Premixed Combustion, Eddy Dissipation, ANSYS Fluent CFD Simulation TrainingDescriptionThis project simulates premixed combustion inside a combustion chamber using ANSYS Fluent, with fuel and air assumed to enter the chamber already premixed. The 2D geometry was designed in Design Modeler and meshed in ANSYS Meshing using a structured mesh totaling 86,002 elements.MethodologyThe Species Transport model is used to represent the combustion process, applying a single-step methane-air reaction with the volumetric option enabled to capture combustion throughout the chamber. Turbulence-chemistry interaction is handled using the Eddy Dissipation model, which bypasses detailed reaction kinetics and instead accounts for combustion behavior based purely on the effect of turbulent mixing. The energy equation is enabled to capture temperature changes driven by combustion, with turbulence modeled using the standard k-epsilon model.ConclusionThe simulation results include contours of temperature, velocity, mass fractions of the various species, and streamlines. The temperature contour shows a clear rise within the chamber, confirming that combustion has taken place. The streamlines also reveal secondary flow structures forming within the chamber — these secondary flows enhance the mixing between fuel and air, thereby improving the overall combustion process and offering insight into how flow structure directly influences combustion efficiency in premixed systems.

Premixed Combustion, Eddy Dissipation/Finite Rate Model, ANSYS Fluent CFD Simulation TrainingDescriptionThis project simulates premixed combustion inside a combustion chamber using ANSYS Fluent, with a particular focus on pollutant formation. The 2D geometry was designed in Design Modeler and meshed in ANSYS Meshing using a structured mesh totaling 86,002 elements.The Eddy Dissipation/Finite Rate model combines two distinct approaches to reaction rate calculation: the Eddy Dissipation model, which assumes combustion is limited purely by turbulent mixing, and the Finite Rate model, which calculates reaction rates directly from Arrhenius chemical kinetics. At each computational cell, the model takes the smaller of the two calculated rates — meaning the reaction proceeds at whichever rate is the limiting factor, mixing or chemistry. This makes the model particularly useful for cases like this one, where pollutant formation depends on capturing reaction kinetics accurately rather than assuming mixing is always the dominant limiting process, as the standalone Eddy Dissipation model does.MethodologyThe Species Transport model is used to represent the combustion process, applying a single-step methane-air reaction with the volumetric option enabled to capture combustion throughout the chamber. Turbulence-chemistry interaction is handled using the Eddy Dissipation/Finite Rate model, evaluating both the turbulent-mixing-limited rate and the kinetics-limited rate at each point in the domain and applying the smaller of the two — balancing mixing effects against reaction rates to more accurately capture pollutant formation mechanisms. The energy equation is enabled to capture temperature changes driven by combustion, with turbulence modeled using the standard k-epsilon model.ConclusionThe simulation results include contours of temperature, velocity, and mass fractions of the various species — including pollutant species — along with streamlines throughout the chamber. The temperature contour shows a clear rise within the chamber, confirming that combustion has taken place, while the species mass fraction results reveal where and how pollutants form as reaction byproducts.The streamlines also reveal secondary flow structures forming within the chamber, which enhance the mixing between fuel and air and directly influence both combustion completeness and pollutant formation. Because this model accounts for finite-rate kinetics alongside mixing, it can capture pollutant formation more accurately in regions where reaction rates are not purely mixing-controlled — offering insight directly applicable to designing cleaner combustion systems, optimizing existing combustion chambers for reduced emissions, and predicting pollutant formation in industrial combustion processes.

Non-Premixed Combustion, Eddy Dissipation, ANSYS Fluent CFD TrainingDescriptionThis project simulates non-premixed combustion inside a combustion chamber using ANSYS Fluent, with fuel and air entering the chamber through two separate boundaries — meeting and mixing only within the chamber itself, consistent with non-premixed combustion behavior. The 2D geometry was designed in Design Modeler and meshed in ANSYS Meshing using a structured mesh optimized for combustion simulation accuracy.MethodologyThe Species Transport model is used to represent the combustion process, applying a single-step methane-air reaction with the volumetric option enabled to capture combustion throughout the chamber. Turbulence-chemistry interaction is handled using the Eddy Dissipation model, which bypasses detailed reaction kinetics and instead accounts for combustion behavior based purely on the effect of turbulent mixing.The energy equation is enabled to capture temperature changes driven by combustion, with turbulence modeled using the standard k-epsilon model, and solver settings tuned to maintain stability and accuracy throughout the combustion simulation.ConclusionThe simulation results include contours of temperature, velocity, mass fractions of the various species, and streamlines. The temperature contour shows a clear rise within the chamber, confirming that combustion has taken place.The streamlines also reveal secondary flow structures forming within the chamber — these secondary flows enhance the mixing between fuel and air, thereby improving the overall combustion process. Together, these results demonstrate how the Eddy Dissipation model captures non-premixed combustion behavior in a way directly applicable to real-world industrial combustion chamber design and analysis.

