Particle Velocity Vector Research Articles

An analytical model of spatial correlation between vector fields of surface generated noise in a stratified ocean.

Traditionally, hydrophone-based acoustic pressure information has been utilized for underwater detection, but the advent of vector sensors has enabled the utilization of particle velocity of sound waves. A vector sensor adds three-axis particle velocity vector components to the conventional acoustic pressure sensor, representing spatial correlation not as a scalar function but as a matrix of four vector components. While analytical solutions exist for vector sensor spatial correlation in the case of simple isotropic noise, such noise fails to reflect the medium properties of the ocean, such as sound speed or density. Previous investigation reflecting the ocean environment derived a pressure spatial correlation model for surface generated noise in a stratified ocean, but this model is limited in the applicability to vector sensors. In this work, we extend the pressure spatial correlation model to vector fields, and by comparing with isotropic noise, we have confirmed that ocean environmental factors significantly influence the spatial correlation of vector sensors.

Simultaneous measurement of velocity field of liquid–solid particle flow in pipelines and analysis of flow characteristics

The liquid–solid particle flow within a horizontal pipeline is a typical particle-laden flow. The interplay between loaded particles and carrier phase engenders significant complexities in the dynamic behavior of such flows. We investigated the dynamics of a liquid–solid particle flow featuring dilute, slightly buoyant, hundred-micron-sized spherical particles fully suspended in the turbulent flow in a pipe, where Re is 7038. Cases with solid volume fractions of 0, 2.67 × 10-4, 5.33 × 10-4, 8.00 × 10-4, 1.07 × 10-3 and 1.33 × 10-3 were considered in this study. Experimental measurement techniques were utilized to acquire images of particles in the two-phase flow across the entire flow field via optical field feedback. Particle image velocimetry (PIV) and particle tracking velocimetry (PTV) were employed to simultaneously obtain liquid-phase velocity fields and particle trajectories. This approach allowed for a comprehensive depiction of the velocity field of each phase. Subsequently, a detailed explanation and analysis of the flow characteristics of the liquid–solid particle flow were provided based on the distribution of macroscopic velocity fields, the microscopic vorticity field, particle velocity vectors, and velocity slip. As a result, it was found that with the addition of solid particles and an increase in volume concentration, the drag effect of the solid phase and the trend of accumulation near the lower wall caused a decrease in the liquid phase velocity profile and deformation of the parabolic shape. In the liquid–solid particle flow with a volume concentration of 1.33 × 10-3, compared to the single-liquid phase flow, the standard deviation of velocity in the central region increased from 0.0097 m/s to 0.0159 m/s, and in the near-wall region, it increased from 0.0257 m/s to 0.0347 m/s, representing increases of 1.54 times and 1.26 times respectively. The proportion of medium vortices increased from 17 % to 30 %, nearly doubling. This study actively explores the concurrent measurement and flow characteristics of liquid–solid particle flow.

Three-Dimensional Visualization Of The Behavior Of Solid Particles Traveling In A Horizontal Gas Pipe Flow By Color PTV Using Discontinuously Changing Hue Illumination

In a gas pipe, a lot of solid particles remained during its construction. They are called dust and gas supply companies have tried to remove them using filters because they cause various problems. To optimize the maintenance period of dust removal filters, it is required to understand the behaviors of particles in the pipe. However, we do not fully understand yet because of their very complex behaviors caused by dune accumulated in the pipe. Furthermore, it is hard to investigate their behaviors with a traditional volumetric PTV using multiple cameras. Normally, its calibration is difficult because of the curvature of the pipe and the plural number of cameras. Therefore, we developed a new volumetric color PTV algorithm with discontinuously changing color illumination in the camera shooting direction, i.e. the depth direction. Color PTV can determine particle positions in three dimensions using a single camera but has low depth accuracy. Our new PTV measures particle positions and velocity vectors in the plane of picture using the same algorithm used in the normal planar PTV. On the other hand, particle positions and velocity vectors in the camera shooting direction are measured by a pattern of color changing on particle scattering light, which is our original method. To adopt the new volumetric PTV in the pipe flow, a volumetric light changing color discontinuously in the flow direction was irradiated and the particles were visualized using a camera installed at the outlet of the pipe. When a dune exists, the particles are thrown to the top of the pipe and their advection velocity is increased by the wakes generated by the dune. As a result, the dune makes more particles to be advected to a longer distance.

