Two-way Coupling Model Research Articles

Experimental and Numerical Study on Fracture Characteristics of Interface between In Situ Engineered Cementitious Composites and Steel Deck

In this study, engineered cementitious composite (ECC) is used as the pavement of orthotropic steel deck bridge and an epoxy adhesive is used to achieve wet‐bonding between the steel deck and cast‐in‐place ECC. To investigate the fracture properties of bimaterial interface, the double cantilever beam (DCB) and 4‐point end notched flexure (4ENF) specimens were used to obtain the fracture toughness, and virtual crack closure technology (VCCT) was used to calculate the energy release rates. A mixed fracture criterion was also established based on the blister test in this study. In addition, for the phenomena of water accumulation in the interface cracks, the hydrodynamic pressure under load was evaluated with a two‐way fluid‐solid coupling model and the propagation mechanism of cracks at the water‐bearing interface was explored. The results showed that the energy release rates at the crack front showed obvious nonuniform distribution characteristics. The blister test indicated that a mixed fracture was in good agreement with the linear fracture criterion. The fracture effect produced by the hydrodynamic pressure of the interfacial water‐bearing crack was far less than the fracture toughness of the interface, which indicated that the hydrodynamic pressure could hardly destroy the interface at one time but might cause the erosion fatigue damage of the interface.

Drag enhancement in a dusty Kolmogorov flow

Particles suspended in a fluid exert feedback forces that can significantly impact the flow, altering the turbulent drag and velocity fluctuations. We study flow modulation induced by particles heavier than the carrier fluid in the framework of an Eulerian two-way coupled model, where particles are represented by a continuum density transported by a compressible velocity field, exchanging momentum with the fluid phase. We implement the model in direct numerical simulations of the turbulent Kolmogorov flow, a simplified setting allowing for studying the momentum balance and the turbulent drag in the absence of boundaries. We show that the amplitude of the mean flow and the turbulence intensity are reduced by increasing particle mass loading with the consequent enhancement of the friction coefficient. Surprisingly, turbulence suppression is stronger for particles of smaller inertia. We understand such a result by mapping the equations for dusty flow, in the limit of vanishing inertia, to a Newtonian flow with an effective forcing reduced by the increase in fluid density due to the presence of particles. We also discuss the negative feedback produced by turbophoresis which mitigates the effects of particles, especially with larger inertia, on the turbulent flow.

The Impact of Foreign SO2 Emissions on Aerosol Direct Radiative Effects in South Korea

This study examined the impact of foreign SO2 emission changes on the aerosol direct radiative effects (ADRE) in South Korea. Simulations that applied basic emissions (BASE) and simulations that applied reduced SO2 emissions from foreign sources (R_FSO2) were performed, respectively, using the Weather Research and Forecasting (WRF)-Community Multiscale Air Quality (CMAQ) two-way coupled model. In addition, the difference between the two experimental results was calculated (i.e., R_FSO2 minus BASE) to quantitatively identify the impact of foreign SO2 emission reduction. The reduction in foreign SO2 emissions caused a decrease in the concentration of SO2 flowing in from overseas to South Korea. As a result, a clear decrease in SO42− concentration was shown mainly in the southwest coast of South Korea. The difference in PM2.5 concentration in South Korea according to the foreign SO2 emission reduction did not correspond to the difference in SO42− concentration; it was determined in a complex way by the changes in SO42− concentration caused by SO2 concentration changes, and the subsequent series of changes in NO3− and NH4+ concentrations. The differences in SO42− and PM2.5 concentrations caused by the foreign SO2 reduction also affected the ADRE changes in South Korea. The distribution of ADRE difference between the two experiments was not consistent with the distribution of PM2.5 concentration difference, but it was very similar to the distribution of SO42− concentration difference. These results imply that the ADRE of South Korea is not simply proportional to PM2.5 concentration and may be determined by concentration changes of SO42−.

