range of the hydrodynamic model based on the Kane dispersion relation is limited. The power law formulation produces closed form coefficients similar to those under the parabolic band approximation but the carrier concentration can deviate. An extended power law dispersion relation is proposed to account for band structure effects, (ℏk)2/2m = xW1+yW. This dispersion relation closely matches the calculated band structure over a wide energy range and may lead to closed form coefficients for the hydrodynamic model.

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Avital, E. J., M. Alonso, and V. Supontisky. "Computational aeroacoustics: The low speed jet." Aeronautical Journal 112, no. 1133 (2008): 405–14. http://dx.doi.org/10.1017/s0001924000002360.

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AbstractLow speed circular, elliptic and planar jets are investigated computationally for basic sound generation and hydrodynamics. The jets are assumed to be incompressible and are simulated using the large eddy simulation (LES) approach. The emitted sound is calculated using Lighthill’s acoustic analogy. Two formulations are used, Lighthill’s stress tensor formulation and Powell’s vortex sound formulation. A new boundary correction for Powell’s formulation is developed in order to account for the finite size of the computational domain. Low to moderate Reynolds number jets are simulated. Good agreement with known hydrodynamic results is achieved. This includes the nature of the transition process, e.g. enhanced mixing and axis switching in the elliptic jet and in some statistical results. The new boundary correction for Powell’s formulation proves to be vital in order to achieve good agreement with Lighthill’s formulation. Some success in high frequency prediction at least for the circular and elliptic jets is achieved in terms of getting the expected asymptotic behaviour. Both formulations show that the elliptic jet noise level is mildly lower than the circular jet noise level. Good to very good agreement is achieved in terms of directivities and frequency spectra with known results for the various jets.

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Sorek, Shaul, and Vyacheslav Borisov. "Modified Eulerian–Lagrangian formulation for hydrodynamic modeling." Journal of Computational Physics 231, no. 8 (2012): 3083–100. http://dx.doi.org/10.1016/j.jcp.2011.12.005.

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Isaacson, Michael. "Earthquake-induced hydrodynamic forces on reservoir roofs." Canadian Journal of Civil Engineering 37, no. 8 (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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Wang, Lian-Ping, Orlando Ayala, Scott E. Kasprzak, and Wojciech W. Grabowski. "Theoretical Formulation of Collision Rate and Collision Efficiency of Hydrodynamically Interacting Cloud Droplets in Turbulent Atmosphere." Journal of the Atmospheric Sciences 62, no. 7 (2005): 2433–50. http://dx.doi.org/10.1175/jas3492.1.

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Abstract A methodology for conducting direct numerical simulations (DNSs) of hydrodynamically interacting droplets in the context of cloud microphysics has been developed and used to validate a new kinematic formulation capable of describing the collision rate and collision efficiency of cloud droplets in turbulent air. The theoretical formulation is formally the same as the formulation recently developed for geometrical collision rate of finite-inertia, nonsettling particles. It is shown that its application to hydrodynamically interacting droplets requires corrections because of a nonoverlap requirement. An approximate method for correcting the kinematic properties has been developed and validated against DNS data. The formulation presented here is more general and accurate than previously published formulations that, in most cases, are some extension to the description of hydrodynamic–gravitational collision. General dynamic and kinematic representations of the properly defined collision efficiency in a turbulent flow have been discussed. In addition to augmenting the geometric collision rate, air turbulence has been found to enhance the collision efficiency because, in a turbulent flow, hydrodynamic interactions become less effective in reducing the average relative radial velocity. The level of increase in the collision efficiency depends on the flow dissipation rate. For example, the collision efficiency between droplets of 20 and 25 μm in radii is increased by 59% and 10% by air turbulence at dissipation rates of 400 and 100 cm2 s−3, respectively. It is also shown that hydrodynamic interactions lead to higher droplet concentration fluctuations. The formulation presented here separates the effect of turbulence on collision efficiency from the previously observed effect of turbulence on the geometric collision rate.

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Kerr, Daniel C., Neil Goldsman, and Isaak D. Mayergoyz. "Three-Dimensional Hydrodynamic Modeling of MOSFET Devices." VLSI Design 6, no. 1-4 (1998): 261–65. http://dx.doi.org/10.1155/1998/60859.

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The hydrodynamic (HD) model of semiconductor devices is solved numerically in three-dimensions (3-D) for the MOSFET device. The numerical instabilities of the HD model are analyzed to develop a stable discretization. The formulation is stabilized by using a new, higher-order discretization for the relaxation-time approximation (RTA) term of the energy-balance (EB) equation. The developed formulation is used to model the MOSFET.

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Burghardt, I., and L. S. Cederbaum. "Hydrodynamic equations for mixed quantum states. I. General formulation." Journal of Chemical Physics 115, no. 22 (2001): 10303. http://dx.doi.org/10.1063/1.1416493.

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Yang, Ciann-Dong. "A new hydrodynamic formulation of complex-valued quantum mechanics." Chaos, Solitons & Fractals 42, no. 1 (2009): 453–68. http://dx.doi.org/10.1016/j.chaos.2009.01.010.