On the Method for Solving the Problem of Ice Cover Deformation under an Arbitrary Moving Load

Introduction. The development of the polar areas of the World Ocean and the need to solve various problems associated with a large number of freezing inland water bodies issue new challenges for science. These challenges include the problem of studying the behavior of ice cover when exposed to various types of loads. Of great interest is the consideration of problems about the action of a moving load on the ice cover. A moving load simulates the effect of moving vehicles on ice. However, in papers devoted to the above problems, cases of load movement along a straight-line trajectory are considered. The objective of this research is to develop a method for studying the behavior of ice cover under the action of a load moving arbitrarily.Materials and Methods. The article proposes a method for solving the problem of the action of a force moving along an arbitrary trajectory on the ice cover of a reservoir of finite depth. The problem amounts to solving a system of two differential equations. The first of them models the behavior of the ice cover, and it is the equation of vibrations of a viscoelastic plate. The second equation simulates the behavior of fluid in a state of potential flow, and it is Laplace's equation. To solve the system of differential equations, integral transformations in time, space and variables were used. The resulting solution was expressed through an iterated integral, which was calculated using numerical methods.Results. The development and implementation of the method resulted in solving the problem of the movement of a concentrated force along an ice cover according to an arbitrary law. At the same time, studies were carried out on the behavior of displacements and stresses in the ice cover depending on the speed and acceleration of the movement of the vertical load, on the depth of the reservoir, and on the viscoelastic properties of ice. In addition, the distribution of the velocity vector of fluid particles along the depth of the reservoir was calculated.Discussion and Conclusion. The proposed method is very effective for solving problems of moving loads acting on the ice cover of a reservoir of finite depth. It provides solving problems about the action of a load moving along an ice cover along a complex trajectory. The results obtained can be used to calculate the stress and displacement of the ice cover during the laying of ice roads or the construction of airfields on the ice.

Elliptical magnetic trajectories of a point on the elliptical 2-sphere

Elliptical trajectories play numerous significant roles in mathematics and physics. The focus of this work is to analyze the trajectories of a point on the ellipsoid S a 1 , a 2 , a 3 2 while it is under the influence of a killing vector field K. For this purpose, we introduce the generalized Darboux frame and the variational vector fields of S a 1 , a 2 , a 3 2 . We were able to get the trajectory equations of the charged particle on the ellipsoid by utilizing the elliptical structure and elliptic inner and cross product. We adopted a clearer and more comprehensible strategy in this way. With the aid of a mathematical program, we were able to display the paths we had determined based on the particle's velocity vector's position in the magnetic field. These trajectories are spiral, helical, and elliptical.

CFD Analysis for Valve-Holding Camber Permanent Inhaler Spacer (AerospaAcer) with Different Valves

During the COVID-19 pandemic, data statistics showed that patients with respiratory problems become infected. One of the therapy techniques for the respiratory condition was the use of a metered-dose inhaler and spacer. The objective of this paper is to determine the flow parameters of three types of valves which is duckbill valve, cross slit valve and umbrella valve in inhaler spacer to compare fluid flow between valve Previous researchers chose the duckbill valve to control fluid flow in inhaler spacer. The flow characteristics are unaffected by the materials used in the new disposable inhaler spacers, such as paper and polylactic acid (PLA). Several design valves reduced the skewness below 0.94 by suppressing the fillet and chamfer. ANSYS Workbench Fluent 19.2 is used to calculate flow parameters such as turbulence kinetic energy (TKE), turbulence eddy dissipation (TED), velocity, particle velocity magnitude, streamline, and vector velocity. The setup input data is based on the previous researcher's specified parameters such as viscosity model, drug characteristics (salbutamol and propellant), discrete phase model (DPM) equal to 80, boundary condition model, and SIMPLE technique. For the three types of valves, the nozzle injection used a 0.50-millimetre dimension. The simulation work is cross-checked against the results of prior simulations. Within each iteration, the transient flow employed a time step size of 0.01 for 200 steps. The results show that computational analysis can distinguish between models of varying complexity. The TED, TKE, and velocity graphs showed the approximate value between the model geometries. Overall, the study was successful in achieving the desired velocity magnitude in terms of visual and graph representations of the various valve.