A novel two-way coupling model for Euler-Lagrange simulations of multiphase flow

We propose a novel approach for two-way coupled simulations of multiphase flows within an Eulerian-Lagrange framework. Lagrangian particles are commonly approximated as point sources of either energy, mass or momentum. To introduce them into the Eulerian computation of the fluid flow, an approximation of the Dirac delta function has to be made. By resorting to the Boundary Element Method (BEM) based computation of fluid flow, it is possible to implement the point source concept without any numerical approximation by simply taking advantage of the properties of the fundamental solution present in BEM. However, singularity issues occur in the close vicinity of the mesh nodes. To remedy this effect, the particle-in-cell (PIC) method is used. We present a novel hybrid BEM-PIC two-way coupling algorithm and show that the proposed BEM-PIC model gives superior results compared to a standard PIC implementation. We introduce a critical distance to separate the domain, where the BEM model can be used and the domain, where the PIC model should be used. The results show that the BEM model can be used in about 97%−99% of the domain depending on the mesh used. We provide a criterion for estimating the critical distance within the novel hybrid BEM-PIC two-way coupling algorithm.

Compressible multiphase particle-in-cell method (CMP-PIC) for full pattern flows of gas-particle system

The compressible multiphase flows in a gas-particle system often arise in many engineering applications and nature phenomena. This study focuses on the development of a novel method, i.e. the compressible multiphase particle-in-cell (CMP-PIC), which can be capable of simulating all pattern flows of gas-particle system from dilute to dense and granular flows. The equivalent relation of the momentum equations of the particle phase between the Baer and Nunziato (B-N) model and the MP-PIC model is the key support for the modeling of gas phase, particle phase and coupling effects. For the gas phase, the governing equations are constructed in the Eulerian frame and the B-N model is taken as reference to derive the equations of gas phase and two-way coupling terms. A transport five-equation model for multi-material compressible flows is adopted in gas equation. Additionally, the disperse particle is tracked in the Lagrangian coordinate based on the particle-in-cell (PIC) method. The collisions among particles are simulated with coarse-grained discrete element method (DEM) model which provides more physical manner rather than empirical collision stress model. Moreover, a two-way coupling model is derived based on a comparative study with B-N model. Thereafter a set of unified HLL/HLLC solvers is developed for the discretization of the convective and nozzling terms of gas phase equations. A high order interpolation operator with certain enlarged smooth length is applied for the robust computation of coupling effects. Overall, the advantages of traditional compressible two-fluid model, DEM and PIC model are integrated into the current CMP-PIC model, and it can simulate the transition flows from dilute to dense or vice versa, which is difficult for traditional methods. This Eulerian-Lagrangian approach is implemented in an in-house parallel code and validated against experimental observations involving different shock induced multiple phase flows. The qualitative and quantitative comparison shows that numerical results perform good consistence with experimental and theoretical results.

Impact of Electrification and Particle Loading on Velocity Profile of Dusty Fluid Flow Over a Stretching Sheet

The performance of incompressible, laminar, boundary- layer flows over a semi-infinite horizontal stretchable plate is considered. The dusty fluid flow problems are modelled and solved in agreement with two-way coupling model. The particle phase momentum equation in the vertical direction is considered where as that for fluid phase is neglected. Here the electrification term added in not from the supply from outside rather it is the generation due to collision of particles So the effects of particle loading and electrification on velocity profile have been studied. From the result analysis it is concluded that electrification and particle density have significant effect on particle phase velocity, whereas carrier fluid phase has negligible effect. The particle phase velocity increases with increasing of electrification parameter and decreases with increase of loading ratio.

Numerical Analysis of Supersonic Impinging Jet Flows of Particle-Gas Two Phases

Supersonic impinging jet flows always occur when aircrafts start short takeoff and vertical landing from the ground. Supersonic flows with residues produced by chemical reaction of fuel mixture have the potential of reducing aircraft performance and landing ground. The adverse flow conditions such as impinging force, high noise spectrum, and high shear stress always take place. Due to rare data on particle-gas impinging jet flows to date, three-dimensional numerical simulations were carried out to investigate supersonic impinging jet flows of particle-gas two phases in the present studies. A convergent sonic nozzle and a convergent-divergent supersonic nozzle were used to induce supersonic impinging jet flows. Discrete phase model (DPM), where interaction with continuous phase and two-way turbulence coupling model were considered, was used to simulate particle-gas flows. Effects of different particle diameter and Stokes number were investigated. Particle mass loading of 10% were considered for all simulations. Gas and particle velocity contours, wall shear stress, and impinging force on the ground surface were obtained to describe different phenomena inside impinging and wall jet flows of single gas phase and gas-particle two phases.

