Oscillatory Wave and its Effect on Fin Motion, ANSYS Fluent CFD TrainingDescriptionThis project simulates the rotational motion of a fin within a two-phase flow field, driven by an oscillatory wave generated through ANSYS Fluent.The 2D geometry was designed in Design Modeler, divided into three main regions: structured, unstructured, and stationary. Meshing was carried out in ANSYS Meshing, totaling 120,049 elements. An unstructured mesh was applied specifically in the region surrounding the fin, since this area undergoes deformation through the dynamic mesh process and requires high flexibility to accommodate remeshing, while the remaining regions retain a structured mesh.The model is inherently unsteady, since it simulates the fin's rotational motion under a time-dependent oscillating fluid wave. Gravitational effects were included at 9.81 m/s² along the y-axis, given their influence on the torque acting on the fin.MethodologyThe two-phase flow was modeled using the VOF model, with air as the primary phase and water as the secondary phase, with no interaction or mass transfer between them. The motion of a rigid wall and its attached boundaries generates an oscillatory wave within the domain, which applies compressive force and shear stress to the fin mounted on the domain floor — causing the fin to rotate about its vertical axis as a rigid body.Since the problem requires boundary displacement, a dynamic mesh technique was used to capture the fluid flow, with a UDF defining the reciprocating motion of the scaffold wall responsible for generating the waveform. The simulation ran for 100 seconds with a time step of 0.001 s.Dynamic mesh smoothing was applied using a spring constant of 0.7, 500 iterations, and a convergence tolerance of 0.001, combined with the remeshing method using local cell sizing; spring-based smoothing alone was not used. The fin is constrained to a single degree of freedom (1-DOF), rotating about the z-axis around its pivot point, exhibiting reciprocating motion driven by wave impact. The moment of inertia applied to the fin was set to 0.1147 kg·m², equivalent to that of a rotating rod about its endpoint (I = 1/3·mL²).ConclusionThe results include 2D contours of pressure, velocity, and the volume fraction of air and water, along with pathlines captured at t = 2s. By enabling the write motion history option within the 6-DOF definition settings, the fin's x-y position and angular orientation were recorded over time as a dataset, producing a graph of the fin's angular displacement across the full 22.5-second simulation window.

Submarine Movement in Water by Dynamic Mesh (1-DOF), ANSYS FluentDescriptionThis simulation models the motion of a submarine in water using the Dynamic Mesh method in ANSYS Fluent, with a computational domain containing both air and water phases at a defined water level, with the submarine positioned within this domain.The submarine geometry was designed first, followed by a computational domain incorporating two-phase (air-water) flow around it. Both were modeled in 3D using Design Modeler. The domain includes distinct inlet and outlet sections, with symmetry conditions applied to the four surrounding faces.Meshing was carried out in ANSYS Meshing using an unstructured mesh totaling 316,846 elements.MethodologySince the submarine moves within the computational domain, affecting the surrounding grid elements, the mesh requires continuous, time-dependent updates based on the displacement occurring at adjacent mesh boundaries. This is achieved through the dynamic mesh model, applying smoothing and remeshing methods, with the submarine's wall defined as a Rigid Body.The submarine is constrained to a single degree of freedom (1-DOF), permitted to rotate only about its central axis (x-axis), with no translational or additional rotational motion. This rotational behavior is defined through a UDF, with rotational velocity varying between +1.5 rad/s and -1.5 rad/s over the 0–3 second simulation window.The rigid body settings also require specifying the spatial coordinates of the submarine's center of gravity and its axis of rotation.Since the domain contains two phases, the VOF multiphase model is applied, with air occupying the upper region and water the lower region. To represent the submarine operating in open sea conditions, wave behavior is introduced via the open channel wave boundary condition — incoming water enters at an average velocity of 10 m/s along the horizontal (x-axis), with the wave trough set at -10.16 m and its crest at 0 m. Inlet airflow enters at atmospheric pressure (zero relative pressure), with air discharged at atmospheric pressure as well.Given the dynamic mesh foundation of this model, the simulation is run as a transient (time-dependent) case, spanning 3 seconds with a time step of 0.01 seconds — necessarily unsteady due to the dynamic mesh method employed.ConclusionThe results include 2D contours of velocity and volume fraction for both water and air phases, along with 2D pathlines around the submarine — captured on a plane perpendicular to the submarine's horizontal axis (parallel to the Y-Z plane) at multiple points throughout the simulation.Consistent with the defined UDF, the submarine exhibits reciprocating rotational motion about its central axis, alternating between clockwise and counterclockwise rotation over the course of the simulation.

