Gas Liquid Separator CFD Simulation, ANSYS Fluent TutorialDescriptionA gas-liquid separator is used across a wide range of industrial applications to separate a vapor-liquid mixture, and is variously known as a flash drum, break-pot, knock-out drum, knock-out pot, or — when specifically removing suspended water droplets from air streams — a demister. Separation itself is the fluid process by which mixtures of gas, liquid, and solid materials are divided into their component phases. Crude gas entering a refinery typically contains a mixture of gas, oil, and solids that must be separated before undergoing further processing, with oil and gas separators serving as a primary tool for dividing gas, crude oil, and water streams directly at the wellhead.While gas-oil separators can be built in vertical, horizontal, or spherical configurations, horizontal designs are the most common. This project simulates liquid-gas separation using a horizontal cylindrical separator, with an oil-gas mixture entering at mass flow rates of 3 kg/s (oil) and 0.15 kg/s (gas). Since oil is heavier than gas, it settles toward the bottom of the separator while the gas phase exits through the top outlet.The geometry was designed in Design Modeler as a horizontal cylinder, featuring a single horizontal inlet for the incoming mixture and two vertical outlets for the separated gas and liquid streams. The domain was meshed in ANSYS Meshing using an unstructured grid totaling 356,230 cells.MethodologyThis simulation models two phases — oil and hydrogen sulfide — using a multiphase approach. Since the phase boundary between them is sharply defined, the Volume of Fluid (VOF) model was applied, with hydrogen sulfide as the primary phase and oil as the secondary phase. The dispersed interface modeling option was used to capture the behavior at the boundary between the two phases.ConclusionResults include 2D and 3D contours of velocity, pressure, and the mass fractions of oil and gas, along with velocity vectors and streamlines throughout the separator. The results confirm that oil settles toward the lower portion of the separator due to its greater density, while hydrogen sulfide rises toward the top of the chamber due to its lighter weight — demonstrating that the separator system functions correctly, effectively dividing the oil and gas phases as intended.

Separator Two-Phase Flow, CFD Simulation ANSYS Fluent TrainingDescriptionThis project simulates the interaction between air and water flow within a separator chamber using ANSYS Fluent. The model represents a cylindrical separator chamber initially filled with water, with water entering through a vertical pipe at the top and exiting through a bottom pipe, while airflow enters and exits through horizontal tubes positioned on the chamber's lateral surface — the inlet lower on the side and the outlet higher up. The inlet air carries a mass flow rate of 0.001 kg/s, while the inlet water carries 0.1 kg/s.Since water is denser than air, it naturally settles toward the lower portion of the chamber while air occupies the space above the water surface. This two-phase arrangement was captured using the VOF multiphase model, with water as the primary phase and air as the secondary phase — an appropriate choice given the water forms a distinct free-surface layer rather than mixing with the surrounding air. Surface tension between the two phases was defined at 0.072 N/m to accurately capture this interface behavior.Geometry & MeshThe 3D geometry was designed in Design Modeler, representing a cylindrical chamber with vertical inlet and outlet pipes for water flow and horizontal inlet and outlet pipes for air flow. The domain was meshed in ANSYS Meshing using an unstructured grid totaling 972,786 elements.MethodologySeveral assumptions were applied: a pressure-based solver was used, the simulation was run under steady-state conditions, and gravitational effects were included at -9.81 m/s² along the vertical axis.Key simulation settings included:Viscous model: Standard k-epsilon with standard wall functionsMultiphase model: VOF with two Eulerian phases (water and air), implicit formulation, and dispersed interface modelingBoundary conditions: Separate mass flow inlets for gas (0.001 kg/s air, 0 kg/s water) and liquid (0.1 kg/s water, 0 kg/s air); pressure outlets for both gas and liquid streams at 0 Pa gauge pressure; stationary walls throughoutSolution methods: Coupled pressure-velocity coupling, PRESTO! for pressure discretization, and first-order upwind schemes for momentum, turbulent kinetic energy, turbulent dissipation rate, and volume fractionInitialization: Standard method, with the domain initialized to 0 Pa gauge pressure, zero velocity, an air volume fraction of 0, and a water volume fraction of 1ConclusionResults include 2D and 3D contours of mixture pressure, mixture velocity, and volume fraction for both the water and air phases. The results confirm the expected phase separation behavior: airflow moves upward due to its lower density, while water flow moves downward due to its greater density — demonstrating that the separator successfully divides the two phases as intended.

