Non-Premixed Combustion — ANSYS Fluent CFD SimulationDescriptionThis project simulates non-premixed combustion in a 2D combustion chamber, where air and hydrocarbon fuel enter through two separate inlets and react to release the fuel's chemical energy as heat. It's a foundational study in reacting-flow CFD — the configuration that describes most real burners, furnaces, and gas-turbine combustors, where fuel and oxidizer are deliberately kept apart until they meet in the reaction zone. Within the Combustion: Beginner CFD Training Package, this project introduces the foundational combustion model — the mixture-fraction approach — establishing the core reacting-flow method the later chamber, swirl, and flare cases build on.MethodologyThe key modeling choice is the non-premixed (mixture-fraction) approach within Fluent's Species Transport framework. Instead of tracking every reaction rate directly, the model solves transport equations for the mixture fraction — the local mass fraction originating from the fuel stream — and reads the resulting species and temperatures from pre-computed chemistry. This is what makes non-premixed combustion both efficient and stable: the chemistry is folded into the mixture fraction, so you model the mixing and let the thermochemistry follow. By definition, the fuel and oxidizer enter through independent paths and do not premix before reaching the chamber. An air stream (N₂ at mass fraction 0.767, O₂ at 0.233) enters at 300 K and 1.19 kg/s, while a pure CH₄ (methane) stream enters at 300 K and 0.019 kg/s through a separate inlet. The geometry is built in Design Modeler and meshed in ANSYS Meshing as an unstructured mesh of 11,202 cells.AnalysisThe results provide contours of pressure, temperature, velocity, and density, plus mass-fraction fields for O₂, CH₄, H₂O, CO₂, N₂, CO, and C₂H₆, along with in-chamber pathlines. The fields confirm a properly anchored combustion reaction: methane and air react where the streams meet, consuming reactants and producing CO₂, H₂O, and intermediates like CO — and the temperature field maps the flame and hot-product zone exactly where the mixture fraction is near stoichiometric. By the end of this project, you'll be able to set up Species Transport with the non-premixed mixture-fraction model, define separate fuel and oxidizer inlets with realistic compositions and flow rates, and read flame structure and product formation from temperature and species contours.

Combustion Chamber (Transient) — ANSYS Fluent CFD SimulationDescriptionThis project simulates a combustion chamber in ANSYS Fluent using a transient, pressure-based solver with the effect of gravity included. Combustion is the central theme: methane is burned with air inside the chamber, and the simulation is built around capturing the chemical reaction, the resulting heat release, and the way the hot products move through the geometry. The chamber comprises three main parts — the air inlet pipe, the burner section, and the outlet pipe — and contains a thin internal wall pierced by cavities of varying size. The small primary holes cool the chamber wall through a layering film of flow, while the larger holes help anchor the flame in the center of the chamber, a configuration typical of real combustor liners. Within the Combustion: Beginner CFD Training Package, this project adds time-dependence to the combustion-chamber progression, building on the steady-state chamber toward transient flame behavior in a realistic combustor geometry.MethodologyThe geometry is three-dimensional and was created in Design Modeler, then meshed in ANSYS Meshing using an unstructured triangular grid of 694,928 elements. Because the flow inside a combustor is complex and highly turbulent, the RNG k-ε turbulence model with standard wall functions is used. Combustion itself is represented through the Species Transport model, which is the heart of the setup: it tracks each chemical constituent and the reactions that convert reactants into products while releasing energy. Air and fuel (CH₄) enter at mass flow rates of 0.02 kg/s and 0.0006 kg/s respectively, both at 300 K, and the chamber's outer wall is treated as adiabatic. The reaction is modeled as a two-step methane–air combustion involving six species — methane, oxygen, nitrogen, water vapor, carbon dioxide, and carbon monoxide — with the inlet air composed of oxygen and nitrogen at mass fractions of 0.23 and 0.77.AnalysisThe results are presented as three-dimensional volume renderings and streamlines of velocity, pressure, temperature, density, and the mass fractions of the participating species, giving a detailed view of the combustion process. Air enters around the periphery and the methane–air mixture from the bottom surface, meeting to form the combustion region. There, temperature and pressure rise sharply as the reaction proceeds, and the heated flow accelerates toward the outlet — the central behavior the simulation sets out to capture. By the end of this project, you'll be able to set up a transient Species Transport combustion simulation with a multi-step methane–air reaction, model a realistic combustor liner with film-cooling and flame-anchoring holes, and interpret the temperature, pressure, and species fields that reveal flame stabilization, heat release, and the transport of combustion products.