Self-Propelled Submarine Motion, Dynamic Mesh (6-DOF)DescriptionThis project simulates the motion of a self-propelled submarine floating on the water surface using the dynamic mesh method in ANSYS Fluent.This product is the fourth chapter of the Dynamic Mesh Training Course.The computational domain includes both air and water at a defined level, with the self-propelled submarine floating at the water's surface. The 3D geometry was designed using AutoCAD, CATIA, and ICEM CFD, with the submarine measuring 16.25 m in horizontal length and featuring several impellers with a diameter of 0.825 m at its rear.A cylindrical computational region was defined around the submarine within a larger cubic domain representing the full computational space. Meshing was carried out in ICEM CFD using a hybrid mesh — unstructured near the submarine hull, transitioning to a generally structured mesh across the remainder of the domain — totaling 2,802,219 elements.MethodologySince the grid cells shift position over time due to displacement at adjacent boundaries, the dynamic mesh model was used to capture this instantaneous grid movement. Three computational zones were established around the submarine, with smoothing and remeshing methods applied to handle the dynamic mesh behavior.Six degrees of freedom (6-DOF) were used to define the submarine's motion, allowing translational and rotational movement across all six directions. Mass and moment-of-inertia properties for the 6-DOF behavior were defined via a UDF.The submarine's hull was defined as a Rigid Body, along with a small surrounding cylindrical region also treated as rigid — together forming an integrated body capable of moving and rotating without internal mesh deformation. A larger cubic region surrounding this rigid zone was defined as a Deforming region to accommodate the motion. The rigid body definition also required specifying the submarine's center of gravity and its position within the model, with the submarine positioned floating at the water's surface.The VOF multiphase model was used to represent air in the upper portion of the domain and water in the lower portion, with both phases flowing horizontally (X-axis) at 1.62 m/s and exiting at atmospheric pressure. The open channel condition was applied at the outlet to define the water level, with the free surface set at 1.084824 m and the domain floor positioned at -100 m.Given the dynamic mesh foundation of this model, the simulation was run as transient, spanning 10 seconds with a time step of 0.001 seconds.ConclusionResults include 2D contours of velocity and volume fraction for both air and water phases across the floating submarine's surrounding regions, presented on the X-Y and Y-Z planes at the final second of the simulation. Additionally, diagrams tracking the submarine's translational and rotational displacement along all three axes (X, Y, Z) are provided, capturing the full 6-DOF motion behavior induced by the self-propulsion and surrounding flow conditions.

Fish Cage Floating on Seawater CFD Simulation by FSI Method, ANSYS FluentDescriptionThis project simulates a fish cage floating on the surface of seawater using the Fluid-Structure Interaction (FSI) method in ANSYS Fluent.The 3D geometry was designed in Design Modeler, representing a computational domain containing seawater, airflow, and a circular fish breeding cage. Since the model is perfectly symmetrical, only half of the geometry was modeled to reduce computational cost, with an inlet section, an outlet section, and symmetry conditions applied along the lateral faces.The domain was meshed in ANSYS Meshing, totaling 4,922,130 elements. Given the nature of FSI problems, a transient solver was used throughout.MethodologySince the fish breeding cage floats within the computational domain, seawater flow directly strikes the cage, requiring a two-way fluid-structure interaction to capture the coupled behavior between fluid and solid. This was implemented using the FSI method within the ANSYS Workbench environment.Because the fluid mesh structure changes around the geometry as the FSI simulation progresses, a Dynamic Mesh was required, using smoothing and remeshing methods to accommodate the time-dependent mesh changes. Two-way FSI was established through System Coupling in ANSYS Workbench, which required defining the model separately in both Fluent and Transient Structural, then coupling their solution processes.This coupling required two distinct data transfers: first, a Force transfer from the model wall in Fluent to the corresponding wall in Transient Structural — representing the force exerted on the cage as fluid flow strikes it; and second, a displacement transfer from the wall in Transient Structural back to Fluent — representing how the cage's structural deformation, in turn, alters the surrounding fluid flow.Since the fish cage operates within a two-phase domain (seawater and air), the VOF multiphase model was used, with air occupying the upper region and seawater the lower region. To represent the cage floating in open seawater, wave behavior was introduced via the Open Channel Wave boundary condition — incoming air and seawater entered at an average velocity of 3.08 m/s along the horizontal (y-axis), with the seawater floor set at -15 m and the free surface at 0 m. Airflow was discharged at atmospheric pressure.ConclusionResults were obtained from both Fluent and Transient Structural, all corresponding to the simulation's final time step (0.05 s). Transient Structural results include deformation, strain, and stress contours across the fish cage's structural body.Fluent results include 2D contours of velocity, pressure, and water/air volume fraction on the mid-plane (matching the symmetry plane), along with pressure distribution across the cage's body surface. The seawater wave surface itself was also extracted, showing 2D pressure and velocity contours and velocity vectors along it — clearly capturing the waves generated by the Open Channel Wave boundary condition in the volume fraction results.Structurally, the maximum deformation was observed in the thin connecting bars linking the cage's top and bottom holders — highlighting these as the most mechanically stressed components under the combined wave and current loading.