Ar-CO-liquid steel flow with decarburization chemical reaction in single snorkel refining furnace

As a new style refining equipment developed from the traditional RH furnace, Single Snorkel Refining Furnace (SSRF), which is also called as single snorkel RH, is widely used for producing ultra-low carbon steel. However, the effect of CO gas on fluid flow and decarburization is not reported in the existing literatures. Based on the Eulerian-Eulerian approach, a two-way coupling mathematical model considering CO gas is proposed to investigate the coupling phenomenon of Ar-CO-liquid steel flow and decarburization in SSRF. And the industrial experimental data is employed to validate the numerical result. In comparison with the one-way coupling model, the numerical result predicted by the two-way coupling model is closer to the industrial experimental data. The CO mole number, which is generated by the overall decarburization process, is about 3 times the argon mole number blown into the ladle, and the CO generation rate is greater than argon blowing rate at the first 12 min. Because of the stirring effect of CO gas, there are the more complex fluid flow, the stronger mass transfer, the greater decarburization rate and the lower carbon mass concentration in the liquid steel during decarburization. Besides, the Ar plume area predicted by the two-way coupling model is larger and it is closer to the center line of the snorkel. Therefore, the effect of CO gas on the fluid flow cannot be ignored and the two-way coupling model can describe the metallurgical phenomena in SSRF more precisely.

Two-way coupling calculation for multiphase flow and decarburization during RH refining

As an important secondary refining reaction, RH is good at degassing and decarburizing. In the past 40 years, many researchers developed many mathematical models to investigate the fluid flow and the decarburization in RH, but the effect of CO bubbles on the fluid flow is not considered because of the complicated mathematical model and the heavy computing load. In this paper, numerical results show that the numerical result predicted by the two-way coupling model is closer to the experimental data than that by the one-way coupling model. During the decarburization, CO mole number, which is produced by decarburization reaction, is about 3 times argon mole number blown into the up snorkel. And the CO generation rate is greater than argon blowing rate at the first 9 min. Therefore, the fluid flow in RH can be described correctly only on the condition of considering both CO bubbles and argon bubbles, and the two-way coupling model is the necessary model to have a deep insight into the metallurgical phenomena in RH vessel.

Development of a Two-Way Coupled Eulerian-Lagrangian Computational Magnetic Nanoparticle Targeting Model for Pulsatile Flow in a Patient-Specific Diseased Left Carotid Bifurcation Artery.

The aim of the present work is to present the development of a computational two-way coupled (fluid and particle coupled) magnetic nanoparticle targeting model to investigate the efficacy of magnetic drug targeting (MDT) in a patient-specific diseased left carotid bifurcation artery. MDT of therapeutic agents using multifunctional carrier particles has the potential to provide effective treatment of both cancer and cardiovascular disease by enabling a variety of localized treatment and diagnostic modalities while minimizing side effects. A computational model is developed to analyze pulsatile blood flow, particle motion, and particle capture efficiency in a diseased left carotid bifurcation artery using the magnetic properties of magnetite (Fe3O4) and equations describing the magnetic forces acting on particles produced by an external cylindrical electromagnetic coil. A Eulerian-Lagrangian technique is adopted to resolve the hemodynamic flow and the motion of particles under the influence of a magnetic field (Br= 2T). Particle diameter sizes of 20nm-4μm in diameter were considered. The computational simulations demonstrate that the greatest particle capture efficiency results for particle diameters within the micron range, specifically 4µm in regions where flow separation and vortices are at a minimum. It was also determined that the capture efficiency of particles decreases substantially with particle diameter, especially in the superparamagnetic regime. Particles larger than 2μm were targeted and captured at the desired location by the external magnetic field, and the largest capture efficiency observed was approximately 98%. The simulation results presented in the present work have shown to yield favorable capture efficiencies for micron range particles and a potential for enhancing capture efficiency of superparamagnetic particles in smaller arteries and/or using magnetized implants such as cardiovascular stents. The present work presents results for justifying further investigation of MDT as a treatment technique for cardiovascular disease.

