DescriptionThis project uses ANSYS Fluent to simulate two-phase open channel flow, modeling the interaction between water and air inside a channel — a core problem in hydraulic and open-channel flow engineering. Open channels, whether natural (rivers) or artificial (canals, irrigation channels, water transmission systems), are widely used for water conveyance, transport, and irrigation. Water enters the channel at a mass flow rate of approximately 60 kg/s, and its interface behavior with the air phase above it is resolved using Fluent's open channel flow modeling capability.MethodologyThe geometry is built in DesignModeler and meshed in ANSYS Meshing using a structured grid of 214,560 elements. The simulation uses a pressure-based, steady-state solver, with gravity applied at -9.81 m/s² in the Y direction. Turbulence is modeled using the standard k-omega model with shear flow correction, while the VOF multiphase model with the open channel sub-model captures the water-air interface, with air as the primary phase and water as the secondary phase.Boundary conditions specify a mass flow inlet for water (60.071524 kg/s), with an open channel free surface level of 0.24 m and bottom level of 0 m, using density interpolation from neighboring cells. The outlet is set as a pressure outlet, and walls are treated as stationary. The solution uses the SIMPLE scheme for pressure-velocity coupling, PRESTO! for pressure discretization, second-order upwind for momentum, a compressive scheme for volume fraction, and first-order upwind for turbulent kinetic energy and dissipation rate. Standard initialization is applied with zero gauge pressure, zero velocity, and a water volume fraction of 0.ConclusionResults include 3D and 2D contours of velocity, pressure, and water volume fraction, characterizing the flow behavior and free-surface interaction within the open channel.

Counterflow within a Canal — ANSYS Fluent CFD SimulationDescriptionThis project uses ANSYS Fluent to simulate counterflow in a canal and analyze the resulting fluid behavior. The setup features a main water stream moving along the canal while a second stream is injected in the opposite direction from a floor-mounted pipe. The opposing jet disturbs the flow and the free surface, creating a localized interaction between the two streams that is characteristic of many practical canal and hydraulic-mixing situations. Within the Free Surface Flow: Beginner CFD Training Package, this project builds on the basic open-channel case by introducing two interacting streams, adding complexity to the free-surface behavior captured with the VOF method.MethodologyThe 3D geometry, built in DesignModeler, represents a straight channel 8 m long with a 3 m × 1 m rectangular cross-section, with a 4 m long pipe of 0.05 m diameter lying along the canal floor. Meshing in ANSYS Meshing yields 256,899 elements, and a transient solver is used. The main channel inflow velocity is 0.3 m/s, while the pipe issues flow at 2 m/s in the opposite direction. The region above the water surface is open to air, represented by a pressure-inlet boundary at 0 Pa gauge for ambient conditions. Because both water and air are present, a VOF multiphase model is employed, with the standard k–ε model for turbulence.AnalysisPost-processing provides 2D and 3D fields of pressure, velocity, and phase volume fraction for water and air. The opposing jet perturbs the free surface and entrains air, producing zones with a locally reduced water volume fraction where the counterflow interacts with the main stream. From these results you can evaluate how the opposing jet disturbs the main flow, how air is entrained at the free surface, and where the strongest mixing and interaction between the two streams occurs.