Vortex Combustion Chamber Simulation in ANSYS FluentIntroductionThis project simulates the combustion reaction occurring inside a vortex combustion chamber using ANSYS Fluent. Combustion is a chemical process between a combustible material and an oxidizing agent, resulting in the release of heat and the transformation of raw materials, typically accompanied by light in the form of a flame or glow. While combustion is fundamentally a form of oxidation reaction, its rapid reaction rate, substantial heat release, and associated temperature rise and flame formation place it in a distinct category of chemical processes. The vortex combustion chamber represents a new generation of liquid-fuel internal combustion engine design, in which a specific injector arrangement generates a swirling vortex flow. This vortex enhances cooling and improves mixing of the propulsion components within the chamber, enabling complete combustion to be achieved in a smaller chamber volume.Geometry and MeshThe combustion chamber geometry was designed and meshed within GAMBIT, using an unstructured mesh totaling 379,535 cells.MethodologyThe combustion process was analyzed using the species transport model, with a mixture of air and methane serving as the fuel. The Eddy-Dissipation method was employed to capture the chemical-turbulent interaction of the combustion reactants, and the NOx prediction model was activated, using the temperature method for the turbulence-chemistry interaction mode. The ideal gas equation was used to account for density variations resulting from temperature changes within the chamber.Results and ConclusionContours of velocity, pressure, temperature, and species mass fraction were generated in both 3D and 2D, clearly capturing the formation of the combustion flame and the resulting temperature distribution within the chamber. Velocity vectors reveal a high degree of flow turbulence throughout the domain, and the overall contour results confirm that the combustion chamber's performance has been accurately captured by the simulation.

DescriptionThis project investigates non-premixed hydrogen–air combustion in a lab-to-semi-industrial-scale furnace, with a particular focus on how the accuracy of viscosity and thermal-conductivity modeling affects predicted flame behavior. Rather than relying on default property models, the simulation pairs Sutherland's law for viscosity with kinetic-theory-based thermal conductivity, since correctly capturing these fluid properties is central to how well turbulence and chemistry couple in a reacting flow. The furnace geometry has separate fuel and air inlets: air enters at 0.01 kg/s and hydrogen at 0.0003 kg/s, giving a stoichiometric mixture (equivalence ratio of 1), with the fuel inlet centered 0.25 m from the furnace floor and nested within the air inlet. The outlet is set to atmospheric pressure, and the side walls lose heat to the surroundings by convection and radiation through a 5 cm steel shell, with a heat transfer coefficient of 16 W/m²K, an ambient temperature of 300 K, and a sky temperature of 271.2 K.MethodologyThe domain is discretized with a structured mesh built in ANSYS Meshing, and the non-premixed air/hydrogen mixture is handled through the Species Transport model. Turbulence is closed with the standard k–ε model, while the combustion itself is resolved through the eddy dissipation approach, with energy source diffusion and turbulence–chemistry interaction both active; this method assumes species conversion is fast relative to turbulent mixing, which holds well for atmospheric-pressure reactions in an open furnace geometry. Pressure–velocity coupling uses the SIMPLE algorithm, gradients are discretized with Least Squares Cell-Based, pressure with Second Order, and all other variables with Second Order Upwind, with under-relaxation tuned to bring the solution to convergence.AnalysisThe centerline results at the fuel inlet show a peak velocity of 1063 m/s and a peak temperature of 1860 K, with H2 mass fraction dropping to zero by the facing surface and H2O mass fraction rising from zero to a steady 0.23 after about 0.3 m. The reaction rate peaks at 0.23 kmol/m³/s just 2 cm from the inlet and falls to zero by 0.4 m, marking where the flame effectively completes. Volumetric temperature contours show a furnace-wide maximum of 2102.56 K, with higher average temperatures concentrated in the lower furnace, while isotherm planes spaced 0.125 m apart confirm a peak of 2080 K. Velocity is presented both at full scale and capped at 100 m/s to expose lower-speed flow structures that would otherwise be masked, and mass fraction contours on the furnace's symmetry plane trace how combustion species distribute through the chamber. Eddy viscosity fields illustrate the turbulent kinetic energy cascading into internal energy, tying the flow's turbulent structure directly to the high-temperature zones identified elsewhere in the results. Taken together, the results indicate that the eddy dissipation method, combined with the Sutherland/kinetic-theory property treatment, reproduces the expected physics of a fast, mixing-limited combustion process with good fidelity across velocity, temperature, species, and reaction-rate fields.

