SPH Numerical Simulations of the Deformation of a Liquid Surface in Two Dimensions

2019 ◽  
pp. 63-75
Author(s):  
Cristian Cáliz-Reyes ◽  
Laura A. Ibarra-Bracamontes ◽  
Rosanna Bonasia ◽  
Gonzalo Viramontes-Gamboa
Keyword(s):  
Numerical Simulations ◽  
Liquid Surface ◽  
Two Dimensions

Direct numerical simulations of Rayleigh–Bénard convection in water with non-Oberbeck–Boussinesq effects

2019 ◽  
Vol 881 ◽  
pp. 1073-1096 ◽  
Author(s):  
Andreas D. Demou ◽  
Dimokratis G. E. Grigoriadis
Keyword(s):  
Numerical Simulations ◽  
Two Dimensions ◽  
Direct Numerical Simulations ◽  
Wall Region ◽  
Number Range ◽  
Bénard Convection ◽  
Benard Convection ◽  
Rayleigh Benard Convection ◽  
Rayleigh Benard ◽  
Near Wall

Rayleigh–Bénard convection in water is studied by means of direct numerical simulations, taking into account the variation of properties. The simulations considered a three-dimensional (3-D) cavity with a square cross-section and its two-dimensional (2-D) equivalent, covering a Rayleigh number range of $10^{6}\leqslant Ra\leqslant 10^{9}$ and using temperature differences up to 60 K. The main objectives of this study are (i) to investigate and report differences obtained by 2-D and 3-D simulations and (ii) to provide a first appreciation of the non-Oberbeck–Boussinesq (NOB) effects on the near-wall time-averaged and root-mean-squared (r.m.s.) temperature fields. The Nusselt number and the thermal boundary layer thickness exhibit the most pronounced differences when calculated in two dimensions and three dimensions, even though the $Ra$ scaling exponents are similar. These differences are closely related to the modification of the large-scale circulation pattern and become less pronounced when the NOB values are normalised with the respective Oberbeck–Boussinesq (OB) values. It is also demonstrated that NOB effects modify the near-wall temperature statistics, promoting the breaking of the top–bottom symmetry which characterises the OB approximation. The most prominent NOB effect in the near-wall region is the modification of the maximum r.m.s. values of temperature, which are found to increase at the top and decrease at the bottom of the cavity.

scholarly journals Seismic stimulation for enhanced oil recovery

Geophysics ◽  
2008 ◽  
Vol 73 (5) ◽  
pp. O23-O35 ◽  
Author(s):  
Steven R. Pride ◽  
Eirik G. Flekkøy ◽  
Olav Aursjø
Keyword(s):  
Pressure Gradient ◽  
Numerical Simulations ◽  
Oil Recovery ◽  
Scale Effects ◽  
Fluid Pressure ◽  
Oil Production ◽  
Two Dimensions ◽  
Lattice Boltzmann Model ◽  
Pore Scale ◽  
Capillary Barriers

The pore-scale effects of seismic stimulation on two-phase flow are modeled numerically in random 2D grain-pack geometries. Seismic stimulation aims to enhance oil production by sending seismic waves across a reservoir to liberate immobile patches of oil. For seismic amplitudes above a well-defined (analytically expressed) dimensionless criterion, the force perturbation associated with the waves indeed can liberate oil trapped on capillary barriers and get it flowing again under the background pressure gradient. Subsequent coalescence of the freed oil droplets acts to enhance oil movement further because longer bubbles overcome capillary barriers more efficiently than shorter bubbles do. Poroelasticity theory defines the effective force that a seismic wave adds to the background fluid-pressure gradient. The lattice-Boltzmann model in two dimensions is used to perform pore-scale numerical simulations. Dimensionless numbers (groups of material and force parameters) involved in seismic stimulation were defined carefully so that numerical simulations could be applied to field-scale conditions. Using defined analytical criteria, there is a significant range of reservoir conditions over which seismic stimulation can be expected to enhance oil production.

scholarly journals Crystal Growth and the Formation of Spikes in the Surface of Supercooled Water

1960 ◽  
Vol 3 (28) ◽  
pp. 698-704 ◽  
Author(s):  
J. Hallett
Keyword(s):  
Crystal Growth ◽  
Single Crystal ◽  
Composite Structure ◽  
Liquid Surface ◽  
Supercooled Water ◽  
Two Dimensions ◽  
Optic Axis ◽  
Ice Crystals ◽  
Precise Form ◽  
Initial Nucleus

Abstract Observations made of ice crystals growing on the surface of supercooled water show that they take the form of a composite structure, called surface needles, each of which consists of dendrites growing into the liquid, and of ribs growing in the liquid surface. Each needle is a single crystal. The precise form of the needle is determined by the orientation of the initial nucleus. If its optic axis is near normal to the surface, growth occurs rapidly in two dimensions and covers a much larger proportion of the surface than is covered by the narrow surface needles, so that ice forming this way appears to have its optic axis vertical. Hollow ice spikes observed on pools are shown to have been formed by the freezing of water forced from beneath the surface at the intersection of two or three surface needles, the shape of the spike depending on their orientation.

SCALING BEHAVIOUR OF A MULTIPLY CONNECTED FLUCTUATING INTERFACE IN TWO DIMENSIONS

Fractals ◽  
2003 ◽  
Vol 11 (supp01) ◽  
pp. 227-232
Author(s):  
AYŞE ERZAN ◽  
HÜSEY.IN KAYA ◽  
ALKAN KABAKÇIOĞLU
Keyword(s):  
Kinetic Model ◽  
Numerical Simulations ◽  
Average Velocity ◽  
Two Dimensions ◽  
Scaling Exponents ◽  
Multiply Connected ◽  
Fractal Set ◽  
Scaling Behaviour ◽  
Infinite String

We consider a one-parameter kinetic model for a fluctuating interface which can be thought of as an infinite string decorated with infinitely many closed strings. Numerical simulations show that a number of scaling exponents describing this string system may be related to the Kardar-Parisi-Zhang exponents. However, as the average velocity of the infinite string is taken to zero, and the string system becomes an isotropic fractal set, we also find new exponents which cannot be reduced to previously known ones.