Cyclone by DPM, ANSYS Fluent CFD Simulation TrainingDescriptionThis project simulates a cyclone separator using the Discrete Phase Model (DPM) in ANSYS Fluent. Cyclones are among the most widely used industrial systems for air dewatering, dust disposal, and separating solid particles from gas flow, relying purely on centrifugal and gravitational forces to achieve separation — without the need for filters. Beyond reducing air pollution, cyclones also serve to reclaim solid particles back into the production cycle, and are commonly used in industries such as wood processing and cement production where suspended solid particles are a byproduct.Cyclones typically feature one inlet and two outlets: particle-laden air enters through the inlet and travels in a spiral, vortex-like pattern through the space between the inner and outer cylindrical bodies, keeping the solid particles suspended within the flow. Centrifugal force, combined with the particles' greater mass, drives them outward and eventually downward under gravity, separating them from the gas stream — while the cleaner gas flow continues upward, passing through the conical region before exiting through the upper outlet.Geometry & MeshThe 3D geometry was designed in Design Modeler, consisting of a cylindrical upper section transitioning into a partially conical lower section. A trapezoidal cross-section at the top serves as the dust-laden air inlet, with a circular cross-section forming the pure air outlet above it, while a circular cross-section at the bottom collects the separated dust particles. The domain was meshed in ANSYS Meshing using an unstructured grid totaling 142,499 elements.MethodologyGas flow continuously enters from the top into the space between the two cylinders and subsequently the conical section, while solid particles enter simultaneously as the discrete phase. The interaction between these two flows, combined with centrifugal force, drives their separation. In this simulation, air was defined as the continuous gas flow, with ash modeled as the discrete solid particle phase.This setup examines discrete-phase behavior from a Lagrangian perspective within a continuous Eulerian fluid — the gas flow is treated under the Eulerian framework, while the ash particles are tracked discretely under the Lagrangian framework. Since the continuous phase was assumed not to be affected by the discrete phase, the Interaction with Continuous Phase option was disabled for the DPM setup. The discrete phase injection was defined as inert at the cyclone inlet, meaning the particles exhibit no specific reactive behavior, allowing their trajectories and residence time to be tracked cleanly for performance analysis.ConclusionBy tracking the ash particles' trajectories and residence time throughout the cyclone, this simulation enables direct evaluation of separator performance — confirming how effectively the combined centrifugal and gravitational forces separate solid particles from the gas stream as they travel through the cyclone's cylindrical and conical geometry, consistent with the expected operating principle of this widely used industrial separation device.

Cyclone with the Motion of Particles, ANSYS Fluent CFD Simulation TrainingDescriptionThis project simulates the motion of particles within a cyclone using ANSYS Fluent, employing a one-way DPM approach to model the discrete phase. A cyclone is a device used to separate particles from a gas stream, with widespread applications across industrial processes.The 3D geometry was built in SpaceClaim, with a computational domain measuring 101 mm in both length and width, and 363 mm in height. The domain was meshed in ICEM CFD using an unstructured grid totaling 371,350 cells.MethodologySeveral assumptions were applied to the simulation: a pressure-based solver was used, the simulation was run as unsteady, and gravitational effects were included at -9.81 m/s².Key simulation settings included:Viscous model: Reynolds Stress modelDiscrete phase: Enabled with unsteady particle tracking; anthracite defined as the injected material, treated as inert, using a group injection typeBoundary conditions: Velocity inlet at 5.9 m/s with discrete phase set to escape; pressure outlet at 0 Pa gauge pressure with discrete phase set to escape; stationary walls with discrete phase set to reflectSolution methods: SIMPLE pressure-velocity coupling, second-order discretization for pressure, second-order upwind for momentum, and first-order upwind for the modified turbulent viscosityInitialization: Hybrid methodConclusionThe simulation captures particle motion behavior throughout the cyclone in detail. Most particles entering through the inlet exit through the lower outlet, while the air phase exits through the upper outlet — consistent with the expected separation mechanism. A small fraction of particles, however, become trapped in the upper region of the cyclone, continuing to rotate indefinitely rather than exiting through either outlet, highlighting a practical limitation in separation efficiency that can occur within real cyclone geometries.

