CFD Simulation of Reacting Flows and Combustion: Engine and Gas Turbine
Knowledge of the underlying combustion chemistry and physics enables designers of gas turbines, boilers and internal combustion engines to increase energy efficiency and fuel flexibility, while reducing emissions.
Combustion System couples multiphysics simulations incorporating accurate physical models with an advanced chemistry solver to provide a complete end-to-end combustion chemistry simulation capability to optimize products that involve reacting flow. By using Accurate reaction mechanisms that representing every class of reaction important for combustion analysis and combination of advanced computational fluid dynamics (CFD) combustion simulation tools such as Kiva, Ansys Fluent, Ansys Forte, AVL Fire, Converge CFD, Siemens Star-ccm+ and System Modeling software such as Matlab Simulink and GT-Suite enable Esimlab engineering team to reduce chemistry analysis time by orders of magnitude, virtually eliminating the bottleneck that chemistry integration produces during the simulation process. Faster time to solution makes it possible to spend more effort exploring design alternatives, conducting experiments, understanding where and why problems occur, and explaining observations without sacrificing accuracy.
Spray and Turbulence
Accurate spray and turbulence modeling is critical for predictive diesel and gasoline combustion simulations. In order to obtain results that are as realistic as possible, we use a wide variety of spray and turbulence modeling such as Reynolds-Averaged Navier-Stokes (RANS) and Large Eddy Simulation (LES) turbulence models.
For spray, simulate injection, breakup, vaporization, and other spray-related processes with detail are available. We can perform simulations that are dual fuel or multi-fuel and diesel and gasoline are not the only fuels that we can simulate.
Becasue of deep concern to engine manufacturers are the constantly evolving emissions regulations, To help meet these regulations, we simulate soot and NOx via its detailed chemistry. Soot emissions from gas turbine combustors are increasingly becoming a critical design factor as new particulate matter emissions regulations.
internal combustion (IC) enginesSimulating internal combustion (IC) engines is challenging due to the complexity of the geometry, spatially and temporally varying conditions, and complex combustion chemistry in the engine. In a complex IC engine case, mesh resolution requirements to capture relevant flow features can vary significantly in time and space. This is a challenge that Adaptive Mesh Refinement can easily solve.
Esimlab engineering Combustion Simulation Service include:
Gas Turbine Combustion CFD Simulation: AVL Fire, Siemens Star-ccm+, Ansys Fluent and Converge
Gas turbine combustion can be a challenge to achieve accurate and reliable CFD simulation results. Computational efficiency requires appropriate mesh resolution and turbulence, spray, combustion, and emissions models that provide an appropriate level of detail. With using advanced and specilized CFD tools such as AVL Fire, Siemens Star-ccm+, Ansys Fluent and Converge, Esimlab engineers can accurately predict important kinetically limited gas turbine phenomena such as ignition, flashback, and lean blow off. In addition, we can investigate the combined effects of chemistry and turbulence and optimize combustor performance parameters.
EsimLab Simulatin service for gas turbine combustion include:
- Modeling of ignition and flame propagation with representation of the spark energy, volume, duration, and flame kernel formation and propagation
- Spark modeling, combined with detailed chemistry
- Effect of fuel/air ratio and burner spacing on relight propagation time
- Simulating Lean blow off (LBO) including both gaseous and liquid fuels and maximize combustor performance factor for lean premixed systems to reducing flame temperatures and thus inhibiting NOx formation
- Simulation Flashback ( flamespeed of the fuel can overcome the flow velocity and flashback occurs and flashbakc ocuurs) of premixed fuel/air systems to invetsigate probabilityof damage to equipment.
- Spray modeling of liquid fuel simulations of gas turbines including all steps of the spray process, including primary and secondary breakup, filming, splashing, coalescence, and collision.
- Simulation of emissions of pollutants such as NOx, CO, and soot as a design parameters for gas turbines
- Coupled combustion – CHT (conjugate heat transfer) simulation to predict combustor wall temperatures which captures flame shapes, cooling flows, and metal thermal conditions
Fuel Injectors and Spray CFD Simulation
CFD software such as AVL Fire, Siemens Star-ccm+, Ansys Fluent and Converge is well equipped to simulate fuel injectors and spray processes including liquid atomization, drop breakup, collision and coalescence, turbulent dispersion, spray cavitation, drop-wall interaction, and drop evaporation.
Wide array of fuel injection simulation methodology, and robust and well-validated physical models allow us for accurate and computationally efficient simulation of these complex physical processes. In applications such as internal combustion engines, the fuel spray initiates, propagates, and dissipates very quickly on a very small spatial scale. The combustion process can be strongly affected by the exact nature of the fuel spray: droplet velocity, size, distribution, and physical attributes and for dynamically capture the important physics of the injection process, we need a high-density grid around the spray.
Esimlab engineering team use advanced CFD tools for simulation and analysis of the injection of liquid fuel via physical models for blob injection, injection distribution, variable rate-shape, discharge coefficient, and hollow cone and solid cone sprays and simulating the mixing and evaporation of multi-component fuel sprays.
Aftertreatment systems are a critical component to ensure emissions from engines and power generation equipment comply with environmental standards. CFD (computational fluid dynamics) simulations can be used as part of a rapid prototyping process to design systems that reduce NOx, CO, and particulate matter emissions with minimal efficiency and maintenance costs. Two of the main challenges in aftertreatment system design are maximizing the uniformity of flows upstream of catalysts and eliminating areas at risk for urea deposition.
- transient simulations for predict the uniformity of and velocity upstream of catalysts.
- change the mixer locations or pipe configurations and invetstigate its effect on performance.
- detailed NOx reduction and NH3 slip analysis with using coupled 1D surface chemistry tools such as GT-SUITE and advanced 3D CFD (computational fluid dynamics) simulation software for complex chemistry analysis inside the SCR catalyst brick.