Implementation of Open Boundaries within a Two-Way Coupled SPH Model to Simulate Nonlinear Wave–Structure Interactions

A two-way coupling between the Smoothed Particle Hydrodynamics (SPH) solver DualSPHysics and the Fully Nonlinear Potential Flow solver OceanWave3D is presented. At the coupling interfaces within the SPH numerical domain, an open boundary formulation is applied. An inlet and outlet zone are filled with buffer particles. At the inlet, horizontal orbital velocities and surface elevations calculated using OceanWave3D are imposed on the buffer particles. At the outlet, horizontal orbital velocities are imposed, but the surface elevation is extrapolated from the fluid domain. Velocity corrections are applied to avoid unwanted reflections in the SPH fluid domain. The SPH surface elevation is coupled back to OceanWave3D, where the originally calculated free surface is overwritten. The coupling methodology is validated using a 2D test case of a floating box. Additionally, a 3D proof of concept is shown where overtopping waves are acting on a heaving cylinder. The two-way coupled model (exchange of information in two directions between the coupled models) has proven to be capable of simulating wave propagation and wave–structure interaction problems with an acceptable accuracy with error values remaining below the smoothing length h S P H .

Investigation of vehicle stability under crosswind conditions based on coupling methods

In this study, vehicle stability under crosswind conditions is investigated. A two-way coupling method is established based on computational fluid dynamics and vehicle multi-body dynamics. Large eddy simulation is employed in the computational fluid dynamics model to compute the transient aerodynamic load, and the accuracy of the large eddy simulation is validated with a wind tunnel experiment. The arbitrary Lagrange–Euler technique is used in the computational fluid dynamics simulation to realise vehicle motion, and a real-time data transmission method is employed to ensure effective exchange of data between the computational fluid dynamics and multi-body dynamics models. The robustness of the two-way coupling model is verified by changing the position of the vehicle centroid. The results of the two-way and one-way coupling simulations demonstrate that crosswinds significantly affect vehicle stability. There is a clear difference between the results obtained with the two methods, particularly after the disappearance of the crosswind. The main reason for the difference is that the interaction between the transient airflow and the vehicle movement is considered in the two-way coupling method. Therefore, investigations of vehicle stability under crosswind conditions should consider the coupling of transient aerodynamic force and vehicle movement.

Effects of Plasma–Suspension Interaction on Axial Injection DC Suspension Plasma Spray

A rotationally axisymmetric 2-D numerical simulation of a dc suspension plasma spray (SPS) torch with an axial injection system is performed to discuss the interaction between the plasma fluid and suspensions. A two-way coupling model is used for modeling the behavior of plasma fluid and suspensions with mutual interaction effects through momentum and energy transfer. To deeply understand the mutual interaction effects, the numerical simulation using a one-way coupling model, in which the influence of suspensions on the characteristics of plasma fluid is not taken into account, is also performed for comparison. A suspension feed rate is parametrically varied to discuss its influence on the characteristics of plasma fluid and suspensions. Numerical results show that the two-way interaction substantially impacts the velocities and temperatures of plasma fluid and suspensions, and the trajectories of suspensions in the dc SPS torch with an axial injection system. It is also shown from the numerical results that the increase in suspension feed rate results in decreasing the electric current density around the central axis of the plasma torch and expanding the region with electric current in the radial direction.

Study on wake-induced fatigue on wind turbine blade based on elastic actuator line model and two-dimensional finite element model

Atmospheric and wake turbulence have a great and immediate impact on the fatigue life of wind turbine blades. Generally speaking, wake-induced fatigue accounts for 5%–15% increase of fatigue load on the wind turbine rotor, which definitely threats the safety and economy of the whole wind farm. However, this effect is difficult to simulate which involves multi-wake interaction and fluid structure interaction. To better simulate the wake-induced fatigue on wind turbine blades, a novel elastic actuator line model is employed in this study. The elastic actuator line is a two-way coupling model, consisting of traditional actuator line model and one-dimensional implicit or explicit finite difference method beam structural model, among which the beam model takes gravitational force, aerodynamic force and centrifugal force into consideration. Large eddy simulation method in the NREL SOWFA code is employed to model the turbulence effect, including wake-induced turbulence and atmospheric turbulence. For the fatigue analysis part, the fatigue life of an NREL 5MW turbine blade subjected to upstream wind turbine wake effects is studied using the elastic actuator line model and laminate data available from Sandia Laboratory in the United States. First, the strain and stress on different composite materials, such as uniaxial carbon fibre and biaxial composite material, are recovered by using the sectional force and moment obtained with the one-dimensional beam model and two-dimensional finite element method model, namely BECAS. Second, the stress-life method, rain-flow counting method, shifted Goodman diagram (constant life diagram) and Miners rule are employed to estimate the fatigue life for different composite materials. Noticeably, elastic actuator line largely reduces the computational efforts compared with a high-resolution computational fluid dynamics model, in which each wind turbine blade is fully resolved. Both the characteristics of different composite materials and airfoil geometries will be considered during fatigue analysis. As a result, the above procedure makes the fatigue life estimation more reliable and feasible. In the case studies, the moment time series predicted by elastic actuator line and FAST are compared. The fatigue damage of NREL 5MW wind turbine under turbulent neutral atmospheric boundary layer is calculated, and the fatigue critical section is determined to be at 10.25 m section from root. Finally, in the study of two in-line turbines, the fatigue damage increase by wake flow is 16%, which is close to the results from previous studies.