External Gear Pump CFD Simulation, Dynamic Mesh, ANSYS FluentDescriptionThis project simulates an external gear pump using ANSYS Fluent. A pump draws mechanical energy from an external source and transfers it to the fluid passing through, increasing the fluid's pressure and energy as it exits — a process achieved through either dynamic (non-positive displacement) or positive displacement methods. External gear pumps fall into the positive displacement category, moving liquid through the meshing action of two separate, externally-toothed gears.The geometry was designed in Design Modeler, representing the pump's internal computational domain around the two intermeshing external gears, and meshed in ANSYS Meshing.MethodologySince gear rotation continuously alters the fluid domain, the computational mesh must deform correspondingly over time — requiring the dynamic mesh model, used whenever a moving boundary or deforming zone is present. Each gear was defined as a Rigid Body to represent its rotational motion, with a custom UDF governing this motion, while the mesh region surrounding the gears was assigned the Deforming option to accommodate the continuous change as the gears rotate. Given the inherently time-dependent nature of the resulting fluid behavior, the simulation was run using an unsteady (transient) solver, with solver settings tuned to maintain accuracy and stability throughout the rotating, deforming-mesh solution process.ConclusionResults include pressure and velocity contours, along with animations capturing gear rotation and the resulting flow behavior throughout the pump. These results confirm the gear pump mechanism operates correctly — fluid becomes trapped in the space between the meshing gear teeth as they come together, then is carried and pushed toward the outlet at elevated pressure, reproducing the external gear pump's core operating principle and demonstrating effective fluid transfer and pressure increase throughout the cycle.

Internal Gear Pump CFD Simulation, ANSYS Fluent TrainingDescriptionThis project simulates an internal gear pump using ANSYS Fluent. A pump is a mechanical device that transfers liquid from one location to another, increasing fluid pressure to raise it to a higher elevation (via head increase) or drive it into another destination such as a tank. The pump draws mechanical energy from an external source, such as a motor, and transfers it to the fluid passing through, increasing the fluid's energy as it exits.Pumps transfer this energy through either dynamic or displacement methods, dividing them into dynamic (non-positive displacement) pumps and positive displacement pumps — the latter further split into rotary types (gear, lobe, vane) and reciprocating types (piston, diaphragm). A gear pump is among the most common types used to increase a fluid's hydraulic power, moving liquid through the meshing action of gears, and coming in two configurations: internal and external gear pumps.In an internal gear pump, two gears rotate in the same direction, with one nested inside the other. As the gear teeth mesh together, fluid becomes trapped between them; as rotation separates the teeth again, this high-pressure fluid is carried along the ribs toward the outlet. A crescent-shaped divider positioned between the inner and outer gears directs this flow path toward the outlet.The geometry was designed in Design Modeler, representing the pump's internal space with two non-concentric, intermeshing gears and the crescent divider positioned between them. The domain was meshed in ANSYS Meshing using an unstructured grid totaling 50,106 cells.MethodologyThis project simulates water flow inside the internal gear pump, focusing on capturing the rotation of both gears and its effect on the surrounding flow. Since this rotation continuously alters the fluid domain, the computational mesh must deform correspondingly over time — requiring the dynamic mesh model, used whenever a moving boundary or deforming zone is present.Since both gears rotate together, causing the mesh to deform over time, a Rigid Body was defined for each gear to represent its rotational motion, with a custom UDF governing this motion. The mesh region surrounding the gears was assigned the Deforming option to accommodate this continuous change. Given the inherently time-dependent nature of the resulting fluid behavior, the simulation was run using an unsteady (transient) solver.ConclusionResults include pressure and velocity contours along with velocity vectors, with corresponding animations capturing how these fields evolve as the gears rotate through their cycle. The results confirm that the gear pump operates correctly, effectively transferring fluid while raising its pressure: fluid becomes trapped in the space between the meshing gear teeth, then is pushed toward the outlet at elevated pressure — reproducing the internal gear pump's core operating principle as intended.