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Lee, M., and Y. J. Cho. "On the migration of smooth particle hydrodynamic formulation in Cartesian coordinates to the axisymmetric formulation." Journal of Strain Analysis for Engineering Design 46, no. 8 (2011): 879–86. http://dx.doi.org/10.1177/0309324711409656.

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The smooth particle hydrodynamic (SPH) method has been extended for application to large deformation problems such as high velocity impacts by including the effect of material strength. This paper presents a simple modification of the kernel function that allows the SPH formulation in Cartesian coordinates to be migrated into an axisymmetric formulation. The proposed procedure is first applied to analyse transient deformations of a cylindrical rod impacting a rigid wall (Taylor impact test). A good agreement with published experimental data for the deformed shape is obtained. A sensitivity study of the key parameters required in the SPH formulation is conducted to provide better insight into the SPH modelling approach. Impacts between two bodies at high speed have also been simulated using an axisymmetric SPH code.

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Intartaglia, Carmela, Leonardo Soria, and Maurizio Porfiri. "Hydrodynamic coupling of two sharp-edged beams vibrating in a viscous fluid." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 470, no. 2162 (2014): 20130397. http://dx.doi.org/10.1098/rspa.2013.0397.

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In this paper, we study flexural vibrations of two thin beams that are coupled through an otherwise quiescent viscous fluid. While most of the research has focused on isolated beams immersed in placid fluids, inertial and viscous hydrodynamic coupling is ubiquitous across a multitude of engineering and natural systems comprising arrays of flexible structures. In these cases, the distributed hydrodynamic loading experienced by each oscillating structure is not only related to its absolute motion but is also influenced by its relative motion with respect to the neighbouring structures. Here, we focus on linear vibrations of two identical beams for low Knudsen, Keulegan–Carpenter and squeeze numbers. Thus, we describe the fluid flow using unsteady Stokes hydrodynamics and we propose a boundary integral formulation to compute pertinent hydrodynamic functions to study the fluid effect. We validate the proposed theoretical approach through experiments on centimetre-size compliant cantilevers that are subjected to underwater base-excitation. We consider different geometric arrangements, beam interdistances and excitation frequencies to ascertain the model accuracy in terms of the relevant non-dimensional parameters.

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Dissertations / Theses on the topic "Hydrodynamic formulation"

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Kernot, Matthew Peter. "The second-order forcing and response of offshore structures in irregular seas." Thesis, University of Oxford, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306887.

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Ganga, Dharan Deepak. "Numerical Analysis of End-Sealed Squeeze-Film Damper Bearings using Moving Reference Frame Formulation." University of Cincinnati / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1470741953.

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Vidmar, Rodrigo. "Formulação hidrodinâmica para a equação de Schrödinger não-linear e não-local em condensados de Bose-Einstein." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2017. http://hdl.handle.net/10183/163724.

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Será explorada a versão hidrodinâmica da equação de Schrödinger não-linear e não-local, descrevendo condensados de Bose-Einstein com auto-interações de longo alcance. Tais sistemas têm despertado interesse tendo em vista a busca da realização da condensação de Bose-Einstein sem necessidade de um potencial externo confinante e nos quais as interações atômicas locais não são suficientes. Para obter a descrição hidrodinâmica, a transformação de Madelung para a função de onda será utilizada, reduzindo o problema a uma equação da continuidade e a uma equação de transporte de momentum. Esta última é similar à equação de Euler em fluidos ideais, porém contendo um potencial quântico efetivo e um termo não local, o qual advém da interação atômica. Tais equações de fluido traduzem, respectivamente, a conservação da probabilidade e do momentum total. O método hidrodinâmico permitirá o estudo de excitações elementares, entre os quais os modos de Bogoliubov, segundo uma abordagem macroscópica.<br>The hydrodynamic version of the Schrödinger equation nonlinear and nonlocal will be explored, describing Bose-Einstein condensates with long-range self-interactions. Such systems have aroused interest with a view to pursuing the realization of Bose-Einstein condensation without an external confining potential and in which local atomic interactions are not enough. For the hydrodynamic description, the eikonal decomposition of the wave function is used, reducing the problem to one equation of continuity and to a transport of momentum equation. The latter is similar to the Euler equation in ideal fluid but containing an effective quantum potential and a nonlocal term, which comes from the atomic interaction. Such fluid equations translate, respectively, conservation of probability and total momentum. The hydrodynamic method will allow the study of elementary excitations, including Bogoliubov modes according to a macroscopic approach.

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Zhang, Shiqiong. "Formulation and application of numerical schemes in surface water flows /." View abstract or full-text, 2003. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202003%20ZHANGS.

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Maghzian, Hamid. "Simulation of hydrodynamics of the jet impingement using Arbitrary Lagrangian Eulerian formulation." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/421.