DescriptionThis project uses ANSYS Fluent to simulate multi-jet ethylene-air combustion, applying species transport and reacting flow modeling to a core problem in chemical reaction flow engineering. The simulation examines how multiple angled jets mix and react, capturing the interaction between turbulent flow, species transport, and chemical reaction — relevant to combustion systems across aerospace propulsion, gas turbines, and industrial furnaces.MethodologyA 2D combustion chamber geometry with multiple jet inlets is built in DesignModeler and meshed in ANSYS Meshing using a structured grid of 9,928 elements. The simulation uses a pressure-based, steady-state solver, with the Species Transport model configured for volumetric reactions to represent ethylene-air combustion, and the Eddy-Dissipation model applied to capture turbulence-chemistry interaction.ConclusionResults include pressure, velocity, and temperature contours, along with species concentration distributions showing combustion product formation. The simulation reveals how jet velocity and angle affect mixing and combustion behavior, temperature distributions and peak combustion zones, and the formation of combustion products relevant to emissions. These findings support combustor design optimization for improved combustion efficiency and reduced emissions across aerospace, power generation, and industrial thermal systems.

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.

Combustion Inside the Boiler, ANSYS Fluent CFD Simulation TrainingDescriptionThis project simulates combustion inside a boiler using ANSYS Fluent. The 3D geometry was designed in SpaceClaim, with airflow entering through the boiler's side panel and a combination of fuel streams entering through narrow pipes at the boiler's lower section, while the outlet connects to the upper pipe. The domain was meshed in ANSYS Meshing, totaling 4,694,637 elements.MethodologyBoilers are pressurized tanks designed to boil or heat a working fluid, raising its temperature to the boiling point — a process that depends on sustaining a combustion reaction within the boiler itself. This combustion reaction occurs throughout the boiler's computational domain, with the relevant chemical species defined using the Species Transport model. Nine distinct species were defined to represent the combustion chemistry, governed by five volumetric combustion reactions between them.The boiler features two inlets: an airflow inlet entering from the side at 303.15 K with a mass flow rate of 3.375 kg/s, and a fuel inlet — a combination of several different fuel species — entering through the lower narrow pipes at 300 K with a mass flow rate of 0.6135 kg/s. Turbulence was resolved using the Realizable k-epsilon model, with the energy equation enabled to capture temperature variation throughout the domain as combustion progresses.ConclusionResults include 2D and 3D contours of temperature, velocity, and mass fraction for each defined species, including oxygen, carbon dioxide, water vapor, CH₄, C₂H₄, C₃H₄, and C₄H₁₀. The results show that as the hydrocarbon fuel species combine with oxygen, a combustion reaction takes place, driving a clear rise in temperature throughout the boiler's interior.As this reaction proceeds, hydrocarbon and oxidant concentrations decline near the boiler's inlet region, while carbon dioxide and water vapor — the primary combustion products — correspondingly increase in concentration, confirming that the fuel-oxidizer mixture is being consumed and converted into combustion products as expected throughout the boiler.

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.