Gerotor Pump CFD Simulation, ANSYS Fluent TrainingDescriptionThis project simulates a gerotor pump using ANSYS Fluent. A pump is a mechanical device that transfers liquid from one location to another, increasing fluid pressure to raise it to a higher elevation (via head increase) or drive it into another destination such as a tank. The pump draws mechanical energy from an external source, such as a motor, and transfers it to the fluid passing through, increasing the fluid's energy as it exits.Pumps transfer this energy through either dynamic or displacement methods, dividing them into dynamic (non-positive displacement) pumps and positive displacement pumps — the latter further split into rotary types (gear, lobe, vane) and reciprocating types (piston, diaphragm). A gerotor pump is among the most common types used to increase a fluid's hydraulic power, moving liquid through the meshing action of two intermeshing gears rotating in the same direction, with one nested inside the other. As the gear teeth mesh together, fluid becomes trapped between them; as rotation separates the teeth again, this high-pressure fluid is carried along the ribs toward the outlet.A gerotor pump is essentially an internal gear pump without the crescent-shaped divider — the single structural distinction between the two designs.The geometry was designed in Design Modeler, representing the pump's internal space with two non-concentric, intermeshing gears. The domain was meshed in ANSYS Meshing using an unstructured grid totaling 51,182 cells.MethodologyThis project simulates water flow inside the gerotor pump, focusing on capturing the rotation of both gears and its effect on the surrounding flow. Since this rotation continuously alters the fluid domain, the computational mesh must deform correspondingly over time — requiring the dynamic mesh model, used whenever a moving boundary or deforming zone is present.Since both gears rotate together, causing the mesh to deform over time, a Rigid Body was defined for each gear to represent its rotational motion, with a custom UDF governing this motion. The mesh region surrounding the gears was assigned the Deforming option to accommodate this continuous change. Given the inherently time-dependent nature of the resulting fluid behavior, the simulation was run using an unsteady (transient) solver.ConclusionResults include pressure and velocity contours along with velocity vectors, with corresponding animations capturing how these fields evolve as the gears rotate through their cycle. The results confirm that the gerotor pump operates correctly, effectively transferring fluid while raising its pressure: fluid becomes trapped in the space between the meshing gear teeth, then is pushed toward the outlet at elevated pressure — reproducing the gerotor pump's core operating principle as intended.

Numerical Investigation of Cavitation Phenomena in a 2D Gerotor Pump Using ANSYS FluentDescriptionGerotor pumps play a crucial role in fluid transfer applications across modern hydraulic systems, but they frequently face challenges related to cavitation, which can significantly affect both performance and long-term durability. This study presents a detailed numerical investigation of cavitation behavior within a gerotor pump using a two-dimensional CFD model in ANSYS Fluent, aiming to understand and characterize how and where cavitation develops during pump operation.The 2D geometry was built in Design Modeler, accurately capturing the complex profiles of both the inner and outer rotors characteristic of gerotor pump design. The domain was meshed in ANSYS Meshing, generating approximately 50,000 elements — a mesh density chosen to balance computational efficiency against solution accuracy, particularly given the added demands of dynamic mesh operations required to capture rotor motion.MethodologyThe simulation used a pressure-based transient solver, with the SIMPLE algorithm handling pressure-velocity coupling. First-order upwind discretization was applied to momentum, volume fraction, and turbulence equations to maintain solution stability and convergence.Cavitation was captured using the Mixture multiphase model, with water as the primary liquid phase and water vapor as the secondary phase, representing the phase change driving cavitation formation. Turbulence was resolved using the RNG k-epsilon model, selected for its robust performance in rotating machinery applications.Rotor motion was implemented through dynamic mesh capabilities driven by custom UDFs, controlling the inner rotor at 30 rad/s and the outer rotor at 24 rad/s. Boundary conditions included a pressure inlet at 0 Pa gauge pressure and a pressure outlet, with all solid boundaries treated as standard no-slip walls.ConclusionThe simulation results provide comprehensive insight into the pump's operation and cavitation behavior. Pressure contours reveal regions of potential cavitation formation, concentrated specifically in low-pressure zones, while velocity contours illustrate the complex flow patterns within the pump, highlighting areas of high velocity and potential flow separation. Water volume fraction visualizations help pinpoint the specific zones where cavitation actually occurs during operation, with the accompanying animation capturing how the flow field and cavitation development evolve dynamically throughout the rotation cycle.The interaction between the rotating rotors and the fluid produces clear, identifiable patterns of pressure fluctuation and vapor formation, confirming that the numerical setup successfully captures the cavitation phenomena occurring within the gerotor pump. These findings offer valuable insight into how cavitation may affect pump performance and efficiency, and identify the critical regions where design modifications could help minimize cavitation effects — providing a solid foundation for future gerotor pump design improvement and optimization studies.