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Controlled cooling is an important part of steel production industry that affects the properties of the outcome steel. Many of the researches done in controlled cooling are experimental. Due to progress in the numerical techniques and high cost of experimental works in this field the numerical work seems more feasible. Heat transfer analysis is the necessary element of successful controlled cooling and ultimately achievement of novel properties in steel. Heat transfer on the surface of the plate normally contains different regimes such as film boiling, nucleate boiling, transition boiling and radiation heat transfer. This makes the analysis more complicated. In order to perform the heat transfer analysis often empirical correlations are being used. In these correlations the velocity and pressure within the fluid domain is involved. Therefore in order to obtain a better understanding of heat transfer process, study of hydrodynamics of the fluid becomes necessary. Circular jet due to its high efficiency has been used vastly in the industry. Although some experimental studies of round jet arrays have been done, yet the characteristics of a single jet with industrial geometric and flow parameters on the surface of a flat plate is not fully understood. Study of hydrodynamics of the jet impingement is the first step to achieve better understanding of heat transfer process. Finite element method as a popular numerical method has been used vastly to simulate different domains. Traditional approaches of finite element method, Lagrangian and Eulerian, each has its own benefits and drawbacks. Lagrangian approach has been used widely in solid domains and Eulerian approach has been widely used in fluid fields. Jet impingement problem, due to its unknown free surface and the change in the boundary, falls in the category of special problems and none of the traditional approaches is suitable for this application. The Arbitrary Lagrangian Eulerian (ALE) formulation has emerged as a technique that can alleviate many of the shortcomings of the traditional Lagrangian and Eulerian formulations in handling these types of problems. Using the ALE formulation the computational grid need not adhere to the material (Lagrangian) nor be fixed in space (Eulerian) but can be moved arbitrarily. Two distinct techniques are being used to implement the ALE formulation, namely the operator split approach and the fully coupled approach. This thesis presents a fully coupled ALE formulation for the simulation of flow field. ALE form of Navier-Stokes equations are derived from the basic principles of continuum mechanics and conservation laws in the fluid. These formulations are then converted in to ALE finite element equations for the fluid flow. The axi-symmetric form of these equations are then derived in order to be used for jet impingement application. In the ALE Formulation as the mesh or the computational grid can move independent of the material and space, an additional set of unknowns representing mesh movement appears in the equations. Prescribing a mesh motion scheme in order to define these unknowns is problem-dependent and has not been yet generalized for all applications. After investigating different methods, the Winslow method is chosen for jet impingement application. This method is based on adding a specific set of partial differential Equations(Laplace equations) to the existing equations in order to obtain enough equations for the unknowns. Then these set of PDEs are converted to finite element equations and derived in axi-symmetric form to be used in jet impingement application. These equations together with the field equations are then applied to jet impingement problem. Due to the number of equations and nonlinearity of the field equations the solution of the problem faces some challenges in terms of convergence characteristics and modeling strategies. Some suggestions are made to deal with these challenges and convergence problems. Finally the numerical treatment and results of analyzing hydrodynamics of the Jet Impingement is presented. The work in this thesis is confined to the numerical simulation of the jet impingement and the specifications of an industrial test setup only have been used in order to obtain the parameters of the numerical model.

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Politis, Konstantinos. "Développement de modèles numériques de tension superficielle pour la simulation d'écoulements avec interface à l'aide d'une formulation multi-fluides." Thesis, Ecole centrale de Nantes, 2016. http://www.theses.fr/2016ECDN0021.

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Les méthodes de lubrification par injection d'air sont considérées par la communauté scientifique comme la principale percée technologique à venir pour la réduction de la trainée des navires de commerce. A cette fin, il est impératif de modéliser finement les phénomènes physiques en jeu dans la lubrification par injection d'air, qui intègrent la représentation précise de la tension superficielle, des instabilités d'interface et des écoulements avec entraînement d'air. Au cours de ce travail, nous nous sommes attachés au développement d'outils de programmation, de schémas de reconstruction d'interface et de modélisations de tension superficielle dans le code de calcul ISIS-CFD. Deux nouvelles méthodes de calcul de la tension superficielle sont présentées. Elles utilisent un schéma de reconstruction globale de l'interface et sont couplées avec les schémas de discrétisation compressifs de la fraction volumique utilisés dans la formulation volumes finis non structurés sur laquelle est basé le code ISIS-CFD. Les résultats démontrent que des interactions dynamiques complexes, d'une ou plusieurs interfaces, peuvent être modélisées de façon précise. Ce travail permet d'envisager la réalisation ultérieure de calcul d'écoulements sur des navires lubrifiés par injection d'air, d’améliorer la compréhension physique et de contribuer à la modélisation macroscopique de modèles d'entraînement<br>Air Lubrication methods are regarded by the scientific community as the next major technological breakthrough in Naval Engineering to achieve the reduction of drag in commercial vessels. The accurate modeling of the physical phenomena governing the drag reduction mechanisms of Air Lubrication methods, namely, the dynamics of surface tension, the instabilities of the air-water interfaces and air entrainment, are imperative for the design of air-lubricated hulls. To that end, we have implemented to ISIS-CFD several programming tools, interface reconstruction schemes and surface tension modeling. Two new surface tension methods were developed. Both use a global interface reconstruction scheme and are coupled with the compressive discretization volume fraction schemes for the unstructured finite volume formulation that the flow solver ISIS-CFD is based on. The results demonstrate that complicated dynamic interactions of either a single or multiple interfaces can be accurately captured. In the context of a future research study, the proposed approaches could lead to the further enhancement of the modeling capabilities of ISISCFD by introducing a macroscopic air entrainment model and eventually the assessment of different physical effects encountered in lubricated naval vessels using ISIS-CFD

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Marioni, Luca. "Modélisation numerique et couplage électromagnétique-CFD dans les procédés decoulée." Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLEM011/document.