- Identifying where and when urea deposits will occur requires
- Simulation of the spray-wall interaction, filming and wall cooling to indicate which films are at risk for urea deposit formation
Conjugate Heat Transfer for Predictive Fluid-Solid Heat Transfer
We simulate fluid flow and assume that the walls of the container were at a constant temperature or even adiabatic. In reality, however, there may be significant heat transfer between the fluid and its container, and thus our CFD simulation must be include this phenomenon. The internal combustion engine is one example of such an application. Using (CFD) combustion simulation tools such as Kiva, Ansys Fluent, Ansys Forte, AVL Fire, Converge, Siemens Star-ccm+ and System Modeling software such as Matlab Simulink and GT-Suite and FEA tools Such as Abaqus and Nastran enable Esimlab engineering team for real world simulation of such complicated engineering problem with innovative use of computational tools and programming to add special ability into this softwares.
The internal combustion engine industry is moving toward simulating the entire system rather than independent components. Conjugate heat transfer (CHT)—the simultaneous prediction of heat transfer in both the fluid and solid portions of the domain—is of critical importance in a full-engine simulation. The accuracy of the predicted combustion in the cylinder is dependent on the temperature boundary conditions in the cylinder. By considering heat transfer in the metal components (e.g., the cylinder head, liner, piston, etc.) in the simulation, the cylinder wall no longer has a user-specified temperature, but instead has temperatures predicted as part of the system simulation.
1D/3D-coupled analyses and Co-Simulation
Esimlab engineering team use advantage of CFD solver’s detailed chemistry, multiphase flow modeling, and other powerful features in coupling and co-simulation of CFD (Siemens Star-ccm+, AVL Fire, Ansys Fluent, Converge), 1D systems softwares (Matlab simulink, GT-Suite, Ricardo Wave allowing 1D/3D-coupled analyses to be performed effortlessly) and FEA software (Abaqus, Ansys, Nastran) for engine cylinder coupling, exhaust aftertreatment coupling, and fluid-structure interaction coupling simulation.
Using mentioned methods, enable us for development of intake runner systems and investigate the ways of improving mixing, and reducing cylinder-to-cylinder variations in air/fuel ratios and exhaust gas recirculation (EGR). The location of EGR pipes and their design can be determined and the dynamics of the intake system can be optimised. This analysis approach can also be used on exhaust components. Exhaust runner lengths and catalyst cone designs can be investigated and lambda sensor locations can be determined. After-treatment simulations can also be performed looking at catalyst utilisation, light-off potential and selective catalytic reduction (SCR) system design.
Acoustic Engineering: Innovative use of Coupled CFD and FEA simulation Tools
Esimlab as Engineering Simulation Laboratory, with deep knowledge in CFD and FEA and using advanced computational tools, supports customers and provides the latest NVH methodologies. Work together with our customer in Acoustic Engineering lead to NVH engineering section capabilities to develop individual solutions based on customers needs.
Esimlab ‘s major NVH services are:
- Engine and Powertrain NVH
- Vehicle and Powertrain NVH Simulation
- Sound Engineering
- NVH Software training and Methodology Development
The excellent know-how and innovative ideas as well as the strong link of the NVH team to other skill teams within Esimlab, ensures a successful outcome for each and every project and generates an additional benefit for our customers.
Using Simulation to Optimize Reacting Flows and Combustion
From automobile engines to gas turbine generators, reacting flow and combustion is often the key to energy efficiency, emissions, lifespan, product yield, and other performance parameters. Simulation help look deeper into reacting flow and combustion issues to understand the complex chemical reactions, fluid flow, heat transfer, electrical performance, and other factors that determine the performance of your product. Simulation enables our engineers to evaluate more design alternatives more thoroughly than traditional prototype-based design and development methods. They can confidently diagnose design alternatives to understand which potential design changes have the best change of improving product performance and evaluate enough design alternatives to get the design right before building a physical prototype. In such complicated Multiphysics environment including different solid and fluid and interaction between fields, enforce us to use advanced computational tools with innovative methods to capture real world simulation and optimize system to reduce cost and maximize performance considering short time for design in world competition.
Combination of advamced computational fluid dynamics (CFD) combustion simulation tools such as Kiva, Ansys Fluent, Ansys Forte, AVL Fire, Converge CFD, Siemens Star-ccm+ and System Modeling software such as Matlab Simulink and GT-Suite with sophisticated FEA tools such as Abaqus, Ansys, LS-DYNA and Nastran enable Esimlab engineering team to solve any engineering problem with any level of complexity in real world simulation and optimize component and processes of the system in real service load condition considering interaction between them.
Comprehensive IC Engine Flow and Combustion Simulation: modeling gas phase and surface chemistry
Comprehensive IC engine flow and combustion simulation from ANSYS bring together the best of both worlds: optimal CFD solvers and the best combustion chemistry tools.
ANSYS’ IC engine solution suite includes ANSYS Forte (specialized CFD for IC engine combustion) and ANSYS CHEMKIN-Pro (combustion-chemistry gold-standard) along with the leading general-purpose CFD solvers ANSYS Fluent and ANSYS CFX. These products deliver the most comprehensive solutions available for IC engine flow and combustion simulation:
- transient and steady-state flow
- Spray simulation including nozzle internal flow, primary breakup, secondary breakup, collision and coalescence, vaporization and spray-wall interactions
- advanced spark-ignition kernel and flame-propagation modeling
- using advanced chemistry solution and multicomponent spray vaporization to enable prediction of fuel effects on ignition, knocking and emissions
- coupling with fluid and thermal solvers for thermal structural durability
- tracking soot particle nucleation, growth, agglomeration and oxidation