Fly Ash Cyclone CFD Simulation, ANSYS Fluent TrainingDescriptionThis project simulates the motion of particles within a fly ash cyclone using ANSYS Fluent, employing a one-way DPM approach to model the discrete phase. A cyclone is a device used to separate particles from a gas stream, with widespread applications across industrial processes.A cyclone separator is a particulate control system used to limit particulate emissions into the atmosphere — efficient, cost-effective, and low in energy consumption. It separates particles of varying sizes from a gas stream using centrifugal force, and although the design is somewhat complex, its high separation efficiency more than compensates. Structurally, cyclones consist of an upper cylindrical barrel, where separation occurs, and a lower conical section, where separated particles are collected.The cyclone's flow field and separation performance are shaped by gas-solid interactions within it. Since particle loading remains relatively small, the presence of particles doesn't meaningfully alter the flow field, though the coupled particle effect on the surrounding stream remains significant. The separation principle relies on inertia: particles with higher density carry greater inertia, causing them to revolve at a larger radius. Heavier particles spiral outward toward the wall and slide downward, while lighter particles rotate closer to the center and are drawn out through the top.This simulation uses the Eulerian-Lagrangian technique: gas is treated as a continuum under the Eulerian framework, while individual solid particles are tracked through the flow field using Lagrangian tracking. Given the large density ratio between gas and particles, both drag and gravitational forces play a significant role in this simulation.Geometry & MeshThe 3D geometry was built in SpaceClaim and meshed in ANSYS Meshing using an unstructured grid totaling 1,028,959 cells.MethodologySeveral assumptions were applied to the simulation: a pressure-based solver was used, the simulation was run as unsteady, and gravitational effects were included at -9.81 m/s².Key simulation settings included:Viscous model: Reynolds Stress modelDiscrete phase: Enabled with unsteady particle tracking; anthracite defined as the injected material, treated as inert, using a group injection typeBoundary conditions: Velocity inlet at 5.9 m/s with discrete phase set to escape; pressure outlet at 0 Pa gauge pressure with discrete phase set to escape; stationary walls with discrete phase set to reflectSolution methods: SIMPLE pressure-velocity coupling, second-order discretization for pressure, first-order for momentum, and first-order upwind for the modified turbulent viscosityInitialization: Hybrid methodConclusionThe simulation examined particle motion throughout the cyclone alongside contours of particle velocity, pressure, and gas flow. The results confirm that lighter and heavier particles separate as expected, driven by the combined effects of centrifugal force and gravity. Most particles entering through the inlet exit through the lower outlet, while air exits through the upper outlet — though a small fraction of particles become trapped in the upper section of the cyclone rather than following either primary exit path, consistent with the separation behavior observed in similar cyclone configurations.

FCC Riser Gas-Solid Separation System, CFD Simulation, ANSYS Fluent TrainingDescriptionThis project simulates gas-solid flow within a fluid catalytic cracking (FCC) system using ANSYS Fluent. FCC systems are widely used in chemical process units to convert high-boiling-point oil fractions into lighter, higher-value products. Within an FCC reactor, two functionally distinct zones govern the process: a dilute upper zone called the disengager, responsible for separating oil vapor from catalyst particles, and a denser lower zone called the stripper.Since this system involves distinct interacting phases, the Eulerian multiphase model was used, solving separate momentum and conservation equations for each phase. Oil vapor, defined as the primary phase, carries a density of 3.471 kg/m³, specific heat capacity of 1006.43 J/kg·K, and thermal conductivity of 0.0242 W/m·K; the catalyst material, defined as the secondary phase, has a density of 1500 kg/m³, with its specific heat capacity and thermal conductivity derived from kinetic theory.Oil vapor enters the reactor through a dedicated steam inlet at 5.5 m/s and 300 K, while a combined catalyst-and-oil-vapor stream enters through a separate feed injection inlet at 18.57 m/s and 300 K. The simulation was run using an unsteady solver over 20 seconds, with a time step of 1 second.Geometry & MeshThe 3D geometry was designed in Design Modeler as a cylindrical reactor, modeling only a quarter of the geometry given its symmetrical structure, reducing computational cost. The upper portion of the model corresponds to the disengager, with the lower portion representing the stripper. The domain was meshed in ANSYS Meshing using an unstructured grid totaling 2,488,759 elements.MethodologySeveral assumptions were applied: a pressure-based solver was used, the simulation was run as unsteady, and gravitational effects were included at -9.81 m/s² along the z-axis.Key simulation settings included:Viscous model: Standard k-epsilon with standard wall functions; energy equation enabledMultiphase model: Eulerian, implicit formulation, with two phases (oil vapor and catalyst)Boundary conditions: Steam inlet with oil vapor at 5.5 m/s and catalyst at 0 m/s, both at 300 K; feed injection inlet with both oil vapor and catalyst at 18.57 m/s and 300 K; product outlet at 0 Pa gauge pressure; inner walls stationary with coupled thermal condition; baffles, disengager, and stripper walls stationary with zero heat fluxSolution methods: Phase Coupled SIMPLE for pressure-velocity coupling, PRESTO! for pressure discretization, second-order upwind for momentum, turbulent kinetic energy, turbulent dissipation rate, and energy, with QUICK scheme for volume fractionInitialization: Standard method, with 0 Pa gauge pressure, z-velocity of 18.57 m/s for both oil vapor and catalyst, 300 K for both phases, and a catalyst volume fraction of 0.6ConclusionResults include 3D contours of pressure, velocity, and volume fraction for each phase, captured at the final second (20 s) of the simulation. These results characterize how the oil vapor and catalyst phases distribute and separate within the reactor's disengager and stripper zones, offering insight directly relevant to optimizing FCC reactor design for efficient catalyst-product separation in real-world petrochemical refining operations.