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Beaucoup de procédés utilisés dans l'industrie sidérurgique (coulée de lingots,coulée continue, …) peuvent générer des défauts : macro-ségrégation, mauvaises propriétés de la microstructure, défauts surfaciques. Ces problèmes peuvent être résolus par un contrôle de la température et de l’écoulement d'acier liquide. Le brassage électromagnétique (EMS) est une technique largement utilisée pour contrôler l’écoulement d'acier liquide par l’imposition d'un champ électromagnétique. Cette technique est complexe car elle couple plusieurs types de problèmes physiques:écoulement multiphasique, solidification,transfert de chaleur et induction électromagnétique à basse fréquence.En outre, l’approche expérimentale est difficile de par la dimension,l'environnement et le coût des procédés considérés. Pour ces raisons, des simulations numériques efficaces sont nécessaires pour comprendre les applications EMS et améliorer les procédés évoqués. L'objectif de cette thèse est de développer une méthodologie numérique robuste,efficace et précise pour la simulation multi-physique de l'EMS, en particulier pour le brassage dans le moule dans le cadre de la coulée continue d'acier. Cette méthodologie a été mise en oeuvre dans le code commercial THERCAST® pour être utilisé dans le cadre d’applications industrielles<br>Many of the processes used in thesteelmaking industry (e.g. ingot casting,continuous casting, …) can lead todefects: macro-segregation, poormicrostructure properties, surfacedefects. These issues can be solved bycontrolling the temperature and the flowof molten steel. Electromagnetic stirring(EMS) is a widely used technique to steerthe flow of liquid steel by thesuperimposition of an electro-magneticfield. This application is complex becauseit couples several physical problems:multi-phase flow, solidification, heattransfer and low frequency electromagneticinduction. In addition,experimental work is difficult because ofthe size, environment and cost of theconsidered processes. For thesereasons, efficient and effective numericalsimulations are needed to understandEMS applications and improve theaforementioned processes.The objective of this thesis is to developa robust, efficient and accurate numericalprocedure for the multi-physicssimulation of EMS, especially for in-moldstirring in the framework of continuouscasting of steel. This procedure has beenimplemented in the commercial codeTHERCAST® in order to be used forindustrial applications

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Nandy, Arup Kumar. "Robust Finite Element Strategies for Structures, Acoustics, Electromagnetics and Magneto-hydrodynamics." Thesis, 2016. http://hdl.handle.net/2005/2913.