Open Channel with a Side Outlet — ANSYS Fluent CFD SimulationDescriptionThis project simulates free-surface flow through an open channel using ANSYS Fluent, with the open-channel flow model as its central theme. An open channel is a waterway — natural or artificial — used to convey water for purposes such as transport, service-water supply, and irrigation; in effect, an engineered version of a river. Canals of this kind are widely used in industry, from water-transmission systems to air ducts, and their shape and dimensions are dictated by their intended use. The defining feature of such flows, and the core of this study, is the presence of a free surface between water and the air above it, which must be tracked accurately as the flow develops. Within the Free Surface Flow: Beginner CFD Training Package, this project adds a branch to the open-channel progression, introducing flow diversion into a side outlet.MethodologyThe configuration studied here is an open channel with a 180° bend and a side outlet. Water enters the canal at a mass flow rate of 45 kg/s, and partway through the bent section a set of obstacles reduces the flow pressure and diverts a portion of the incoming water into the side outlet — representing water drawn off to irrigate an adjacent farm. The aim is to understand how the bend, the obstacles, and the side outlet together govern the flow distribution, pressure field, and water level within the channel. The geometry was created in Gambit and meshed in ANSYS Meshing with an unstructured grid of 178,093 cells. Because two phases — water and air — are present with a sharp, well-defined interface between them, the simulation uses a multiphase approach built on the Volume of Fluid (VOF) model. VOF is the natural choice for open-channel flow precisely because the phase boundary is distinct: it tracks the fraction of each cell occupied by water versus air and so resolves the free surface directly. To set up the problem, the initial water level is specified, with water filling the channel to a depth of 0.15 m and air occupying the region above it.AnalysisAfter solving, the simulation yields contours of velocity, pressure, and the volume fraction of water and air. The pressure field shows elevated pressure in the lower part of the channel, where the water column stands to its defined level, consistent with the expected hydrostatic behavior. The volume-fraction contours correctly capture the stratified arrangement of the two phases — water occupying the lower portion of the channel and air flowing above it — confirming that the VOF model reproduces the free surface faithfully. By the end of this project, you'll be able to set up an open-channel VOF simulation with a defined initial water level, model flow diversion into a side outlet, and interpret the velocity, pressure, and volume-fraction fields to analyze flow distribution and water levels in practical canal and irrigation applications.

DescriptionThis project simulates two-phase flow of water and air inside an open channel with a 180-degree bend using ANSYS Fluent. This is fundamentally a free-surface flow problem: the water moves with an open, deformable interface between the liquid and the air above it, and accurately capturing the position and shape of that free surface is the central modeling challenge. To handle it, the multiphase VOF (Volume of Fluid) model is used — the standard approach for free-surface currents — with air defined as the primary phase and water as the secondary phase. Because the water flows with a free surface inside the channel, the open channel flow sub-model is also employed, with the water level set at 0.2 m.A stream of water 0.2 m deep, with a mass flow rate of 94.83 kg/s, enters the channel and, after traveling through the 180-degree arc, exits the outlet at atmospheric pressure. For the upper boundary of the channel — where air passes — a relative pressure condition of 0 Pa is applied.Geometry & MeshThe model was built in 3D using Design Modeler. It is a channel with a rectangular cross-section following a 180-degree arc; the cross-section is 1 m wide and 0.7 m high. Meshing was performed in ANSYS Meshing using a structured grid of 2,316,480 elements, shown in the figure below.MethodologySeveral assumptions underpin the simulation: a pressure-based solver is used, the simulation is steady, and gravity acts at −9.81 m/s² along the vertical axis.Viscous model — RNG k-epsilon with standard wall functionsMultiphase model — VOF with 2 Eulerian phases (air and water), implicit formulation, the open channel flow sub-model, and sharp interface modelingBoundary conditions — Inlet: mass flow inlet with a free-surface water level of 0.2 m, bottom level of 0 m, water mass flow rate of 94.83 kg/s, and air mass flow rate of 0 kg/s; Outlet and top: pressure outlet at 0 Pa gauge; inner, outer, and bottom walls: stationaryMethods — SIMPLE pressure-velocity coupling; second-order for pressure; second-order upwind for momentum; compressive scheme for volume fraction; first-order upwind for turbulent kinetic energy and turbulent dissipation rateInitialization — standard method, with 0 Pa gauge pressure, zero velocity in all directions, water volume fraction 0, and air volume fraction 1ConclusionOn completion of the solution, three-dimensional contours of pressure, velocity, turbulent kinetic energy, and the volume fractions of water and air within the 180-degree bend were obtained. Because the VOF model tracks the free surface directly, the results reveal how the water surface deforms as the flow negotiates the curve — including the superelevation of the water on the outer wall of the bend, where the centripetal effect raises the free surface, and the corresponding drop along the inner wall. This redistribution of water depth and velocity around the arc is precisely the behavior that free-surface modeling is designed to capture, making the VOF and open-channel approach essential to obtaining physically meaningful results.

