Force Scheme Research Articles

СРАВНИТЕЛЬНЫЙ АНАЛИЗ СИЛ СОПРОТИВЛЕНИЯ КОПАНИЮ, ДЕЙСТВУЮЩИХ НА СЕРИЙНЫЙ КОВШ ЭКСКАВАТОРА И КОВШ ЦИЛИНДРИЧЕСКОЙ ФОРМЫ

The purpose of the work consists in the productivity increase of a single-bucket excavator at the expense of bucket shape perfection. The improved and offered bucket design will allow scooping more soil without changing hydraulic drive characteristics. This effect is achieved at the expense of the cylindrical shape of the rear wall of the bucket. There is presented a computation scheme of forces acting upon an improved bucket. The calculations of the advanced excavator bucket based on the YuMZ-6AKL tractor allowed drawing an outline of the supposed design and obtaining moment dependences of resistance on a bucket during digging upon a bucket rotation angle. The dependences of moment resistance on the bucket are formed for buckets with the capacity of 0.25m3, 0.35m3, 0.45m3, 0.55m3 and 0.65m3. The improved bucket design will allow increasing the volume of soil scooped thereby increasing productivity of single-bucket hydraulic excavators. Investigation methods – theoretical researches. The investigation results and novelty: there is offered the improved design of a bucket, a calculation circuit of forces acting upon an improved bucket. Conclusions: the advanced design of a bucket will allow scooping a larger volume of soil without changing hydraulic drive characteristics. In such a way, the productivity increase of single-bucket hydraulic excavators without changing hydraulic drive characteristic is achieved.

SOIL LAYER CUT OFF BY THE AGGREGATE FOR REMOVING THE TOPSOIL FROM THE ROAD SUBLAYER: DETERMINATION OF THE CHAIN SPEED AND SIZES

Introduction.For the durable road at the minimum necessary cost of its construction the topsoil should be removed without affecting the ground. The problem of cheaper road construction without reducing the quality can be solved by creating an aggregate for the sublayer’s formation. The aggregate removes the topsoil from half of the road sublayer and one of the ditch. The buckets of the moving aggregate cut off the soil layer from below and from one side. Therefore, each bucket is mounted by the bottom blade, the right blade and the console blade, partially cutting the topsoil from below for the passage of the next bucket. The blade of the lower knife with the 10 degrees’ angle to the plank of the bucket; the blade of the right knife and the blade of the console knife – with the 45 degrees’ angle towards the direction of the bucket moving.Materials and methods. To determine the speed of chains and the size of the soil layer the author carried out the bucket kinematics’ analysis and considered mathematical transformations. For checking the received parameters, the paper demonstrated the turn of the bucket on the leading 90 degrees’ lower drive. The author revealed the scheme of forces acting on the ground, located in the bucket, when it turned on the leading lower drive. Based on the system’s transformations of two equations and the inequality, the research established the inadmissibility of the bucket’s phasing out when it turned on the leading lower drive.Results. As a result, by using the developed method of determining parameters, based on the accepted raw data, the author calculated the speed of the chains, to which the buckets were attached, and the width of the soil, cut off by the bucket. After substitution of the received parameters in the inequality the author established that the ground would not fall out of the bucket by turning under such parameters of the bucket and of the leading lower drive.Discussion and conclusions.As a result, the author obtains the geometric parameters from the structural layout of the aggregate for removing the topsoil from the road sublayer. Based on the analysis of the kinematics of the interaction of the bucket with the ground, the paper reveals the speed of the chains, to which the buckets are attached and the width of the soil layer cut off by the bucket. Analysis of the forces acting on the ground and locating in the bucket at the moment of the bucket turn on the leading lower drive shows the rationality of the accepted and calculated parameters. The author determines the energy costs of cutting the ground with the buckets of the aggregate for removing the topsoil from the road sublayer.Financial transparency: the author has no financial interest in the presented materials or methods. There is no conflict of interest.