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The finite element method (FEM) is a widely-used numerical tool in the fields of structural dynamics, acoustics and electromagnetics. In this work, our goal is to develop robust FEM strategies for solving problems in the areas of acoustics, structures and electromagnetics, and then extend these strategies to solve multi-physics problems such as magnetohydrodynamics and structural acoustics. We now briefly describe the finite element strategies developed in each of the above domains. In the structural domain, we show that the trapezoidal rule, which is a special case of the Newmark family of algorithms, conserves linear and angular momenta and energy in the case of undamped linear elastodynamics problems, and an ‘energy-like measure’ in the case of undamped acoustic problems. These conservation properties, thus, provide a rational basis for using this algorithm. In linear elastodynamics variants of the trapezoidal rule that incorporate ‘high-frequency’ dissipation are often used, since the higher frequencies, which are not approximated properly by the standard displacement-based approach, often result in unphysical behavior. Instead of modifying the trapezoidal algorithm, we propose using a hybrid FEM framework for constructing the stiffness matrix. Hybrid finite elements, which are based on a two-field variational formulation involving displacement and stresses, are known to approximate the eigenvalues much more accurately than the standard displacement-based approach, thereby either bypassing or reducing the need for high-frequency dissipation. We show this by means of several examples, where we compare the numerical solutions obtained using the displacementbased and hybrid approaches against analytical solutions. We also present a monolithic formulation for the solution of structural acoustic problems based on the hybrid finite element approach. In the area of electromagnetics, since our goal is to ultimately couple the electromagnetic analysis with structural or fluid variables in a ‘monolithic’ framework, we focus on developing nodal finite elements rather than using ‘edge elements’. It is well-known that conventional nodal finite elements can give rise to spurious solutions, and that they cannot capture singularities when the domains are nonconvex and have sharp corners. The commonly used remedies of either adding a penalty term or using a potential formulation are unable to address these problems satisfactorily. In order to overcome this problem, we first develop several mixed finite elements in two and three dimensions which predict the eigenfrequencies (including their multiplicities) accurately, even for non-convex domains. In this proposed formulation, no ad-hoc terms are added as in the penalty formulation, and the improvement is achieved purely by an appropriate choice of the finite element spaces for the different variables. For inhomogeneous domains, ‘double noding’ is used to enforce the appropriate continuity conditions at an interface. Although the developed mixed FEM works very accurately for all 2D geometries and regular Cartesian 3D geometries, it has so far not yielded success for curved 3D geometries. Therefore, for 3D harmonic and transient analysis problems, we propose and use a modified form of the potential formulation that overcomes the disadvantages of the standard potential method, especially on non-convex domains. Electromagnetic radiation and scattering in an exterior domain traditionally involved imposing a suitable absorbing boundary condition (ABC) on the truncation boundary of the numerical domain to inhibit reflection from it. In this work, based on the Wilcox asymptotic expansion of the electric far-field, we propose an amplitude formulation within the framework of the nodal FEM, whereby the highly oscillatory radial part of the field is separated out a-priori so that the standard Lagrange interpolation functions have to capture a relatively gently varying function. Since these elements can be used in the immediate vicinity of the radiator or scatterer (with few exceptions which we enumerate), it is more effective compared to methods of imposing ABCs, especially for high-frequency problems. We show the effectiveness of the proposed formulation on a wide variety of radiation and scattering problems involving both conducting and dielectric bodies, and involving both convex and non-convex domains with sharp corners. The Time Domain Finite Element Method (TDFEM) has been used extensively to solve transient electromagnetic radiation and scattering problems. Although conservation of energy in electromagnetics is well-known, we show in this work that there are additional quantities that are also conserved in the absence of loading. We then show that the developed time-stepping strategy (which is closely related to the trapezoidal rule) mimics these continuum conservation properties either exactly or to a very good approximation. Thus, the developed numerical strategy can be said to be ‘unconditionally stable’ (from an energy perspective) allowing the use of arbitrarily large time-steps. We demonstrate the high accuracy and robustness of the developed method for solving both interior and exterior domain radiation problems, and for finding the scattered field from conducting and dielectric bodies. In the field of magneto-hydrodynamics, we develop a monolithic strategy based on a continuous velocity-pressure formulation that is known to satisfy the Babuska-Brezzi (BB) conditions. The magnetic field is interpolated in the same way as the velocity field, and the entire formulation is within a nodal finite element framework. Both transient and steady-state formulations are developed for two- and three-dimensional geometries. An exact linearization of the monolithic strategy ensures that rapid (quadratic) convergence is achieved within each time (or load) step, while the stable nature of the interpolations used ensure that no instabilities arise in the solution. Good agreement with analytical solutions, even with the use of very coarse meshes, shows the efficacy of the developed formulation.

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Books on the topic "Hydrodynamic formulation"

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Succi, Sauro. Generalized Hydrodynamics Beyond Navier–Stokes. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780199592357.003.0006.

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The work of Chapman and Enskog opened a long period, lasting about three decades, in which most of the activity in kinetic theory was directed to the computation of the transport coefficients for different types of intermolecular potentials. Seeking the solution of the full Boltzmann equation itself was not much in focus, mostly on account of its daunting complexity. This situation took a sharp turn in 1949, with the publication of Harold Grad’s thesis. This Chapter presents the derivation of generalized hydrodynamics beyond the realm of the Navier-Stokes description, with special reference to Grad’s thirteen-moment formulation.

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R, Ohayon, and United States. National Aeronautics and Space Administration., eds. Mixed variational formulations of finite element analysis of elastoacoustic/slosh fluid structure interaction. National Aeronautics and Space Administration, 1991.

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Succi, Sauro. Lattice Gas-Cellular Automata. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780199592357.003.0011.

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This chapter discusses the ancestor of the Lattice Boltzmann, the Boolean formulation of hydrodynamics known as lattice Gas Cellular Automata. In 1986, Uriel Frisch, Brosl Hasslacher and Yves Pomeau sent big waves across the fluid dynamics community: a simple cellular automaton obeying nothing but conservation laws at a microscopic level was able to reproduce the complexity of real fluid flows. This discovery spurred great excitement in the fluid dynamics community. The prospects were tantalizing: around free, intrinsically parallel computational paradigm for fluid flows. However, a few serious problems were quickly recognized and addressed with great intensity in the following years.

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Jones, Julie Ellis, and Hashim Hashim. Urodynamics. Edited by Christopher R. Chapple. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780199659579.003.0035.

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Urodynamic studies encompass several tests to investigate the hydrodynamics of the lower urinary tract during bladder storage/filling and voiding. These tests include bladder diaries, free uroflowmetry, and post-void residuals, filling cystometry, voiding pressure/flow studies, urethral pressure profiles, leak point pressures, videourodynamics, ambulatory urodynamics, and electromyography. The tests are performed after formulating a urodynamics question to objectively observe lower urinary tract function and dysfunction with the idea of choosing an appropriate treatment for the pathology. Invasive urodynamic tests require appropriate training, as per the joint statement on minimum standards for urodynamic practice in the United Kingdom, and should be performed according to the International Continence Society good urodynamics practice guidelines. It is also important to be able to interpret the traces appropriately and troubleshoot any problems occurring during the test.