Lobe Pump CFD Simulation, ANSYS Fluent TrainingDescriptionThis project simulates a lobe pump using ANSYS Fluent. A pump is a mechanical device that transfers liquid from one location to another, increasing fluid pressure to raise it to a higher elevation (via head increase) or drive it into another destination such as a tank. The pump draws mechanical energy from an external source, such as an engine, and transfers it to the fluid passing through, increasing the fluid's energy as it exits.Pumps transfer this energy through either dynamic or displacement methods, dividing them into dynamic (non-positive displacement) pumps and positive displacement pumps — the latter further split into rotary types (gear, lobe, vane) and reciprocating types (piston, diaphragm). A lobe pump is among the most common types used to increase a fluid's hydraulic power, moving liquid using rotating lobes. Lobe pumps resemble gear pumps in operating principle, with one key difference: the lobes are designed to nearly meet rather than physically touch and turn one another.Lobe pumps consist of two lobes rotating in opposite directions. As the two lobes come together, fluid becomes trapped between them; as rotation separates the lobes again, this high-pressure fluid is carried through toward the outlet.The geometry was designed in Design Modeler, representing the pump's internal space with two superimposed lobes. The domain was meshed in ANSYS Meshing using an unstructured grid totaling 128,072 cells.MethodologyThis project simulates water flow inside the lobe pump, focusing on capturing the rotation of both lobes and its effect on the surrounding flow. Since this rotation continuously alters the fluid domain, the computational mesh must deform correspondingly over time — requiring the dynamic mesh model, used whenever a moving boundary or deforming zone is present.Since the two lobes rotate in opposite directions, causing the mesh to deform over time, a Rigid Body was defined for each lobe to represent its rotational motion, with a custom UDF governing this motion. The mesh region surrounding the lobes was assigned the Deforming option to accommodate this continuous change. Given the inherently time-dependent nature of the resulting fluid behavior, the simulation was run using an unsteady (transient) solver.ConclusionResults include pressure and velocity contours along with velocity vectors, with corresponding animations capturing how these fields evolve as the lobes rotate through their cycle. The results confirm that the lobe pump operates correctly, effectively transferring fluid while raising its pressure: fluid becomes trapped in the space between the contacting lobes, then is pushed toward the outlet at elevated pressure — reproducing the lobe pump's core operating principle as intended.

Twin Screw Extruder CFD Simulation, Using DEM and Dynamic Mesh, by ANSYS FluentDescriptionThis project simulates a twin screw extruder using ANSYS Fluent, modeling water flowing from the inlet at a specific flow rate while carrying suspended particles, with the particle flow rate set 9 times higher than that of the continuous phase. The simulation accounts for both the mutual interaction between the continuous and discrete phases, and the interaction between discrete particles themselves — implemented through a 4-way DEM (Discrete Element Method) module. The twin screw rotates at a constant rotational velocity of 300 rpm throughout the simulation.The geometry was designed in SpaceClaim, then transferred to ANSYS Meshing to generate an unstructured grid. Notably, the element count doesn't remain fixed — it changes continuously with each time step as the mesh adapts to the rotating screw geometry.MethodologyThe dynamic mesh module was activated with smoothing and remeshing sub-models to generate and modify the mesh at each time step as the twin screw rotates at its constant angular velocity. Turbulence was resolved using the standard k-epsilon model. The DPM model represented the discrete phase — CaCO₃ particles — with the 4-way DEM coupling capturing all relevant interactions: continuous-to-discrete, discrete-to-continuous, and particle-to-particle collisions.ConclusionThe computational cost of this simulation proved extremely high, driven by the combined demands of DEM and dynamic mesh. The initial mesh was built from 2.2 mm tetrahedral cells but changed continuously throughout the calculation as the geometry evolved. Time step size proved critical to convergence — an inappropriately sized time step could drive the solution to diverge due to negative cell volume detection as the mesh deformed.Following the simulation, particle tracking was extracted across a 60-degree rotation of the twin screw, with particle residence time contours presented from multiple viewing angles — together illustrating how particles move, mix, and reside within the extruder as the screws rotate, offering insight directly relevant to extruder design and process optimization for particle-laden flows.