On the secrecy performance of integrated satellite‐aerial‐terrestrial networks

SummaryThis paper investigates secure transmission of an integrated satellite‐aerial‐terrestrial network (ISATN), where multiple eavesdroppers (Eves) attempt to overhear the satellite signals cooperatively. The ISATN adopts an unmanned aerial vehicle (UAV) equipped with multiple antennas as a relay with threshold‐based decode‐and‐forward (DF) protocol. By assuming that perfect instantaneous channel state information (CSI) of the satellite‐UAV link and the statistical CSI of the UAV‐user link are available, we first propose a beamforming (BF) scheme for maximizing the achievable secrecy rate (ASR) of the considered network. Then, we derive the analytical expressions of the secrecy outage probability (SOP) and ergodic secrecy rate (ESR) of the considered system with the BF strategy under an assumption that the satellite‐UAV link undergoes the shadowed‐Rician fading, while the UAV‐user link experiences the correlated Rayleigh fading. Finally, numerical results are given to demonstrate the superiority of the proposed BF scheme against zero forcing (ZF) and maximal ratio transmission (MRT) schemes and the validity of the secrecy performance analysis.

Specimen for the Determination of Fatigue Thresholds Under Cyclic Transverse Shear

We develop a basic element of the procedure of construction of the near-threshold part of the diagram of fatigue fracture for metallic materials under the conditions of transverse shear. It is proposed to use a square sample with edge cut and a force scheme of its cyclic loading. We determine the strain-stress state of a square plate with edge crack (regarded as a prototype of the proposed specimen) under the conditions of transverse shear by two independent methods (finite-element method and the method of singular integral equations). The stress intensity factor KII is determined for a broad interval of relative crack lengths with regard for the smooth contact of the crack faces and the presence of friction between the faces.

Numerical forcing scheme to generate passive scalar mixing on the centerline of turbulent round jets in a triply periodic box

Numerical studies of passive scalars in three-dimensional (3D) periodic box turbulence have often used arbitrary scalar forcing schemes to sustain the variance. These existing methods represent certain flow configurations, but they have not been derived using specific velocity and scalar profiles. In this work, a forcing technique is devised to generate centerline scalar mixing of round jets in a triply periodic box. It is derived from the scalar transport equation using a Reynolds-like decomposition of the scalar field. The equation is closed by applying the known mean velocity and scalar profiles of axisymmetric jets. The result is a combination of a mean gradient term and a linear scalar term. Direct numerical simulations at different Reλ have been performed with these source terms for unity Schmidt numbers. Scalar flux values and scaling exponents of energy spectra from simulations are comparable to experimental values. In addition, a dimensional analysis shows that the normalized scalar statistics, such as variance, flux, and dissipation rate, should only be a function of Reynolds number; indeed, such quantities computed from our simulations approach constant values as the Reynolds number increases. The effects of velocity forcing on scalar fields are also investigated; changing velocity forcing terms may result in unstable scalar fields even under the same scalar forcing. It may indicate that an appropriate relation between the velocity and scalar forcing schemes can help producing a proper scalar mixing environment.

Development and testing of an unstructured mesh method for whole plasma gyrokinetic simulations in realistic tokamak geometry

In this work, we have formulated and implemented a mixed unstructured mesh-based finite element–Fourier decomposition scheme for gyrokinetic simulations in realistic tokamak geometry. An efficient particle positioning (particle-triangle mapping) scheme for the charge deposition and field scattering using an intermediate grid as the search index for triangles has been implemented, and a significant speed-up by a factor of ∼30 is observed as compared with the brute force scheme for a medium-size simulation. The TRIMEG (TRIangular MEsh based Gyrokinetic) code has been developed. As an application, the ion temperature gradient (ITG) mode is simulated using the simplified gyrokinetic Vlasov-Poisson model. Our simulation and that using the ORB5 code for the DIII-D Cyclone case show reasonable agreement. As an additional application, ITG simulations using an ASDEX Upgrade equilibrium have been performed with density and temperature gradient profiles similar to the Cyclone case. Capabilities of the TRIMEG code for simulations with realistic experimental equilibria in the plasma core and in the whole plasma volume with open field lines are demonstrated.