Catalytic Reactor CFD Simulation by Eulerian Multiphase Flow, ANSYS Fluent TutorialDescriptionThis project simulates flow within a catalytic reactor using ANSYS Fluent. The 3D geometry was designed in Design Modeler as a vertically oriented cylindrical reactor, with four inlets positioned at the reactor's midsection for fuel injection, alongside a separate inlet for the catalytic material. The domain was meshed in ANSYS Meshing, totaling 430,586 elements.MethodologyWithin the reactor's internal structure, compressed air mixes with sprayed fuel and catalytic material to drive the reaction. Given the presence of multiple interacting phases, the Eulerian multiphase model was used, solving separate momentum and conservation equations for each phase individually.Three materials were defined for this multiphase system: air, serving as the primary phase with a density of 1.225 kg/m³; fuel, defined as a secondary phase with a density of 10 kg/m³; and catalytic material, also a secondary phase, with a density of 700 kg/m³. Airflow enters the reactor through a dedicated inlet at the reactor's lower section at a mass flow rate of 4.095 kg/s, while catalytic material enters through the reactor's middle pipe at 409.49 kg/s. Fuel enters through the four midsection injectors at a combined flow rate of 81.898 kg/s. Turbulence was resolved using the standard k-epsilon model.ConclusionResults include 2D and 3D contours of pressure, along with velocity and volume fraction for each of the three phases — air, fuel, and catalytic material. The results show air entering from the reactor's bottom and mixing with both the fuel and catalytic material streams entering from the reactor's midsection, confirming the expected multiphase mixing behavior central to the catalytic reaction process taking place within the reactor.

Bubble Columns Reactor CFD Simulation Using the VOF Model, ANSYS FluentDescriptionBubble columns find extensive use across the chemical, biochemical, and petrochemical sectors as multiphase contactors and reactors, offering advantages such as high heat and mass transfer rates, compact design, and low operating and maintenance costs. Three-phase bubble column reactors are particularly common in reaction engineering applications involving catalysts, as well as in biochemical processes where microorganisms act as solid suspensions to produce industrially valuable bioproducts. Understanding a bubble column's hydrodynamic behavior, heat and mass transfer processes, and flow regime characteristics has been substantially advanced through combined experimental and CFD-based investigation.ANSYS Fluent's Volume of Fluid (VOF) model — a homogeneous model suited to two- or multi-phase flows with a clearly defined interface — is well suited to capturing this behavior, using specialized discretization of the volume fraction equation to accurately resolve the interface between phases, provided the mesh remains sufficiently fine in interface regions.This project models the entry and flow of air bubbles into a water-filled environment, with three inlets of differing sizes introducing air bubbles into the domain. The smallest inlet carries a two-phase flow at 0.15 m/s with an air volume fraction of 0.75, while the other two inlets carry flow at 0.1 m/s with an air volume fraction of 0.7. A single outlet positioned at the middle of the upper boundary ensures mass conservation is satisfied throughout the domain.Geometry & MeshThe 2D geometry, featuring three distinct bubble entry positions, was built in Design Modeler and meshed in ANSYS Meshing, totaling 93,687 elements.MethodologyThe VOF multiphase model was used to simulate the interaction between air and water. Initial conditions placed air within the top 5% of the domain, with water occupying the remainder. Given the low velocities involved and the geometry's relative simplicity, the flow was treated as laminar, with the simulation run as transient throughout.ConclusionResults include 2D contours of pressure, velocity, viscosity, density, and volume fraction for both water and air. Air volume fraction was further examined across three subsections of the main domain to characterize how bubble distribution varies across different regions — these localized volume fractions serve as gas distribution parameters for each zone. Similarly, the overall air volume fraction across the entire domain, once the system reached a relatively stable state, was used as a mixing efficiency parameter, indicating the resulting air-water balance within the system after a given time.An animation of the bubble motion was also produced, illustrating how inlet size influences bubble movement and offering additional insight into the underlying flow physics governing bubble columns of this kind.