Numerical Simulation of Steel and Argon Gas Two-Phase Flow in Continuous Casting Using LES + VOF + DPM Model

A coupled three-dimensional model, including Large Eddy Simulation model, Lagrangian Discrete Phase Model and VOF multiphase model was developed to investigate the transient two-phase flow and bubble distribution in continuous casting strand. A two-way coupling model including the effect of the drag force, lift force, virtual mass force and pressure gradient force was adopted. The lift force was added via user defined function. A Rosin–Rammler bubble size distribution base on the water model was employed. The results show that the effect of the lift force cannot be ignored during the calculation of the steel and argon gas two-phase flow. Only the bubbles smaller than 2 mm would be brought to near the narrow face. With the increase of the argon flow rate, the transformation of the flow pattern from the double roll to complex flow and single roll was successfully predicted.

Simulation of the storm surge in the South China Sea based on the coupled sea-air model

Under global warming and climate change, coastal regions, including China, are increasingly vulnerable to typhoon damages. With typhoon gales, heavy rainfall, and storm surge, typhoons cause great economic losses and casualties to the coastal communities of China every year. Therefore, it is of great academic and social values to study the generation mechanism and movement mode of typhoons. However, accurately predicting the potential storm surge that a typhoon in growing can cause is a very challenging task. During the evolution of typhoons, the ocean-atmosphere (sea-air) interface has strong exchange of mass and energy. At the same time, various physical fields, such as wind, pressure, flow and wave fields interact strongly with each other. To accurately simulate the typhoons and the corresponding storm surge, the air-sea interaction is not to be neglected. Hence, it is very important to establish a reliable prediction model of sea-air coupling. In this paper, we established a fully two-way coupled sea-air model for South China Sea (SCS) by applying the mesoscale atmospheric model named WRF, the regional ocean model named ROMS, and the model coupling toolkit (MCT). In this complicated coupled sea-air model, WRF transfers the sea surface stress, net heat flux, sensible heat flux, latent heat flux, shortwave radiation flux, and longwave radiation flux to ROMS through MCT coupler. In turn, ROMS transfers sea surface temperature (SST) to WRF. By applying the fully coupled WRF-ROMS model, the storm surge induced by Typhoon Kai-tak , 2012 in the SCS is simulated and analyzed in detail. The computational capability and reliability of the coupled WRF-ROMS model are well verified by comparing the simulated typhoon track, and corresponding intensity and strength with the observed values in the field. The verification data show that the two-way coupled model has better accuracy and advantage in simulating typhoon dynamics than the one-way coupled model. Subsequently, the validated two-way coupled model is used to systematically study the atmospheric dynamics and the storm surge induced by typhoons in SCS. By analyzing the numerical simulation results, the wind and pressure field, as well as the spatial and temporal distribution characteristics of storm surge and wind-induced current, are obtained. We found that the spatial distribution of the wind, storm surge and flow fields caused by Typhoon Kai-tak is asymmetrical. The intensity of the typhoon on the right side of track is stronger than that on the left. Moreover, compared with the temporal evolution of typhoon, there is some delay in the evolution of the storm surge and the wind-induced current in the near shore.

Numerical investigation of the performance of moisture separators based on two-way coupling model by Lagrangian-Eulerian methodology

Moisture separator is one of the crucial equipment of the pressurized water reactor (PWR) nuclear power plant. In the separators, droplets could be regarded as the dispersed phase in terms of the gas–liquid two-phase flow. In order to predict the pressure drop of the droplet-laden flows in a more reasonable way, a fully two-way momentum coupling model based on the Lagrangian-Eulerian methodology is established. Then, a skilled self-programming code is implemented into the commercial CFD software FLUENT by the interface called User Defined Function (UDF) to solve this two-way coupling model. In the model application part, we first perform the numerical investigation of three different kinds of wave-type separators. The magnitude of the modeling separation efficiency and the changing trend of the pressure drop are in good agreement with the experimental data. Second, the gas–liquid flow in a swirl-vane separator is simulated under different operation conditions. The maximum relative error of the pressure drop by the two-way coupling model is over two times less than the simulation results by the one-way coupling model. Hence, the results show that the two-way coupling model, as well as the UDF solving program, performs a more comprehensive approach for the modeling of the gas–liquid two-phase flows in the moisture separators.