DescriptionThis project simulates the combustion reaction — fire and smoke — arising from a leaking pressure tank in a factory using ANSYS Fluent. The factory is modeled as a computational domain containing several elements such as tanks, plates, and boxes. A cylindrical pressurized tank develops a leak, releasing flammable methane gas into the surrounding environment; the contact of this methane with the free ambient air then leads to a combustion reaction.The aim of the project is to investigate the behavior of the combustion flame and the path of smoke emission over time, so the simulation is carried out in a time-dependent (transient) manner.The study proceeds in two steps. The first step examines only the leakage of methane from inside the tank into the surrounding space, with methane released gradually over time. The second step allows this leaked gas to react with the air and ignite, producing flame and smoke (carbon dioxide) through the combustion reaction. In the first step there is no need to define a chemical reaction — only air and methane are present, without reaction. Both the factory air and the methane inside the tank are under pressure; a groove at the top of the tank serves as the leakage point, and assigning a higher initial pressure to the methane drives its release into the outer environment. Once the release has fully developed, the combustion reaction between methane and the free air is defined using stoichiometric coefficients, with methane and oxygen as reactants and carbon dioxide and water vapor as products. A spark is also defined at the groove section of the tank to initiate combustion.The geometry was created as a 3D model in Design Modeler, and meshing was performed in ANSYS Meshing using an unstructured grid of 124,162 cells.MethodologyThe viscous model used is RNG k-epsilon with standard wall functions. The solver is transient, and the energy equation is enabled to capture the temperature field. The Species Transport model is used to simulate the combustion reaction.ConclusionAfter the simulation, the behavior of the reactants and reaction products was examined. To study the flame, an iso-surface at a constant temperature was used, with the flame temperature taken as the measure representing the flame's extent. To investigate the smoke produced by combustion, the behavior of carbon dioxide — defined as a product of the reaction — was examined, using its mass fraction as the iso-surface measure. Similarly, the leaked methane was tracked using its mass fraction as an iso-surface measure. Methane leakage before combustion, and the flame and carbon dioxide emission after combustion, were all studied at different time instants and presented as animations.In the first step, the results clearly capture the leakage process: methane first fills the pressurized tank, then, once the leak occurs, escapes into the surrounding environment at high pressure. In the second step, the results show the onset of the combustion reaction. The temperature rises sharply as a result of the explosion; the flame grows at the start of combustion and then gradually fades over time. Carbon dioxide is produced throughout the space, confirming that combustion has taken place, since this gas is the product of the reaction — it too erupts at the moment of ignition and diminishes in volume as time progresses.

DescriptionThis project simulates combustion in the presence of an electrohydrodynamic (EHD) field using ANSYS Fluent. A simple combustion chamber is designed, into which airflow and fuel enter axially. The fuel, C₁₀H₂₂ (decane), enters through the central section, with the airflow surrounding it.The study is carried out in two stages. First, ordinary combustion between air and fuel is investigated; then the same combustion is performed in the presence of an EHD field. Applying EHD causes the fluid to become electrically charged, and the motion of the ionized particles or molecules — together with their interaction with the electric field and the surrounding fluid — is studied. The combustion reaction is modeled using the Species Transport model, with C₁₀H₂₂ and O₂ defined as reactants and CO₂ and H₂O as products.Airflow enters the chamber at 447 K with a velocity of 5 m/s, while fuel enters at 300 K with a velocity of 0.01 m/s. The EHD model is used to impose the effect of the electric field on the chamber's performance: a current density of 40 A/m² is applied at the inlet and outlet boundaries, with a positive charge defined on the inlet boundary and a negative charge on the outlet boundary.Geometry & MeshThe geometry was created as a 3D model in Design Modeler. The computational domain is a horizontal cylindrical combustion chamber; fuel enters through a narrow inner tube, and airflow enters around this tube. Meshing was performed in ANSYS Meshing using an unstructured grid, producing 1,000,658 cells.Setup & SolutionSeveral assumptions underpin the simulation: a pressure-based solver is used, the simulation is steady, and the effect of gravity is neglected.Viscous model — standard k-epsilon with standard wall functionsSpecies — Species Transport with 5 volumetric species (C₁₀H₂₂, O₂, CO₂, H₂O, N₂) and volumetric reactionsEnergy — enabledPotential (electric field) — enabledBoundary conditions — Inlet-Air: velocity inlet at 5 m/s, 447 K, O₂ mass fraction 0.21, current density −40 A/m²; Inlet-Fuel: velocity inlet at 0.01 m/s, 300 K, C₁₀H₂₂ mass fraction 1, current density 0 A/m²; Outlet: pressure outlet at 0 Pa gauge, current density 40 A/m²; Inner Wall: stationary, coupled thermal condition; Outer Wall: stationary, zero heat flux, current density 0 A/m²Methods — Coupled pressure-velocity coupling; second-order for pressure; second-order upwind for momentum, species mass fraction, and energy; first-order upwind for turbulent kinetic energy and turbulent dissipation rateInitialization — standard method, with 0 Pa gauge pressure, O₂ mass fraction 0.21, velocity 5 m/s, temperature 447 K, and potential 0ConclusionOn completion of the solution, 2D and 3D contours of temperature, velocity, pressure, and the mass fraction of each species (CO₂, C₁₀H₂₂, O₂, N₂, and H₂O) were obtained. These results are presented in two modes — without EHD and with EHD — so that the effect of the electric field can be assessed through direct comparison.The contours show that when EHD is applied to the combustion chamber, more energy is delivered to the species, producing higher product temperatures. This rise in the temperature of the reacting species accelerates the combustion reaction. Furthermore, examination of the reaction products indicates that combustion in the presence of EHD proceeds with higher quality, demonstrating how the electric field can be used to enhance combustion performance.

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.