DescriptionThis project investigates combustion inside an industrial biomass waste incinerator using ANSYS Fluent, with the goal of understanding how fluid flow, heat transfer, and chemical reactions interact to produce uniform combustion across the waste surface, a key factor in waste-to-energy efficiency. The geometry includes a trapezoidal waste pile, multiple air and fuel inlets, two exhaust gas outlets, and a cooling system, built in Design Modeler and meshed in ANSYS Meshing with 513,233 elements.MethodologyThe simulation runs steady-state with a pressure-based solver, using the Realizable k-epsilon model with standard wall functions to resolve the complex flow patterns inside the incinerator. The energy equation is enabled to capture the thermal behavior driving and resulting from combustion. Chemistry is represented through the Species Transport model, defining two primary reactions, CH4 + O2 and H2 + O2, with the eddy-dissipation model handling turbulence-chemistry interaction under the fast-chemistry assumption typical of industrial combustion. Since the waste itself continuously generates combustible gases as it burns, fixed source terms for CO and H2 mass fraction are applied directly at the rubbish surface boundary to represent this ongoing gas release.AnalysisThe results show a strong temperature gradient through the incinerator, rising from a 300 K inlet to an average zone temperature of 2619.4 K and an outlet chamber temperature of 4042.636 K, confirming substantial heat generation in the main combustion region. Velocity contours reveal complex internal flow patterns reaching up to 33.25 m/s, which govern how effectively air and fuel mix and how heat distributes through the chamber. Static temperature contours show peaks above 4000 K in the core combustion zone, with the waste surface itself showing higher temperatures near the fuel inlets and in areas of stronger air-fuel mixing. CH4 and CO2 mass fraction contours trace the reaction's progress directly, with CH4 concentrated near the fuel inlets and CO2 building up downstream in the post-combustion zones, while temperature-colored pathlines show recirculation zones forming as air and fuel streams interact, which enhances mixing and helps drive more complete combustion. Together these results indicate the current inlet layout achieves good overall combustion performance, though adjusting inlet positions and flow rates could further even out the temperature distribution across the waste surface, a change that would likely improve combustion efficiency and reduce emissions.

Hypersonic Combustion in Scramjet with Viscous Heating, CFD Simulation ANSYS Fluent TrainingDescriptionHydrogen combustion inside a scramjet engine at hypersonic speed represents one of the most demanding reacting-flow problems in CFD, coupling supersonic compressible flow, finite-rate chemistry, and wall heating within a single transient case.A scramjet (supersonic-combustion ramjet) has no moving parts — it relies entirely on engine geometry to compress incoming air, inject and burn fuel, and expand the combustion products for thrust. This distinguishes it from a conventional ramjet, which decelerates flow to subsonic conditions before combustion occurs; a scramjet instead sustains supersonic combustion throughout, enabling flight above Mach 5.The 2D geometry consists of two sections — a lower preheating region and an upper stable-burn region — built in Design Modeler and meshed in ANSYS Meshing using a structured grid of 16,320 cells. Inlet air enters at Mach 6, with the domain initialized at 300 K. At the mid-nozzle location, where the flow decelerates to Mach 1, hydrogen is injected supersonically, triggering combustion within the nozzle.MethodologyCombustion is modeled using the Species Transport model with its volumetric reaction sub-model, with air treated as an ideal gas so that density responds correctly to the steep temperature rise generated during burning. Turbulence is captured using the standard k-ε model, and the case is solved as transient to resolve the developing flow field and flame structure.Given the numerically stiff nature of hypersonic reacting flows, first-order discretization schemes and reduced under-relaxation factors are deliberately applied to maintain stable convergence throughout the solution process.ConclusionResults include 2D contours and vector fields for pressure, temperature, velocity, Mach number, density, and turbulence intensity. The flow physics follows a clear progression: air enters the domain, decelerates to Mach 1 at the combustion section, then re-accelerates toward the outlet. Combustion drives temperatures beyond 4000 K, with viscous heating clearly visible in the near-wall elements, where high-speed shear converts kinetic energy into heat at the wall surface.