Comparison and validation of various drag models for fluidization characteristics of bubble fluidized beds with a high-speed particle image velocimetry experiment

Bubbling liquefaction of dense particles is one of the most common forms of industrial fluidization in gas–solid flow systems. Computational fluid dynamics and the discrete element method are important tools for studying dense gas–solid flows. In these methods, the momentum transfer between phases relies on a drag model, so a reasonable choice of drag model is crucial for accurately predicting the hydrodynamic behavior of dense gas–solid flows. This paper investigates the effect of different drag models on the flow behavior prediction of dense gas–solid flow for the “Small-Scale Challenge Problem-I” published by the National Energy Technology Laboratory in 2013. The gas–solid fluidization characteristics, such as instantaneous particle flow processes, particle velocity vector distributions, changes in the fluidized bed height, and average gas phase pressure drops, were compared for different drag models. A detailed validation analysis of each dominant drag model was carried out in conjunction with the experimental data. The results show that the drag model significantly affects the numerically predicted results of particles’ hydrodynamic behavior, especially in terms of the bed height variation and the remixing behavior of particles. These research results are expected to improve the predictive accuracy of gas–solid flow hydrodynamic behavior and provide guidance for designing and optimizing fluidized beds, which has theoretical and practical significance.

A modified Pinto-Espinoza magnetization model for studying on motion characteristics of ferromagnetic particles

In this study, a modified Pinto-Espinoza (P-E) magnetization model that has a wider range of applications is proposed based on the conventional magnetization model. This model uses the relative reference frame conversion method to determine the magnetization force experienced by ferromagnetic particles when magnetic fields are applied in any direction. The accuracy of the improved P-E magnetization model is confirmed on the basis of this, and a coupled simulation environment between the discrete element method (DEM) and the finite volume method (FVM) is constructed. Simulated is the motion of ferromagnetic particles under various magnetic field directions and magnetic induction intensities. The particle distribution, particle velocity vector, and particle total energy change were all investigated. It is inferred that the chain formation direction of ferromagnetic particles in the magnetic field is consistent with the magnetic field direction, and they attract each other along the magnetic field direction and repel each other along the vertical magnetic field direction. Changing the intensity of the magnetic induction can effectively ease the particle delamination phenomenon. The faster the chain formation speed increases with increasing magnetic induction intensity, the shorter the time necessary to attain a stable condition.

Parabolic Cylindrical Description of Velocity and Acceleration Tensor in Bipolar Coordinate Using Tensor Analysis

Instantaneous velocity and acceleration are often studied and expressed in Cartesian, Circular Cylindrical, and Spherical Coordinate systems but it is a well-known fact that some bodies cannot be perfectly described in these coordinate systems, so they required some other curvilinear systems such as oblate spheroidal, parabolic cylindrical, elliptic cylindrical bipolar, and others. It is of important interest in theoretical physics to establish equations of motion in Bipolar Coordinate system, which is essentially suitable to accurately describe the motion of bipolar bodies such as hyperbolas, ellipses and other curves in the universe. In this work, we derived a new expression for the instantaneous velocity and acceleration vector of bodies and test particles in the bipolar coordinate system using tensor analysis. The Laplacian of a scalar field in this bipolar coordinate system was also derived which has applications in mechanics.

离心圆盘式有机肥撒施机改进设计与仿真分析

Aiming at the poor efficiency in crushing a handful of caking organic fertilizers spraying from the traditional disc spreader, an improved disc spreader equipped with spike-tooth crushing unit was designed with the introduction of its structural composition and working principle. Also simulation experiments were carried out based on the discrete element method according to the solutions made before and after the structural improvement. Firstly, a granular organic fertilizer model was established based on the EDEM and a caking organic fertilizer bonding model was built based on the HMB (Hertz-Mindlin with bonding) contact model. Then two organic fertilizer spreading models corresponding to the solutions were respectively established, based on which simulation experiments were repeated three times on the spreading process. The analysis on the particle velocity vector diagram revealed the interaction relationship between organic fertilizers with the toothed shaft, external wall and disk, verifying the crushing mechanism of crushing unit. By calculating the total number of the bonds generated and broken in the spreading process in both of the spreading models, the average broken rate of bonds in the spreading process was separately 58.87% and 98.05% based on each solution, revealing that the improved solution outperformed the traditional solution in terms of the efficiency in crushing the caking organic fertilizers. This research will be a reference in designing the critical components or improving the overall performance of disc spreader.