Ogee Spillway — ANSYS Fluent CFD SimulationDescriptionWelcome to the Ogee Spillway CFD Simulation module. This project introduces civil and hydraulic engineers to computational fluid dynamics applied to spillway design and analysis using ANSYS Fluent. A spillway is a critical safety component of a dam, regulating the water level and safely passing flood flows, and the ogee (S-shaped) profile is one of the most widely used because it guides the flow smoothly while efficiently dissipating its energy. Understanding the hydraulic behavior of an ogee spillway — its flow pattern, its surface pressures, and how it dissipates energy — is central to effective dam engineering and flood control. Within the Free Surface Flow: Beginner CFD Training Package, this project marks the move from open channels into hydraulic structures, applying the VOF free-surface method to flow over a spillway.MethodologyThe workflow begins with creating a basic geometry representing an ogee spillway and applying an appropriate meshing strategy for accurate flow analysis. The water properties are defined in ANSYS Fluent, and the boundary conditions are set to represent the spillway scenario — inlet flow rates and outlet pressure conditions, together with wall and free-surface boundary conditions for the spillway surface and the water–air interface. The solver parameters, including time-stepping and convergence criteria, are configured to suit a spillway hydraulic simulation, and the solution is monitored for stability and convergence throughout. The setup captures the free surface as the water accelerates over the ogee profile, allowing both the flow pattern and the surface loading to be resolved.AnalysisPost-processing focuses on the velocity and pressure behavior over the spillway. Velocity fields and streamlines are visualized to understand how the flow develops along the ogee profile, while pressure profiles along the spillway surface are examined to assess hydraulic loads and potential cavitation risks. The energy-dissipation characteristics are then analyzed to reveal how the spillway reduces the energy of the high-velocity flow and protects downstream structures. By the end of this project, you'll be able to set up and run a basic ogee spillway simulation in ANSYS Fluent, capture flow patterns and surface pressure distributions, interpret the energy-dissipation behavior, and apply those insights to spillway design and performance evaluation for dam engineering and flood control.

Spillway (2-D & Transient), Two-Phase Flow — ANSYS Fluent CFD SimulationDescriptionThis project simulates the two-phase flow of water and air over an ogee spillway — the curved overflow structure used in dams to pass excess water safely downstream. When flow meets an obstruction, the water level rises behind it and accelerates over the crest; an ogee profile is shaped specifically to match the natural nappe of falling water, minimizing pressure problems and maximizing discharge efficiency. Capturing the free water surface as it spills over the crest is the core of the problem and a classic application of free-surface CFD in civil and hydraulic engineering. Within the Free Surface Flow: Beginner CFD Training Package, this project builds on the ogee spillway case by solving it as a fully transient two-phase problem, watching the free surface develop over the crest in time.MethodologyThe physics is handled with the Volume of Fluid (VOF) multiphase model, which tracks the sharp air–water interface as it deforms over the spillway, with the standard k-ε model closing the turbulence. Because the whole point is to watch the water move, accelerate, and form its surface profile over the crest, the case is solved as transient. Water enters the computational domain at a mass flow rate of 0.05 kg/s and flows over the spillway against the air phase. The geometry is built in ANSYS Design Modeler and meshed in ANSYS Meshing with a structured mesh of 12,846 elements — structured here because the spillway's smooth, well-defined geometry suits a clean, aligned grid along the flow path.AnalysisContours of pressure, velocity, and phase volume fraction are extracted across the domain, revealing the water surface profile over the crest, the acceleration of the flow down the spillway face, and the pressure distribution along the structure — exactly the quantities a hydraulic engineer uses to assess discharge capacity and surface pressures. The project includes the geometry and mesh file plus a comprehensive training movie walking through the full setup, solution, and extraction of all results. By the end of this project, you'll be able to set up a transient VOF air–water free-surface case, define mass-flow inflow over a curved spillway, apply standard k-ε turbulence, and read the free-surface profile and pressure field from volume-fraction and pressure contours.