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Book chapters on the topic "Hydrodynamic formulation"

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Bruner de Miranda, Luiz, Fernando Pinheiro Andutta, Björn Kjerfve, and Belmiro Mendes de Castro Filho. "Hydrodynamic Formulation: Mass and Salt Conservation Equations." In Fundamentals of Estuarine Physical Oceanography. Springer Singapore, 2017. http://dx.doi.org/10.1007/978-981-10-3041-3_7.

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Bruner de Miranda, Luiz, Fernando Pinheiro Andutta, Björn Kjerfve, and Belmiro Mendes de Castro Filho. "Hydrodynamic Formulation: Equations of Motion and Applications." In Fundamentals of Estuarine Physical Oceanography. Springer Singapore, 2017. http://dx.doi.org/10.1007/978-981-10-3041-3_8.

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Ungarish, Marius. "Physico-Mathematical Formulation." In Hydrodynamics of Suspensions. Springer Berlin Heidelberg, 1993. http://dx.doi.org/10.1007/978-3-662-01651-0_2.

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Hermans, A. J. "Asymptotic Formulation." In Water Waves and Ship Hydrodynamics. Springer Netherlands, 2011. http://dx.doi.org/10.1007/978-94-007-0096-3_5.

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Hermans, A. J. "Boundary Integral Formulation and Ship Motions." In Water Waves and Ship Hydrodynamics. Springer Netherlands, 2011. http://dx.doi.org/10.1007/978-94-007-0096-3_3.

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Wijesinghe, Hettithanthrige S., and Nicolas G. Hadjiconstantinou. "Hybrid Atomistic-Continuum Formulations for Multiscale Hydrodynamics." In Handbook of Materials Modeling. Springer Netherlands, 2005. http://dx.doi.org/10.1007/978-1-4020-3286-8_133.

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Wijesinghe, Hettithanthrige S., and Nicolas G. Hadjiconstantinou. "Hybrid Atomistic-Continuum Formulations for Multiscale Hydrodynamics." In Handbook of Materials Modeling. Springer Netherlands, 2005. http://dx.doi.org/10.1007/1-4020-3286-2_133.

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Peitz, Jochen, and Stefan Appl. "Relativistic Dissipative Hydrodynamics in the 3+1 Formulation." In Hyperbolic Problems: Theory, Numerics, Applications. Birkhäuser Basel, 1999. http://dx.doi.org/10.1007/978-3-0348-8724-3_28.

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Smith, Arlynn W., and Kevin F. Brennan. "Comparison of Hydrodynamic Formulations for Non-Parabolic Semiconductor Device Simulations." In Simulation of Semiconductor Devices and Processes. Springer Vienna, 1995. http://dx.doi.org/10.1007/978-3-7091-6619-2_66.

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Utsumi, Takayuki. "Differential algebraic hydrodynamics solver with cubic-polynomial interpolation — two dimensional formulation —." In Computational Mechanics ’95. Springer Berlin Heidelberg, 1995. http://dx.doi.org/10.1007/978-3-642-79654-8_169.

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Conference papers on the topic "Hydrodynamic formulation"

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Ghannam, Mahmoud Yousef. "Mathematical Formulation for Hydrodynamic Stability of Fluidic Jets." In SAE 2002 World Congress & Exhibition. SAE International, 2002. http://dx.doi.org/10.4271/2002-01-0216.

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Aquelet, N., and M. Souli. "Explicit Coupling Methods in Hydrodynamic Impacts." In ASME 2005 Pressure Vessels and Piping Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/pvp2005-71656.

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The purpose of this paper is to study and compare two finite element coupling methods to simulate the problem of a body penetrating a free surface. The hydrodynamic impact problem concerns industrial designers in shipbuilding domain. In rough seas, sometimes ships suffer local damages from large water impact loads called slamming impacts. In the framework of a collaboration with a french research company in shipbuilding (Principia Marine) a numerical prediction of the local impulse load on a wedge striking a free surface is investigated by using two methods: penalty and Lagrange multiplier formulations. These methods of coupling, which makes it possible to transmit the efforts in pressure from the Eulerian formulation to the Lagrangian formulation and conversely are relatively recent algorithmic developments. The Euler/Lagrange penalty method was successfully used in many scientific and industrial applications: the modeling of the attack of birds on the fuselage of a Jet for the Boeing Corporation, the underwater explosion shaking the oil platforms, the airbag simulation... The explicit coupling based on multiplier approach is a new development, which is compared to the penalty method. For both methods, a parametric study of the local pressure peak is investigated for impact angles from 0 to 30 degrees.

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AlHasni, Hani, Ona Thornquist, Shafquat Islam, Peter Garrison, and Iskender Sahin. "Hydrodynamic Coefficients for an Extraterrestrial Submarine." In ASME 2019 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/imece2019-10257.

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Abstract An autonomous submarine design was proposed as part of NASA’s NIAC program to explore the hydrocarbon seas of Titan, the Saturnian moon, and study its hydrological cycle. The submarine is to be capable of operating at both the surface and in a deeply-submerged mode. This study aims to complement and compare previous CFD simulations with results obtained using the panel code CMARC. The comparison is of interest as the previous studies included a grid-based viscous code and a particle method using smoothed-particle hydrodynamics. The previous approaches encountered difficulties in obtaining agreeable results as each method has flow regimes suitable for a specific formulation, specifically free-surface flow versus a deeply submerged case. The panel formulation presented here is for the deeply submerged configuration and results match well with other approaches and parametric analyses, particularly when appendages are included in the modeling.