DescriptionExplosions in oil storage tank farms represent a persistent safety hazard in reacting flow modeling, where a rapid, energetic chemical reaction consumes fuel and releases heat along with multiple gaseous combustion products into the surrounding environment. This CFD study uses ANSYS Fluent to simulate the explosion of oil storage tanks and the subsequent dispersion of combustion pollutants across an urban area, addressing a real safety concern for regions where tank farms sit close to residential neighborhoods and industrial units. The analysis evaluates how far and in what concentrations explosion-generated pollutants such as carbon dioxide and other combustion gases reach the surrounding population, providing a basis for risk assessment and emergency planning.MethodologyThe three-dimensional urban domain, measuring 6.6 km in length, 4.6 km in width, and 200 m in height, is built in Design Modeler and includes a dedicated zone containing eighteen cylindrical oil tanks alongside separate zones representing residential and industrial districts. The domain is discretized with an unstructured mesh of 1,746,979 elements. Because the explosion involves chemical reactions among several gaseous constituents, the Species Transport model forms the core of the setup, tracking seven species — CO₂, SO₂, NO₂, CO, H₂O, C, and air, with air serving as the background fluid. The explosion is represented through defined energy and mass sources within the tank region: a heat source of 139,072.7 W/m paired with production rates for each pollutant, including CO₂ at 0.1358 kg/m³·s, H₂O at 0.0679 kg/m³·s, CO at 0.0047 kg/m³·s, SO₂ at 0.000131 kg/m³·s, C at 0.0068 kg/m³·s, and a small NO₂ contribution. Wind-driven dispersion is captured by setting the northern and western domain faces as airflow inlets and the eastern and southern faces as outlets, with air entering at 300 K and 20 m/s directed at a 60° angle, decomposed into corresponding x- and y-velocity components.Results AnalysisThe simulation produces three-dimensional contours of temperature and of the volume fraction for each gaseous species throughout the domain. Results show that the released pollutants are carried by wind into the surrounding residential and industrial zones, confirming potential population exposure following such an explosion event. The study demonstrates how species transport combined with defined energy and mass sources can reproduce the generation and atmospheric spread of combustion products, offering a practical basis for evaluating explosion hazards and informing the siting, spacing, and protection of facilities located near populated areas.

Pollution Ventilation in a Subway — DescriptionThis project simulates pollution ventilation in a subway station using ANSYS Fluent, with a focus on the station's air-conditioning system. A subway station is one of the busiest of public spaces and is therefore readily exposed to pollution. In this model, a polluting gas is defined with a molecular weight of 77.5 kg/kmol and a specific heat capacity of 1100 J/kg·K.The subway doors are treated as the sources of pollutant, since they are the points where passengers gather. The air-conditioning system is positioned on the ceiling of the station and uses its suction power to draw pollutants out into the surrounding environment. The pollutant gas enters the station at a velocity of 0.1 m/s and is carried outside by the vacuum pressure.The Species Transport model is used for the simulation, with two species defined — the air already present inside the station and the pollutant gas that enters it. The model solves the transport equations for each species. The suction at the ceiling outlet panels is defined using the Exhaust Fan boundary condition, in which a pressure jump draws the pollutant gas out of the environment. This pressure jump is set to 1,000,000 Pa.Geometry & MeshThe geometry was drawn in Design Modeler and represents a subway station comprising a subway line with rails.Setup & SolutionViscous model — RNG k-epsilon with standard wall functionsSpecies — Species Transport with 2 volumetric species (air and pollutant gas)Energy — enabledBoundary conditions — Inlet-Doors: velocity inlet at 0.1 m/s, 300 K, pollutant mass fraction 1; Inlet-Subway: pressure inlet at 0 Pa gauge, 300 K, pollutant mass fraction 0; Outlet-Panels: exhaust fan at 0 Pa gauge with a 1,000,000 Pa pressure jump; Walls: stationary, with zero heat fluxMethods — SIMPLE pressure-velocity coupling; second-order discretization for pressure; first-order upwind for momentum, turbulent kinetic energy, turbulent dissipation rate, pollutant, and energyInitialization — standard method, with an initial velocity of 0 m/s, temperature of 300 K, and pollutant mass fraction of 0ConclusionOn completion of the solution, 3D contours of pressure, velocity, and pollutant mass fraction were obtained. The pollutant contour indicates that the station's air-conditioning system performs effectively: although pollutants enter through the subway doors, they do not spread into the station space. The powerful ceiling-mounted fans of the air-conditioning system draw the contaminated air out to the external environment, keeping the station interior clear — demonstrating the role of the exhaust fan in maintaining air quality within the station.