Wide-Edge (Broad-Crested) Spillway — ANSYS Fluent CFD Simulation TrainingIntroductionA wide-edge (broad-crested) spillway is a cascading structure with a long horizontal crown aligned with the flow direction, such that the error arising from the hydrostatic pressure distribution can be neglected thanks to the acceleration of the radial flow. These spillways operate so that the upstream flow is subcritical while the flow over the spillway itself becomes supercritical, creating a flow-control section above the crown. One characteristic of these structures is that, a short distance from the crown, the flow lines run nearly parallel.In this type of spillway, the crest is wide and substantial relative to the other dimensions. The crowns may be wide, horizontal, or follow a specific curvature. Although they can be used to measure discharge, they serve most often as dam spillways — and sometimes as the dam itself, when water is allowed to pass through — and can store large volumes of water when needed.Project DescriptionThis project investigates the flow inside a wide-edge spillway using ANSYS Fluent. There is a deliberate elevation difference between the main channel and the sub-channel, in part to store a portion of the flowing water. The RNG k-epsilon model solves the turbulent flow equations, while the multiphase VOF model captures the two phases of water and air within the open channel. Water enters the channel at a mass flow rate of 65 kg/s and passes into the second channel after striking the middle section of the spillway.Geometry & MeshThe geometry was created in ANSYS Design Modeler and meshed in ANSYS Meshing using a structured grid, for a total of 981,900 elements.MethodologySeveral key assumptions underpin the model. The simulation uses a pressure-based solver and is run as steady-state, so the results do not vary with time. Gravity is applied at −9.81 m/s² in the Y direction.Turbulence is modeled with the RNG k-epsilon model using standard wall functions, and the two phases — air as the primary phase and water as the secondary phase — are handled with the VOF approach. Water enters through a mass-flow inlet (65 kg/s) defined as an open-channel boundary, with a free-surface level of 0.08 m, a bottom level of 0 m, and density interpolation taken from the neighboring cell. The outlets are set as pressure outlets, and the walls are treated as stationary.For the solution methods, pressure–velocity coupling uses the SIMPLE scheme. Pressure is discretized with PRESTO! and momentum with second-order upwind, while volume fraction, turbulent kinetic energy, and turbulent dissipation rate all use first-order upwind. The solution is initialized with the standard method: gauge pressure 0 Pa, velocity 0 m/s, turbulent kinetic energy 1 m²/s², turbulent dissipation rate 1 m²/s³, and water volume fraction 0.ResultsThe water volume fraction contour shows that, because of the height difference and the absence of any inlet flow in the sub-channel, the water volume fraction takes nonzero values in the upper part of the sub-channel. Once the solution is complete, 3D contours of pressure, velocity, volume fractions, and related quantities are extracted and presented.

Spillway CFD SimulationDescriptionIn this project, a three-dimensional spillway is simulated using ANSYS Fluent to study how excess water is managed and released from a dam structure. Spillways serve as the outlet mechanism for a dam, designed to safely carry surplus water and floodwater from the reservoir side down to the downstream side once the water level rises past a defined threshold. Because agricultural water management relies heavily on dams and reservoirs for irrigation supply, understanding spillway hydraulics is directly relevant to agricultural and food engineering applications, where controlled water release protects both the structure and the farmland downstream.Several spillway designs exist, including ogee-shaped, stepped, side-channel, lotus, tunnel, and siphon spillways. This project focuses on simulating the flow behavior over one such spillway geometry using a multiphase approach, treating air as the primary phase and water as the secondary phase. In the model setup, the water column at the inlet reaches a height of 0.155 m, while the full model height is 0.306 m, and the dam structure itself has a height of 0.156 m.The three-dimensional geometry was built in Design Modeler, and the mesh was generated in ANSYS Meshing using an unstructured mesh strategy, resulting in a total of 698,691 elements.MethodologyThe two-phase air-water interaction is captured using the Volume of Fluid (VOF) multiphase model. Gravity is applied along the y-axis at a magnitude of -9.81 m/s² to correctly represent the driving force behind the water's downward flow over the spillway.ConclusionThe resulting flow contours confirm that the spillway performs as intended, allowing the water to pass over the structure smoothly. The highest flow velocities appear where the flow cross-section narrows, since the water accelerates as it's forced through the tighter geometry — a behavior consistent with what's expected in real spillway operation and useful for engineers designing water release systems for agricultural reservoirs.