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Daghigh, M. "A New Formulation for Equivalent Hydrodynamic Modeling of the Jack-Up Legs." In ASME 2002 21st International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2002. http://dx.doi.org/10.1115/omae2002-28342.

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Regulations of offshore structures suggest the application of Morison type equation for the estimation of forces induced by wave and current on the slender bodies of Jacket and Jack-up structures. However, common values of hydrodynamic coefficients are rarely defined in two different regulations. Estimation of global responses of Jack-up structure, the simplified geometrical model is used, therefore we will try to modify the DNV formulations in order to estimate the hydrodynamic forces on equivalent pile. Finally, the forces on the real structure and the equivalent pile model are compared and it has been shown that the approximation of the inertia forces has more accuracy comparing to the drag force, due to the nonlinear effect in drag term.

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Ledru, Rémi, Cédric Le Cunff, Jean-Michel Heurtier, Timothée Perdrizet, and Yann Poirette. "Influence of Hydrodynamic Modeling Assumptions on Floating Wind Turbine Behaviour." In ASME 2014 33rd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/omae2014-24396.

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This paper aims to highlight the key physical aspects that govern the dynamic behavior of a trifloater based floating wind turbine and the modeling assumptions — with a focus on hydrodynamics modeling and platform/tower interface flexibility — required to properly take into account the coupled hydrodynamics and aerodynamics effects in the fatigue analysis. Three selected load cases are simulated with different hydrodynamics models and the results are compared to each other. On this specific floating structure, Morison formulation seems to provide very similar results compared to other hydrodynamic modeling approaches based on potential flow theory and a more consistent way to model the floater damping. The use of a hybrid formulation including Morison damping on the columns instead of a quadratic damping matrix is an interesting alternative since it gathers the advantages of the different models.

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SZYMCZAK, W., J. SOLOMON, A. BERGER, and J. ROGERS. "A numerical method based on a generalized formulation of hydrodynamic free surface problems." In 10th Computational Fluid Dynamics Conference. American Institute of Aeronautics and Astronautics, 1991. http://dx.doi.org/10.2514/6.1991-1541.

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Yasko, Isaiah, Anbara Lutfullaeva, Collier Fais, Muhammad Ali, and Khairul Alam. "Thermal Expansion Simulation of Composite Hydrodynamic Thrust Bearings." In ASME 2020 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/imece2020-23898.

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Abstract Fixed-geometry hydrodynamic thrust bearings rely on convergent geometry on the bearing face in the direction of relative motion to develop and maintain hydrodynamic pressure. Machining the convergent taper feature onto the bearing using traditional manufacturing processes can prove to be a difficult process due to the small magnitude of taper depth necessary for proper bearing performance. The work presented here investigates three different types of carbon fibers (AS-4/IM7/T-300) in an epoxy (3501-6) matrix for composite lamina formulation in taper-land composite thrust bearings as a means of controlling taper depth via thermal expansion so that favorable bearing functionality is maintained during load fluctuation without the need for traditional machining processes to create the taper. Thermal expansion of specific composite laminate formulation is analyzed using the ABAQUS/CAE composite module. The thermo-mechanical analysis shows that under realistic in-service temperature conditions resulting from bearing friction-torque, the thermal expansion of composite tapered-land thrust bearings expand to provide physical surface gradient magnitudes of 0.09504 mm, 0.08987 mm and 0.08829 mm that are capable of producing hydrodynamic pressure.

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Hoekstra, Carel, Henk Smienk, Joris van Drunen, and Alessio Pistidda. "Applying CFD for In-Line Structure Hydrodynamics in Pipeline Installation Analysis." In ASME 2016 35th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/omae2016-54273.

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Over the last decade Heerema Marine Contractors (HMC) has successfully performed multiple installation campaigns of large sized in-line structures (ILS) with Deep Water Construction Vessels (DCV) Aegir and Balder. Nowadays steady increase in size and weight of ILS have made these special operations even more complex. Presence of large sized ILS and accompanying buoyancy modules in the catenary have proven to play a dominant role in pipeline integrity. Originally hydrodynamic force formulations in finite element analysis are solely designated for the pipeline itself. These computations comprehend the application of the Morison equation using constant hydrodynamic coefficients of basic shapes in steady flow. Therefore hydrodynamic forces acting on the ILS, characterized by irregular relative motions of a complex shaped and perforated structure, are highly simplified while playing a dominant role in the analyses. Validity of applying the standard Morison equation is debatable, since large ILS cannot be assumed slender. Nonetheless Morison type formulations can provide reasonable results depending on the accuracy of the hydrodynamic coefficients. Deriving these coefficients for complex shaped structures using industry standards is a highly interpretive process involving an accumulation of assumptions. This approach yields varying coefficients, which are applied conservatively in installation analyses, resulting in an unnecessary reduction of DCV offshore workability. To improve workability of these complex installations, HMC has implemented an ILS specific hydrodynamic profile from Computational Fluid Dynamics (CFD) analysis into the installation analyses. This is effectuated by the development of an enhanced methodology with a dedicated hydrodynamic formulation for large perforated ILS. Dependencies on Keulegan-Carpenter (KC) number and local angle of attack are addressed in this formulation to respectively cover the inertia dominated oscillating motions and complex geometric composition. The applied hydrodynamic formulation is based on work of Molin et al. which showed a good agreement to the CFD analysis performed for this study. Development and application of this methodology is initiated as a first assessment towards more accurate ILS installation analyses. Analysis of a study case shows reductions up to 50% of maximum bending strain in a specific regular wave analysis. From the work presented it is concluded that the industry practice vastly overestimates hydrodynamic forcing on large sized ILS. Complementary research is needed on the topics of oscillations for low (<1.0) KC number, effects of relative fluid velocity and finally the implementation of irregular waves.