Study of collisions between particles and unloaded bubbles with point-particle model embedded in the direct numerical simulation of turbulent flows

Simulations of a particle-bubble collision system composed of monosized spherical solid particles and air bubbles in a quiescent liquid and homogeneous isotropic turbulence have been performed using the pseudo-spectral method for the fluid flow and Lagrangian tracking for particles and bubbles. Particle-bubble collisions in a quiescent liquid were first simulated and compared to the existing theoretical models of particle-bubble collisions. Both numerical results and theoretical models indicate that decreasing bubble size and increasing particle size can increase the particle-bubble collision efficiency. A DNS model for studying the effect of turbulence on the collisions between particles and unloaded bubbles was then developed. A nonuniform time-dependent stochastic forcing scheme was implemented to maintain turbulence intensity at targeted levels. A statistical analysis of a group of particles and bubbles in the forced turbulent flow was performed to probe the mechanism of particle-bubble collision in a turbulent flow. A simplifying assumption (motivated purely by computational limitations) has been made that bubbles and particles can be randomly relocated during the simulation, unlike what happens in reality, but the size of the effect that this simplifying assumption will have on our results is unknown. Reductions in particle-bubble collisions due to preferential concentrations of particles and bubbles in different flow regions were not found. Comparing respectively the contributions of radial relative velocity and radial distribution function to the collision kernel, the contribution of radial distribution function could be neglected because the radial relative velocity increases by about 1900% (from 1.55 cm/s to 28.87 cm/s) while the radial distribution function decreases by only 33% (from 1.33 to 1.00). Collisions between particles and bubbles increased with turbulent dissipation rate primarily due to the fact that radial relative velocities between particles and bubbles increased with the flow dissipation rate.

A lattice Boltzmann study of the collisions in a particle-bubble system under turbulent flows

The Lattice Boltzmann and point particle methods are used to conduct direct numerical simulations of the collisions between particles and bubbles in homogeneous isotropic turbulence. Particle-bubble collision is a complicated process affected by many factors, and the effects of the turbulent flows and the parameters of a particle-bubble system on the collision process are studied. The effects of the preferential concentrations of particles and bubbles in the turbulent flows on the collision process are studied from the perspective of radial distribution functions. To maintain background turbulent flows at targeted turbulent levels, a non-uniform time-dependent large-scale stochastic forcing scheme was implemented within the mesoscopic multiple-relaxation-time LBM approach. A local peak was found in the radial distribution function when the parameters of the particle-bubble system or turbulent levels were changed. Nevertheless, the peak was not found in the collision kernel function as the effect of the preferential concentration was overwhelmed by the effect of the radial relative velocity. It is interesting to find that the distributions of particles and bubbles were affected by the turbulent energy dissipation rate in a way that local accumulations were most apparent when the Stokes number of particles was 1. Nevertheless, the radial distribution functions of particle-bubble pairs remained stable at 1 in the turbulent flows with varied turbulent energy dissipation rates. This means that the distributions of particles and bubbles are not correlated and the effects of individual preferential concentrations of particles and bubbles on the collisions between particles and bubbles are weak. Therefore, the collision kernels of particle-bubble pairs increased with turbulent energy dissipation rate in a similar way as the radial relative velocities between particles and bubbles increased with turbulent energy dissipation rate.

Smooth muscle contractility causes the gut to grow anisotropically.

The intestine is the most anisotropically shaped organ, but, when grown in culture, embryonic intestinal stem cells form star- or sphere-shaped organoids. Here, we present evidence that spontaneous tonic and phasic contractions of the circular smooth muscle of the embryonic gut cause short-timescale elongation of the organ by a purely mechanical, self-squeezing effect. We present an innovative culture set-up to achieve embryonic gut growth in culture and demonstrate by three different methods (embryological, pharmacological and microsurgical) that gut elongational growth is compromised when smooth muscle contractions are inhibited. We conclude that the cumulated short-term mechanical deformations induced by circular smooth muscle lead to long-term anisotropic growth of the gut, thus demonstrating a self-consistent way by which the function of this organ (peristalsis) directs its shape (morphogenesis). Our model correctly predicts that longitudinal smooth muscle differentiation later in embryogenesis slows down elongation, and that several mice models with defective gut smooth muscle contractility also exhibit gut growth defects. We lay out a comprehensive scheme of forces acting on the gut during embryogenesis and of their role in the morphogenesis of this organ. This knowledge will help design efficient in vitro organ growth protocols and handle gut growth pathologies such as short bowel syndrome.