Erosion in an Obstruction Channel Using DPM, ANSYS Fluent TrainingDescriptionThis project simulates erosion within an obstruction channel using ANSYS Fluent's Discrete Phase Model (DPM), modeling the flow of impure water carrying sand particles and examining how these particles impact channel surfaces over time. The simulation models 1 mm diameter sand particles suspended in high-velocity water flow, tracking their trajectories and the resulting impact on channel surfaces, with particle residence time analyzed alongside the erosion patterns it produces.The geometry was designed in Design Modeler and meshed using a structured grid of over 1 million quad elements, with the solver configured for steady-state conditions to capture the erosion/accretion phenomena central to this analysis.MethodologyParticle-induced erosion was captured using DPM with two-way coupling, accurately representing the interaction between the sand particles and the surrounding water flow. The channel's obstruction geometry significantly shapes both the flow pattern and the resulting erosion behavior, generating high-velocity regions reaching up to 93.5 m/s at points where the flow is forced around the obstacle — these accelerated zones directly correlate with the locations most prone to erosion.Several established erosion theories — including the Oka, McLaury, and Finnie models — were applied to provide a comprehensive assessment of erosion behavior under these flow conditions, each offering a different perspective on how particle impact translates into surface wear.ConclusionThe results reveal a clear correlation between the channel's velocity and pressure gradients and the resulting erosion hotspots, with the obstruction's geometry playing a central role in determining where wear concentrates most heavily. By combining detailed particle trajectory tracking with multiple erosion models, this simulation provides a comprehensive picture of long-term wear behavior in obstructed channel flows — directly applicable to pipeline design, hydraulic machinery wear prediction, and maintenance planning across industries such as oil and gas, water treatment, and mineral processing.

Oil Jet Impact on the Water Tank (Three Phases), ANSYS Fluent Simulation TrainingDescriptionThis project simulates the impact of an oil jet on a water tank using ANSYS Fluent, modeling a system of three distinct fluids: air as the primary phase, along with liquid water and oil as secondary phases. The Eulerian multiphase model was used to capture the interaction between these three phases, with oil entering the domain at 8 m/s and gravity included at -9.81 m/s² along the y-axis.The 2D domain was designed in SpaceClaim, featuring a jet inlet, side boundaries defined as outlets, and the pipe side treated as a wall boundary. The domain was meshed in ANSYS Meshing using a structured grid totaling approximately 21,000 cells.MethodologyThe simulation used a 2D turbulent multiphase setup, applying the Multi-Fluid VOF (Eulerian-based) approach to capture the interaction between the three immiscible phases — oil, water, and air. Boundary conditions included the oil jet inlet, a pressure outlet, and no-slip wall boundaries throughout. A transient solver with fine time steps was used to accurately resolve the deforming interface and the dynamic behavior of the impinging jet as it strikes the water surface.ConclusionResults include 2D animations and contours of velocity, along with air and water volume fraction throughout the domain. The simulation begins with a domain containing only liquid water and air; as the oil jet enters and travels toward the water surface, the impact reveals the immiscibility of oil and water — rather than mixing, the oil pushes the water aside, displacing and splitting it, and generating a vortex at the point of impact.This simulation offers a clear illustration of how three heterogeneous, immiscible fluids interact within a single domain, capturing the resulting displacement and vortex formation that occurs when an oil jet strikes a water surface.