Lifting Dam (Dam Break) — ANSYS Fluent CFD Simulation TrainingThis project presents a numerical simulation of a lifting dam (dam break) using ANSYS Fluent. The VOF (Volume of Fluid) model is used to capture the two fluid phases, with the goal of studying how the free surface of the fluid evolves over time. Two cases are examined: in the first, the flow continues freely after the dam is lifted, while in the second, it encounters an obstacle in its path.Geometry & MeshThe two-dimensional geometry was created in SpaceClaim, with a computational domain measuring 70 mm in length and 40 mm in height.Meshing was performed in ANSYS Meshing using an unstructured grid throughout. Case 1 contains 86,611 elements, while Case 2 contains 132,614 elements.MethodologySeveral assumptions underpin the model. Because the flow is incompressible, a pressure-based solver is selected, and the simulation is run as transient. Gravity is applied at −9.81 m/s² along the Y-axis. The two phases — air (density 1.225 kg/m³, viscosity 1.7894e-05 kg/m·s) and liquid water (density 998.2 kg/m³, viscosity 0.001003 kg/m·s) — are modeled with the Volume of Fluid approach using an explicit, sharp-interface formulation and implicit body forces.The laminar viscous model is used to solve the flow-field equations, with the SIMPLE scheme for pressure–velocity coupling. Momentum is discretized using second-order upwind, while pressure uses the PRESTO! scheme. The solution is initialized with the standard method, after which the water phase is patched into the initial region (volume fraction = 1). The calculation runs with adaptive time advancement over 2000 time steps at a step size of 0.0005 s.ResultsThe simulation tracks the free surface of the fluid as the dam is lifted. Once the solution is complete, contours of velocity, pressure, and volume fraction are extracted. In the second case, after the flow strikes the barrier it rises to a relatively high level, driven by the high kinetic energy present in the initial moments of the flow.

DescriptionThis project simulates the three-phase flow of water, air, and sand over a circular weir using ANSYS Fluent, investigated through CFD analysis. When an obstacle is placed in the path of a flow, it causes the fluid level to rise behind it and the velocity to increase, eventually leading the fluid to spill over the obstacle; structures of this kind are known as weirs. Weirs take various forms depending on their intended use and are widely employed in civil and agricultural water management — for controlling and measuring flow in irrigation channels, canals, and other water-conveyance systems central to agriculture.The model was built in 2D using SpaceClaim. Meshing was performed in ANSYS Meshing, producing 4,770 elements.MethodologyIn this simulation, water enters the computational domain at a velocity of 1 m/s and flows over a sand bed situated behind the weir. As it passes over the weir, the flow lifts some of the sand and carries it downstream.The standard k-epsilon model is used to solve the turbulent flow equations, while the Eulerian multiphase model is employed to capture the motion of and interaction between the three phases — water, air, and sand.ConclusionOn completion of the solution, two-dimensional contours of the volume fraction of the air, water, and sand phases, along with pressure, streamlines, and velocity vectors, were obtained.As the sand volume fraction contour shows, the water flow lifts a portion of the sand from the bed and transports it as it spills over the weir. Over the long term, the sand bed behind the weir is washed away entirely, and the emptied region behind the circular obstacle becomes a tangential path for the water — illustrating the sediment-transport and scouring behavior that is important when designing weirs for irrigation and agricultural water systems.