Method for Solving the Problem of Load Movement over the Ice Cover of a Reservoir along a Complex Trajectory

Introduction. The development of the polar regions of the World Ocean contributed to an increased interest in studying wave processes in water bodies with ice cover caused by the action of a mobile load. In most papers of domestic and foreign scientists, the ice sheet was considered as an elastic or viscoelastic plate loaded with a rectilinearly moving vertical force. However, when modeling the impact of vehicles on the ice cover, it is of interest to investigate problems in which the force moves along a more complex trajectory. Therefore, this study aims at developing a method for studying the behavior of the ice cover under the action of a force moving along a trajectory of a complex shape, obeying an arbitrary law of motion.Materials and Methods. A method for solving problems of the action of an arbitrarily moving force on the ice cover of a reservoir of finite depth filled with an inviscid incompressible fluid is proposed. The ice cover was considered as a viscoelastic plate lying on the surface of a liquid in a state of potential flow. A concentrated force moving along an arbitrary closed trajectory and being periodic in time was applied to the upper surface of the plate. Hydrodynamic pressure acted on the lower surface of the plate from the liquid side. Due to the periodicity of the load applied to the plate, an integral time transformation was used to solve differential equations describing the behavior of this system. Further, using traditional methods, formulas were obtained for calculating stresses and displacements in the plate and components of the velocity vector of liquid particles. These formulas were presented in the form of an iterated integral. Numerical methods were used to calculate integrals.Results. Calculations showed that the deflection of the ice cover increased markedly with the growth of speed and tangential acceleration of the load movement. An increase in the relaxation time of ice and a decrease in the radius of the trajectory of the load also caused an increase in deflection. The distribution of the fluid particle velocity vector over the depth of the reservoir was calculated.Discussion and Conclusions. The proposed method has shown its efficiency in solving problems about the impact of a moving load on the ice cover of a reservoir. With its help, the influence of the curvature of the trajectory of motion and the mechanical properties of ice, the kinematic characteristics of the movement of the load on the deflection of the ice cover was investigated. The method simulates the impact of vehicles on the ice cover of a reservoir. The results of its application can be used under the construction of ice roads or airdromes on ice.

Characteristics and Energy Distribution of Blast-Induced Ground Vibration in Deep-Hole Blasting

This study proposes an incremental extreme extraction method based on the waveform characteristics of ground vibration signals obtained from open-pit mines to investigate the distribution and characteristics of ground vibration from deep-hole blasting. Firstly, an incremental extreme extraction method is proposed based on the waveform characteristics of borehole blasting vibration signals in open-pit mines. The proposed method could extract and screen the extreme values of blasting vibration signals and effectively improve the utilization rate of the data. The space vector of particle vibration is introduced to analyze the angle change between the particle velocity vector and the ground surface when the extreme value increases. Finally, the relation between the particle velocity vector and the angle between the ground plane and the increasing extremum position of several sets of measured signals is studied. Based on the statistical analysis, the results show that the particle velocity in the vertical direction has a significant advantage over that of the other two directions, and the angle between the extreme particle velocity vector direction and the ground plane is primarily distributed in the range of 60°~90°. After an unstable distribution of particle velocities in the transition zone, the particle velocities in each direction gradually attain a relatively balanced and stable attenuation condition as the distance increases. This proves the reliability of the proposed vector analysis of particle velocity in understanding the mechanism of rock blasting.

Prediction of submicron particle dynamics in fibrous filter using deep convolutional neural networks

This study developed a data-driven model for the prediction of fluid–particle dynamics by coupling a flow surrogate model based on the deep convolutional neural network (CNN) and a Lagrangian particle tracking model based on the discrete phase model. The applicability of the model for the prediction of the single-fiber filtration efficiency (SFFE) for elliptical- and trilobal-shaped fibers was investigated. The ground-truth training data for the CNN flow surrogate model were obtained from a validated computational fluid dynamics (CFD) model for laminar incompressible flow. Details of fluid–particle dynamics parameters, including fluid and particle velocity vectors and contribution of Brownian and hydrodynamic forces, were examined to qualitatively and quantitatively evaluate the developed data-driven model. The CNN model with the U-net architecture provided highly accurate per-pixel predictions of velocity vectors and static pressure around the fibers with a speedup of more than three orders of magnitude compared with CFD simulations. Although SFFE was accurately predicted by the data-driven model, the uncertainties in the velocity predictions by the CNN flow surrogate model in low-velocity regions near the fibers resulted in deviations in the particle dynamics predictions. These flow uncertainties contributed to the random motion of particles due to Brownian diffusion and increased the probability of particles being captured by the fiber. The findings provide guidelines for the development of data science-based models for multiphysics fluid mechanics problems encountered in fibrous systems.