Heat Transfer Modulation by Inertial Particles in Particle-Laden Turbulent Channel Flow

We study the effects of particle-turbulence interactions on heat transfer in a particle-laden turbulent channel flow using an Eulerian–Lagrangian simulation approach, with direct numerical simulation (DNS) for turbulence and Lagrangian tracking for particles. A two-way coupling model is employed in which the momentum and energy exchange between the discrete particles and the continuous fluid phase is fully taken into account. Our study focuses on the modulations of the temperature field and heat transfer process by inertial particles with different particle momentum Stokes numbers (St), which in a combination of the particle-to-fluid specific heat ratio and the Prandtl number results in different particle heat Stokes numbers. It is found that as St increases, while the turbulent heat flux decreases due to the suppression of wall-normal turbulence velocity fluctuation, the particle feedback heat flux increases significantly and results in an increase in the total heat flux. The particle thermal feedback effect is illustrated using the instantaneous structures and statistics of the flow and temperature fields. The mechanisms of heat transfer modulation by inertial particles are investigated in detail. The budget of turbulent heat flux is examined. Moreover, by taking advantage of the ability of numerical simulation to address different momentum and heat processes separately, we investigate in detail the two processes of particles affecting heat transfer for the first time, namely the direct effect of particle thermal feedback to the fluid (i.e., heat feedback) and the indirect effect of the modulation of turbulent velocity field induced by the particles (i.e., momentum feedback). It is found that the contribution of heat transfer from turbulent convection is reduced by both heat and momentum feedback due to the decrease of the turbulent heat flux. The contribution of heat transfer from particle transport effects is barely influenced by the momentum feedback, even if St is large and is mainly affected by the heat feedback. Our results indicate that both heat and momentum feedback are important when the particle inertia is large, suggesting that both feedback processes need to be taken into account in computation and modeling.

Influence of incoming air conditions on fuel spray evaporation in an evaporating chamber

The main purpose of this article is to investigate the effects of pressure and temperature of incoming air into an evaporating chamber on fuel spray evaporation and fuel droplets characteristics. Before that, the influences of secondary break-up and coupling between droplets and gas phase on the present spray modeling are studied. An Eulerian-Lagrangian approach and two-way coupling model are implemented for modeling spray and atomization of liquid fuel in air. The SSTk-ω turbulence model is applied to estimate eddy viscosity, whilst the discrete random walk model is employed to trace the droplets in a turbulent flow. With increasing inlet air temperature from 373 to 573 K, the lifetime and penetration depth of droplets are reduced by about 70% and 46%, respectively. The influence of incoming air pressure on droplets lifetime is not remarkable. The penetration of droplets is reduced by almost 61% while augmenting the air pressure from 1.0 to 10.0 atm.

Validation of Lagrangian Two-Way Coupled Point-Particle Models in Large-Eddy Simulations

The accuracy of point-particle models with two-way coupling for particles of Kolmogorov-length-scale size is assessed. Turbulent kinetic energy budgets are analyzed in physical and in spectral space. It is shown that the force projection of the two-way coupling consistently models the direct transfer of kinetic energy on the particle surfaces and the enhanced viscous dissipation in the vicinity of the particles. Direct and large-eddy simulations of particle-laden flows in isotropic decaying turbulence are conducted and compared with direct-particle fluid simulations, where the particle-fluid interaction is fully resolved. An analysis in spectral space shows that turbulence modulation by particles mainly occurs at larger scales, although the momentum transfer takes place at the smallest scales. Therefore, the turbulent kinetic energy cascade of the single phase dominates in particle-laden flows. It is shown that point-particle models do not interfere with subgrid scale models, which usually act on the smallest scale. Consequently, point-particle models predict sufficiently accurate the turbulence modulation in direct numerical simulations and even when a subgrid scale model is used. The resolution of the LES does not affect the accuracy of the point-particle model, when the subgrid kinetic energy is negligible.