Wetting boundaries for a ternary high-density-ratio lattice Boltzmann method

We extend a recently proposed ternary free-energy lattice Boltzmann model with high density contrast [Phys. Rev. Lett. 120, 234501 (2018)PRLTAO0031-900710.1103/PhysRevLett.120.234501] by incorporating wetting boundaries at solid walls. The approaches are based on forcing and geometric schemes, with implementations optimized for ternary (and, more generally, higher-order multicomponent) models. Advantages and disadvantages of each method are addressed by performing both static and dynamic tests, including the capillary filling dynamics of a liquid displacing the gas phase and the self-propelled motion of a train of drops. Furthermore, we measure dynamic angles and show that the slip length critically depends on the equilibrium value of the contact angles and whether it belongs to liquid-liquid or liquid-gas interfaces. These results validate the model capabilities of simulating complex ternary fluid dynamic problems near solid boundaries, for example, drop impact solid substrates covered by a lubricant layer.

Deformation, speed, and stability of droplet motion in closed electrowetting-based digital microfluidics

Electrowetting-based microdrop manipulation has received considerable attention owing to its wide applications in numerous scientific areas based on the digital microfluidics (DMF) technology. However, the techniques for highly precise droplet handling in such microscopic systems are still unclear. In this work, the deformation, speed, and stability of droplet transporting in closed electrowetting-based DMF systems are comprehensively investigated with both theoretical and numerical analyses. First, a theoretical model is derived which governs the droplet motion and includes the influences of the key electrowetting system parameters. After that, a finite volume formulation with a two-step projection method is used for solving the microfluidic flow on a fixed numerical domain. The liquid-gas interface of the droplet is tracked by a coupled level-set and volume-of-fluid method, and the surface tension at the interface is computed by the continuum surface force scheme. A parametric study has been carried out to examine the effects of the static contact angles (θs,ON and θs,OFF), hysteresis effect (Δθ), channel height (H), and electrode size (LE) on droplet shape, speed, and deformation during transport, which unanimously shows that droplet length, neck width, and transport stability are directly related to a dimensionless parameter κ* that only comprises θs,ON, θs,OFF, H, LE, and the hysteresis angle Δθ. Based on the results, the scaling laws for estimating droplet shape and stability of the transport process have been developed, which can be used for promoting the accuracy and efficiency of droplet manipulation in a large variety of droplet-based DMF applications.

INVESTIGATING THE MOTION OF SOIL PARTICLES ON SOIL BLADES OF WORKING BODIES OF DYNAMIC ACTION

The study of the motion of soil particles by soil blades of working bodies of dynamic action was carried out. The analysis of existing researches and publications, in which the main problem is highlighted, namely that the methodology of selecting blades, the analysis of the motion of soil particles on them at this time is not enough. As a result of the analysis of existing researches and publications, the purpose of research is set, namely: analytical researches, the result of which will allow to develop working bodies with predetermined parameters of blades and necessary modes of work, minimizing the path of passing particles of soil on them. The methodology of research is the analytical studies of the motion of particles of soil on the ground shovels. In studying the motion of soil particles on soil blades formed equations of motion of the particle of soil, and the speed of the soil fraction is obtained from the soil blade. The result of the research is a mathematical model of the motion of a soil particle on a soil-like blade, a scheme of forces acting on a soil particle has been developed, the force required for the emission of soil particles from soil blades has been obtained. As a result of the study of the motion of the soil particles by the soil-like blades of the working bodies of thedynamic action, the equations of the motion of the soil particle were obtained as a result of the transformations. An ellipsoid of rotation and an equation of force necessary for throwing the soil out of the soil elements were obtained. the practical value lies in the fact that the obtained equations allow designing the working bodies by ground treatment and the parameters of the blades that minimize the path of the passage of soil particles onto them. The originality lies in the fact that the resulting equations will allow the design of new working bodies of dynamic action with soil blades.

Analysis of force treatment in lattice Boltzmann equation method

In lattice Boltzmann equation (LBE), density distribution function is apparently relaxed to a given state fi(gs)(ρ,u∗) with an external/internal force, here ρ is fluid density and velocity u∗ can be different with physical velocity u. In the literature, it was shown that fi(0) should be fi(gs)(ρ,u∗), however, present work shows that fi(0) is fi(eq)(ρ,u) with different force scheme in single relaxation time LBE. The corresponding error terms are analyzed at Navier–Stokes level, and numerical results confirm our theoretical analysis.