Substantiation of the main design parameters of the separation chamber of the pneumatic separator using various methods for calculating particle trajectories in the pneumoseparating channel

The article presents a study of the influence of methods for calculating particle trajectories in the pneumatic separation channel (PSC) on the design parameters of the separation chamber (length and height of the exit window), completed in 2013-2021. The field of air flow velocities and trajectories of spring wheat seed material components in the separation chamber of fractioning pneumatic seed separator was constructed. The initial data for the calculation were the information obtained earlier when calculating the trajectories of particles in the PSC by various methods. The location at the outlet of the channel, the value and direction of the particle velocity vectors were determined by computer modelling using the Solidworks Flow Simulation software package and two experimental and theoretical methods. They took into account the real velocity field of the air flow with and without grain load. The obtained values of the design parameters are compared with the results of experimental studies of the separation chamber. It should be noted that the methods of calculating the trajectories of grain impurity particles have a significant impact on the length of the separation chamber and the height of the exit window. The maximum length of the separation chamber of 0.75 m will be required for computer modelling of the velocity field in the PSC. Much smaller values of 0.50 m and 0.45 m will be required when calculating the trajectories of particles in the PSC using the velocity field obtained by experimental and theoretical methods. During the experimental study of the separation chamber during the cleaning of wheat seeds, the optimal length of the separation chamber was determined to be 0.55 m with an exit window height of 0.30 m. Thus, the values of the design parameters of the separation chamber obtained by experimental and theoretical methods are the closest to experimental data, which makes it possible to recommend them for use at the design stage of pneumatic separators.

Simulation of seismic velocity changes in brittle rocks subjected to triaxial stresses using 3-D microstructural models

SUMMARY Numerical simulation of non-linear elastic wave propagation in rocks is indispensable for understanding stress/damage dependence of wave velocity changes and the associated micromechanisms. A numerical microstructural model is presented here to investigate seismic velocity changes due to stress and damage. By introducing pre-existing cracks and considering the valid microstructures in the bonded particle model, the proposed method successfully reproduces velocity changes of experiments on dry Lac du Bonnet granite and dry Darley Dale sandstone in both loading and unloading processes. Velocity increasing results from the closure of pre-existing cracks during loading stages, while the reopen of cracks during the unloading process causes velocity decreasing. Particle velocity vectors are used to illustrate wave propagation in a micromechanical way. P wave wave fronts are observed from the source to travel through the model, and wave intersections are clearly shown in the medium when the tensile wave front meets the compressive wave. The microstructure of the model shows a significant effect on rock mechanical behaviour and velocities and lends credibility to the velocity simulation. The valid microstructure produces realistic mechanical behaviour and velocity changes. Also, it replicates the initial hardening in the axial stress versus the axial strain curve, while invalid microstructures (e.g. cement overlap) underestimate the elastic modulus. The simulations also show that the wave velocities scale with the square root of the corresponding component of the coordination number, which can be used to quantify the mechanisms behind the velocity changes. Direct relations were established between velocity changes and opened crack density, which displays a similar tendency compared with predictions of the effective elastic theory. The microstructural model provides the ability to simulate the macro behaviour of rock under loadings in a more realistic manner and to directly examine the microprocesses underlying velocity changes.

Shear Failure Mechanism and Numerical Simulation Analysis of Rock-like Materials with an Embedded Flaw

In this study, the failure characteristics of self-made rock with internal flaws under shear were studied and a numerical simulation analysis was carried out. Firstly, based on basic physical and mechanical tests, the shear strength characteristics of rocks with built-in 3D defects were summarized. PFC3D simulation software was used to model the samples with flaws, and the microscopic parameters were calibrated according to the test results. From the simulation results, it was found that the generation mode of microcracks from the flaw tip was different. The microcracks of forward shear and reverse shear were mainly generated from the horizontal direction, while the microcracks of lateral shear gradually increased from the upper and lower ends of the flaw in the opposite direction. When the peak shear strength was reached, the total number of cracks was the largest in lateral shear and the smallest in forward shear. When studying the particle velocity vector field, it was found that when reaching the peak shear strength, the particles on both sides of the prefabricated flaw appeared to be in vortex motion. When α = 45° and σn = 2 MPa, the failure mode of forward shear and lateral shear was shear-tensile-shear (S-T-S), and that of reverse shear and the intact specimen was shear-shear-shear (S-S-S). The lateral shear tensile effect was the most obvious and was mainly concentrated in the middle part of the sample.