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Tourbier, Matthieu, Bernard Peseux, Bundi Donguy, and Laurent Gornet. "Modelling and Simulation of the Three-Dimensional Hydrodynamic Problem." In ASME 2002 Pressure Vessels and Piping Conference. ASMEDC, 2002. http://dx.doi.org/10.1115/pvp2002-1142.

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This paper deals with slamming phenomenon (impact between bow ship and water free surface). Slamming loads on ship may be sufficiently important so as to create plastic deformations of the hull external structure. In extreme cases, they have been recognised for being responsible for the loss of ships. The problem to solve is transient and highly non-linear due to the character of the flow. In the present paper, the three-dimensional Wagner problem is solved numerically using a variational formulation together with a Finite Element Method. Three-dimensional results for simple rigid bodies such as a cone and an ellipsoid are successfully compared with analytical results. Results for deformable structure will be presented.

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Ahmed, Aziz, M. Abdullah Al Maruf, Arun Kr Dev, and Mohammed Abdul Hannan. "Preliminary Analytical Formulation of Ice-Floater Interactions Including the Effect of Wave Load." In ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/omae2018-78340.

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Diminishing ice presence in the Arctic provides the potential for extended operable period for oil and gas exploration in the Arctic. Floaters are a flexible solution for such scenario whereas they can fully take advantage of the extended drilling season as well as operate in other harsh environment regions during the off-season. Such floaters can disconnect and reconnect to avoid large ice features such as icebergs and multi-year ice ridges. However, they still need to encounter relatively large level ice. Accompanying icebreakers will ideally assist in breaking the level ice into manageable pieces. The interaction of such level ice floes with floater has a significant influence on the dynamic ice load on the floater and resulting mooring load. There is significant uncertainty in the simulation of level ice-floater interaction numerically. Most of the current research focuses on the influence of ice breaking and subsequent flow of the broken ice around the floater. However, the hydrodynamic load due to the incoming level ice will also affect the response of the floater, which is usually not simulated. A recent study simulated the multibody hydrodynamics of level ice and floater Such multibody hydrodynamic analysis is computationally expensive, and complexity in the modelling is a hindrance to its implementation in the design phase. The present study, therefore, employs a conservative estimation to include the effect of wave load on the floater in addition to the ice load. Parametric studies are performed to estimate this effect by varying the incoming wave amplitude and wave period, ice sheet thickness, ice drift velocity, floater’s hull angle, mooring stiffness and the distance of large ice-sheet from the floater. Significant impacts of waves on the floater in terms of total force are observed which clearly reflects the importance of this study. The effect of mooring stiffness on total load is also investigated at the end of this study which can be considered as a foundation for further research on optimizing the mooring stiffness for such kind of arctic floater.

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Reports on the topic "Hydrodynamic formulation"

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Riveros, Guillermo, Felipe Acosta, Reena Patel, and Wayne Hodo. Computational mechanics of the paddlefish rostrum. Engineer Research and Development Center (U.S.), 2021. http://dx.doi.org/10.21079/11681/41860.

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Purpose – The rostrum of a paddlefish provides hydrodynamic stability during feeding process in addition to detect the food using receptors that are randomly distributed in the rostrum. The exterior tissue of the rostrum covers the cartilage that surrounds the bones forming interlocking star shaped bones. Design/methodology/approach – The aim of this work is to assess the mechanical behavior of four finite element models varying the type of formulation as follows: linear-reduced integration, linear-full integration, quadratic-reduced integration and quadratic-full integration. Also presented is the load transfer mechanisms of the bone structure of the rostrum. Findings – Conclusions are based on comparison among the four models. There is no significant difference between integration orders for similar type of elements. Quadratic-reduced integration formulation resulted in lower structural stiffness compared with linear formulation as seen by higher displacements and stresses than using linearly formulated elements. It is concluded that second-order elements with reduced integration and can model accurately stress concentrations and distributions without over stiffening their general response. Originality/value – The use of advanced computational mechanics techniques to analyze the complex geometry and components of the paddlefish rostrum provides a viable avenue to gain fundamental understanding of the proper finite element formulation needed to successfully obtain the system behavior and hot spot locations.

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