On the entropic nature of unified interactions

In this paper, we generalize Verlinde’s entropic gravity proposal on the other fundamental interactions of nature. We begin by introducing the entropic origin of the Coulomb’s electrostatic force, and then the magnetic force, by assuming the holographic principle holds when a charged particle approaches a screen enclosing the emerged part of the spacetime due to a source. We assume that the entropy of the screen changes when the charge approaches as in the Verlinde’s approach. Thereafter, we obtain the entropic Maxwell equations in both classical and covariant form by means of the holographic principle hold for the source. Considering the gauge covariant structure of the fundamental forces, we implicitly generalize the entropic origin of the electromagnetic force into the strong and weak nuclear forces. The possibility of the entropic origin of the all fundamental forces of nature is assumed to make a meaningful contribution to the unification scheme of the fundamental forces.

Investigation on nonlinear and fractional derivative Zener model of coupled vehicle-track system

ABSTRACTThe nonlinear and fractional derivative Zener model of viscoelastic material considering Berg’s friction force model is established, which can be used to describe the frequency-dependent and amplitude-dependent behaviour of rubber isolator. The simplified Berg’s friction force scheme was proposed to improve computational efficiency in the frequency domain. The frequency response of the single degree of freedom system modelled with the fractional derivative Zener model and the proposed simplified Berg’s friction force scheme was investigated, and it agrees well with the results calculated by discrete Fourier transform. In addition, the fractional derivative Zener model and the proposed simplified Berg’s friction force scheme are implemented to model the rail pads and the primary suspension rubber spring in a railway vehicle, and then the nonlinear and fractional derivative Zener model of the coupled vehicle-track system was established. The frequency response calculated by the proposed nonlinear and fractional derivative Zener model of coupled vehicle-track system was compared to the calculation using ordinary Kelvin–Voigt model, and the results have shown that there is little difference in the calculation results between the two models, but the vibration responses of bogies, wheelsets and rails are quite different in time domain and frequency domain. Furthermore, the comparison between the proposed model and the fractional derivative Kelvin–Voigt model were analysed. The difference between the two models is small in the frequency range from 1 to 200 Hz and in the whole time domain, but the difference is large in the high frequency region. The proposed nonlinear and fractional derivative Zener model of the coupled vehicle-track system has high efficiency and accuracy both in time domain and frequency domain.Abbreviations: FDZ: fractional derivative Zener; SBFF: simplified Berg’s friction force; CVTS: coupled vehicle-track system; DFT: discrete Fourier transform; SDOF: single degree of freedom; FDKV: fractional derivative Kelvin–Voigt.

Assessment of the activation induced by neutron irradiation in K-DEMO and thermal response under the decay heat

The radioactivation of in-vessel components due to the fusion neutrons is an unavoidable trade-off in a tokamak reactor. We investigate the radioactivity level of nuclides and decay heat of conceptual water-cooled ceramic breeder blanket and divertor modules in K-DEMO, and demonstrate that a cooling scheme related to the decay time is important to prevent thermal failure of those components due to decay heat during their maintenance. For K-DEMO with a fusion power of 2.2 GW, the activation levels of blankets and divertors are evaluated regarding a regulatory low level limit in Korea. Total decay heat from radioactivated blankets and divertors reaches 63.4 MW after the full power operation of two years. In an outboard module, immediately after the plasma shutdown, local maximum temperature reaches 1300°C with the temperature difference up to 840 °C inside the module. Conservative natural convection was assumed to validate its integrity to remain within the allowable temperature range of the materials used, when provided that the cool-down time is secured at least a couple of days, the overall temperature of the module is reduced to about 200°C in 10 days. It is worth consideration that a forced convective scheme such an internal passage cooling can be tailored until a critical time corresponding to configurations of each module.

Movement of the top layer of the grain mixture on the vibrating grooved surface

The most unfavourable conditions for the implementation of separation arise in the case where the impurities and clean the grain evenly distributed. Therefore, a layer of granular grain mixture should be pre-prepared for participation in the process, which can be estimated by analyzing the kinematic parameters of the movement of grain particles, which is the purpose of this study. The description of the working body and the process of vibration movement of the grain mixture is given. To describe the vibrational movement of the grain mixture, a two-layer model is considered, in which changes are made due to the presence of riffles in the form of rectilinear plates on the support surface. In the study of the movement of the upper layer of the grain flow, we consider the movement of a material point on an inclined plane that makes horizontal harmonic oscillations perpendicular to the line of the greatest slope. Consideration of the scheme of forces acting on the particle in relative motion and the conditions of motion of the particle, made it possible to write the differential equation of relative motion in the projections on the coordinate axis. The transformations of the obtained dependences allowed us to determine the minimum force of inertia at which the relative motion will begin. By introducing the concepts and designations of the phase angles at which the relative sliding of a particle begins and ends, we determined the type of dependence of the particle velocity upon its sliding. The dependences of the particle movement in the positive and negative directions of the x and y axes, the dependence of the total displacements along the axes, as well as the average particle velocity along the x axis were obtained.the model of the two-layer vibrational movement of the grain flow along the surface with the riffles in the form of rectangular plates at their arrangement perpendicular to the direction of oscillations was Considered.