Properties of the Acoustic Vector Field near the Underwater Planar Cavity Baffle and Its Application

In order to apply the acoustic vector hydrophone on a ship, the properties of the acoustic vector field near the underwater planar cavity baffle are studied based on the Euler description and Lagrange description. The acoustic vector field is calculated based on the transfer matrices and matched boundary conditions. It is shown that the interference structure appears in the acoustic field. In particular, the particle velocity direction and intensity vector cannot directly reflect the azimuth of the source. The points at which the particle velocity is zero are saddle points and nodal points in the particle velocity vector field. Moreover, the particle motion is generally an ellipse near the planar cavity baffle. Furthermore, this paper defines a parameter that can fully represent the particle motion, and the direction of arrival (DOA) can be estimated using a single acoustic vector hydrophone using this parameter in some cases. At the end, the validity of the theoretical calculation and the method of using the parameter to estimate the DOA are verified experimentally.

Experimental investigation of spout incoherence in a spouted bed

Spout incoherence is a typical instability phenomenon in spouted beds, in which the particles in the spout region move upward as groups, leading to poor spouting stability and efficiency. In this paper, the moving particle blockage in the spout region is measured to quantify the spout incoherence for the first time, by means of depicting the regularity, frequency and particle blockage length of the spout incoherence phenomenon. Specifically, the particle blockage is quantified using the particle concentration obtained by image processing method based on intensity differences between gas and solid phase in the spout centreline. The centreline of the spout channel is located by the particle velocity vector field. The method is validated by visual observation and frequency analysis. Then, the effects of static bed height and spouting velocity on the spout incoherence are investigated, respectively. The results show that the main features of spout incoherence, including frequency, regularity and particle blockage length, remain constant with varying spouting velocity in the investigated range. The results reveal that the static bed height has significant effects on the spout incoherence, and the increasing bed height reduces the frequency and particle blockage length of spout incoherence. This work quantifies the spout incoherence and unveil many interesting mysteries of the spout incoherence in spouted beds.

Detection of envelope modulation and direction of arrival estimation of multiple noise sources with an acoustic vector sensor.

The Detection of Envelope Modulation on Noise (DEMON) is an algorithm that is commonly applied to hydrophone data for the detection and classification of underwater noise produced by a ship. This algorithm utilizes modulation analysis to determine the frequencies that modulate the broadband cavitation noise produced by marine vessel propellers. In this paper, a DEMON demodulator for acoustic vector sensors (AVSs) that are directional hydrophones capable of acquiring both the acoustic pressure and the components of the particle velocity vector is defined. The proposed method is able to extract multiple modulating signals and measure their direction of arrival. The proposed receiver was validated with real data collected at sea with a moving buoyancy glider hosting an AVS.

CFD numerical simulation of standalone sand screen erosion due to gas-sand flow

Solid particles entrained in produced gas cause erosive damage in production and transportation facilities, that may eventually impact any process safety. The main purpose of this research is to determine the point on the Standalone screen (SAS) surface, where erosion rate is critical and to evaluate the uncertainties in the calculations and predictions of sand screen erosion utilizing CFD numerical simulation. A k-epsilon model was implemented to solve gas flow behavior and Discrete Phase Model (DPM) was used to track solid particles. The results of DPM were then introduced to conduct erosion simulation on the SAS utilizing four erosion equations. A full presentation of particle velocity vectors, particle velocity streamlines, total pressure contours and wall shear stress contours on the screen surface are presented and discussed. Additionally, the particle traces and path-lines are also demonstrated based on particles residence time as part of the particles’ trajectories. The erosion rates and erosion patterns from the four erosion equations, have shown similarities in their response to the change of sand characteristics. Considering the change in solid particles properties, a good agreement between CFD predictions and published data is achieved. This research can be used as a basis to offer safe operating guidelines for wells that are completed using standalone sand screens (SAS).