A Voronoi Cell Material Point Method for Large Deformation Solid Mechanics Problems

2016 ◽  
Vol 846 ◽  
pp. 108-113
Author(s):  
Vinh Phu Nguyen ◽  
Giang Dinh Nguyen
Keyword(s):  
Numerical Simulations ◽  
Solid Mechanics ◽  
Impact Damage ◽  
Voronoi Cell ◽  
Material Point ◽  
Two Dimensions ◽  
Point Method ◽  
Particle Methods ◽  
Contact Impact ◽  
Polygonal Particle

Particle methods have been increasingly used in numerical simulations of complex problemsin both sciences and engineering. A plethora of different particle methods exists of which thematerial point method (MPM) is a promising method that is able to deal with high strain rate problemsthat involve contact, impact, damage and fragmentation. Particle domains in the MPM are currentlyrepresented by quadrilaterals in two dimensions. Extension to polygonal particle domains is presentedbased on a simple sub-division of the polygons into sub-triangles. This allows MPM simulations tobe carried out for structures and materials discretized by Voronoi tessellations. Performances of theproposed method are illustrated by means of numerical simulations.

A Study of Cavitation Bubble Temperatures in Room Temperature Ionic Liqiud

2013 ◽  
Vol 718-720 ◽  
pp. 209-213
Author(s):  
Yue Tao Yang ◽  
Bin Gao ◽  
Xiao Jun Liu ◽  
Shu Yi Zhang
Keyword(s):  
Numerical Simulations ◽  
Cavitation Bubble ◽  
Room Temperature ◽  
Bubble Dynamics ◽  
Liquid Surface ◽  
Methyl Radical ◽  
Bubble Dynamic ◽  
Point Of Interest ◽  
Liquid Surface Tension ◽  
The Difference

Room temperature ionic liquids (RTIL) have been developed to a central point of interest in both academia and industry. RTIL is non-volatile, thermally stable and non-flammable solvent. These properties can offer a green opportunity for sonochemical reactions. In this work, the cavitation bubble temperatures have been measured using methyl radical recombination (MRR) method. The temperatures measured in ImPF6 are in the range of 3000 4000 K. Additionally, based on the bubble dynamic equation with the consideration of liquid surface tension, viscosity and radiative resistance, numerical simulations have been carried out to investigate the cavitation bubble dynamics. The difference of the temperatures obtained from the experiment and numerical simulations has been interpreted.

Two-Dimensional Linear Friction Damper Consisting of Concave Cone and Cylindrical Member (Investigation of Performance by Numerical Simulation and Experiment)

2015 ◽  
Author(s):  
Hideya Yamaguchi ◽  
Hidehisa Yoshida
Keyword(s):  
Numerical Simulations ◽  
Friction Force ◽  
Vibration Isolation ◽  
Two Dimensions ◽  
Resonant Peak ◽  
Friction Damper ◽  
Isolation System ◽  
Friction Forces ◽  
Vibration Isolation System ◽  
Linear Friction

A passive vibration isolation system consisting of a constant friction force has performance limitations; the isolation performance declines and the residual displacement becomes large in the case of the large friction force, while the resonant peak becomes large in the case of the small friction force. It is known that above drawbacks are avoidable when the friction force varies in proportion to the relative displacement. Recently, authors have proposed a simple linear friction damper mechanism that consists of a cylindrical block and a tilt lever supported with a pivot or a leaf spring. Performance of the vibration isolation system equipped with the proposed damper is investigated, and its effectiveness is confirmed by numerical simulations and the experiments. However, the motion of the mechanism is limited to one-dimension. This paper proposes an extended mechanism that can be applied to motion moving in two dimensions by combining the concave cone and the cylindrical member. The concave cone is supported with a universal joint on the apex side and its tilting motion is constrained by the restoring spring. The rounded edge of the cylindrical member is set up to contact the inside flank of the concave cone. When the cylindrical member moves in an arbitrary direction on the planar floor and pushes the concave cone, the normal and friction forces at the contact point vary depending on the displacement of the cylindrical member. The fundamental property and the performance of the proposed mechanism are investigated by numerical simulations and experiments.

Replicating Spots in Reaction-Diffusion Systems

1997 ◽  
Vol 07 (05) ◽  
pp. 1149-1158 ◽  
Author(s):  
Kyoung J. Lee ◽  
Harry L. Swinney
Keyword(s):  
Cell Division ◽  
Numerical Simulations ◽  
Continuous Process ◽  
Reaction Diffusion ◽  
Two Dimensions ◽  
Diffusion System ◽  
One Dimension ◽  
Reaction Diffusion Systems ◽  
Gel Layer ◽  
Diffusion Systems

We review the phenomenon of replicating spots in reaction-diffusion systems and discuss the mechanism of replication. This phenomenon was discovered in recent experiments on a ferrocyanide-iodate-sulfite reaction-diffusion system. Patterns form in a thin gel layer that is in contact with a continuously fed stirred reservoir. Patterns of spots are observed to undergo a continuous process of growth and multiplication through cell division and death through overcrowding. A similar phenomenon is also found in numerical simulations in one dimension on a four-species model of the ferrocyanide-iodate-sulfite reaction and in simulations in two dimensions of simpler two-species reaction-diffusion models: Gray–Scott model by J. Pearson and FitzHugh–Nagumo model by A. Hagberg and E. Meron.

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