LBM study of aggregation of monosized spherical particles in homogeneous isotropic turbulence

Direct numerical simulations of an aggregation system composed of monosized spherical particles in homogeneous isotropic turbulence have been performed using Lattice Boltzmann method (LBM). The effects of hydrodynamics on the aggregation process were considered by directly resolving the disturbance flows around finite-size solid particles using an interpolated bounce-back scheme. A nonuniform time-dependent large-scale stochastic forcing scheme was implemented within the mesoscopic multiple-relaxation-time LBM approach to maintain turbulence intensity at targeted levels. To simulate particle interactions, the non-contact surface force and the contact force were taken into account using the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory and the soft-sphere model, respectively. This interface-resolved direct numerical simulation (IR-DNS) combined with the well-known DLVO theory was employed to obtain an insight into the aggregation process of micron-size particles. Specifically, the model was used to study the effects of solid volume fraction on aggregate growth. Aggregates of larger sizes formed in local regions of higher concentration of particles due to higher encountering probability between particles. The effects of aggregating particles of different volume fractions on the statistically stationary homogeneous isotropic turbulent flow were investigated. It was found that the presence of particles attenuated the turbulent kinetic energy at large scales and augmented the kinetic energy at the small scales. This effect is more apparent with increasing volume concentration of particles.

Lattice Boltzmann simulation of free surface flow impact on a structure.

Liquid impact on a rigid wall is a common feature in the context of marine structures, as most of them are exposed continuously to breaking waves. In the present paper, a comparison and analysis of the impact load estimates obtained from free surface lattice Boltzmann (LB) simulation with the experimental measurements from available literature have been reported. Initially, two-dimensional simulation of the dam break impact on the wall is performed with two different LB models: BGK-F1: a Bhatnagar-Gross-Krook (BGK) collision operator with the force scheme of Buick and Greated [Phys. Rev. E 61, 5307 (2000)1063-651X10.1103/PhysRevE.61.5307], and MRT-F2: a multiple relaxation time (MRT) operator with the force scheme of Guo etal. [Phys. Rev. E 65, 046308 (2002)1063-651X10.1103/PhysRevE.65.046308]. The pressure estimates obtained from BGK-F1 over MRT-F2 are closer to the measurements, though the other key parameters, such as the waterfront evolution and the free surface profile, have not shown significant variations. Furthermore, the three-dimensional dam break simulation has been performed using BGK-F1 for three test cases: (i) impact on a wall, (ii) impact on a rectangular obstacle, and (iii) impact on a tall tower. In all the test cases, the load estimates are in agreement with the experimental measurements.

A versatile lattice Boltzmann model for immiscible ternary fluid flows

We propose a lattice Boltzmann color-gradient model for immiscible ternary fluid flows, which is applicable to the fluids with a full range of interfacial tensions, especially in near-critical and critical states. An interfacial force for N-phase systems is derived and then introduced into the model using a body force scheme, which helps reduce spurious velocities. A generalized recoloring algorithm is applied to produce phase segregation and ensure immiscibility of three different fluids, where an enhanced form of segregation parameters is derived by considering the existence of Neumann’s triangle and the effect of the equilibrium contact angle in a three-phase junction. The proposed model is first validated by two typical examples, namely, the Young-Laplace test for a compound droplet and the spreading of a droplet between two stratified fluids. It is then used to study the structure and stability of double droplets in a static matrix. Consistent with the theoretical stability diagram, seven possible equilibrium morphologies are successfully reproduced by adjusting the interfacial tension ratio. By simulating near-critical and critical states of double droplets where the outcomes are very sensitive to the model accuracy, we show that the present model is advantageous to three-phase flow simulations and allows for accurate simulation of near-critical and critical states. Finally, we investigate the influence of interfacial tension ratio on the behavior of a compound droplet in a three-dimensional shear flow, and four different deformation and breakup modes are observed.