DescriptionIn tunnel ventilation, longitudinal ventilation is the approach that offers the lowest installation and operating cost. The most common method uses jet fans, whose relatively high-velocity discharge induces airflow along the tunnel. As the air leaving the fan diffuses, it transfers energy to the tunnel airflow and raises the static pressure. Exhaust ducts then remove the hot gases and smoke produced by vehicles and by any fire from the tunnel volume; in some cases the extraction capacity may limit the longitudinal velocity in the tunnel during normal operation. Every tunnel ventilation system relies on tunnel jet fans, large axial fans, or a combination of the two to provide both pollution-control ventilation and smoke ventilation during a tunnel fire.This project presents a 3D simulation of a tunnel in which several cars are moving. Hot gases are emitted from the vehicle exhausts, and three pairs of fans mounted at the top of the tunnel extract the pollution by suction. By driving a flow in the direction of the fans, the pollutant — which rises because it is less dense than air — is carried out of the tunnel.Geometry & MeshThe domain is a 3D rectangular tunnel measuring 60 m in the X direction, 10 m in Y, and 9 m in Z. Four cars are positioned at different locations along the tunnel, and three pairs of fans are mounted on the ceiling, spaced 25 m apart. The geometry was created in SpaceClaim, and meshing was performed in ANSYS Meshing using tetrahedral elements. After importing the mesh into Fluent, the elements were converted to polyhedral, which significantly reduced their number to approximately 1,200,000.MethodologySeveral assumptions underpin the simulation: a pressure-based solver is used, the energy equation is enabled, the model is steady, and the effect of gravity is included. The jet fans are the core of the setup — they establish the longitudinal airflow that drives the smoke and pollutants toward the extraction points and out of the tunnel.ConclusionOn completion of the solution, two-dimensional contours of pressure, velocity, and the volume fractions of pollution and air were obtained, with the contours captured at every fifth iteration. The static pressure can be seen varying across different parts of the tunnel as a result of the fan action, and the streamlines trace the pollution leaving the vehicle exhausts and following its exact path toward and through the fans. Overall, the simulation demonstrates how a jet-fan longitudinal ventilation system establishes the airflow needed to control smoke and pollutants along a tunnel — the central function of the fans in maintaining safe tunnel conditions.

DescriptionThis project simulates cigarette smoke dispersion inside a smoking room using ANSYS Fluent, with an exhaust fan mounted on the upper wall and six air intakes at the base of the walls that draw in air due to the resulting negative room pressure. The room contains three occupants: a smoking woman seated on a bench near the domain's center, positioned relatively close to the exhaust fan's direction, a standing woman holding a cigarette in front of her, and a non-smoking man conversing with them nearby. The goal is to understand how air vortices shape smoke distribution in different parts of the room, which in turn informs where seating like a couch or bench should ideally be placed. The 3D geometry is built in Design Modeler and meshed in Fluent Meshing with a polyhedral grid of 965,187 elements.MethodologyCigarette smoke, treated as composed of four constituent materials, is modeled using both the Species Transport model and the Discrete Phase Model (DPM) together, capturing both the gas-phase dispersion and the discrete particulate behavior of the smoke. The exhaust fan on the ceiling is set to a negative pressure of -10 Pa to drive the room's ventilation, the energy equation is active to resolve temperature, and turbulence is handled with the standard k-epsilon model.AnalysisThe solution yields 2D and 3D contours of temperature, pressure, velocity, and smoke mass fraction, with 2D contours extracted on YZ and XZ planes through the room's center, along with time-resolved smoke pathlines. These pathlines show clearly how the combined intake and exhaust airflow shapes the smoke's movement through the room. The results indicate that seating placed closer to the exhaust fan's direction experiences a lower likelihood of air vortex formation, making that positioning preferable for reducing smoke exposure at seated locations. It's worth noting that smoke in this simulation originates only from the cigarette tips themselves; smoke inhaled and re-exhaled by occupants is not modeled, even though it could be a meaningful contributor to smoke distribution in real occupied spaces.