Internal Combustion Engines
Reaction Design offers simulation and modeling products specifically created to support the development of modern internal combustion engines.
Accurately Predict Emissions
FORTÉ’s unique ability to incorporate more detailed chemical models in high fidelity CFD simulations without the traditional Time-to-Solution penalty enables more accurate prediction of engine emissions much earlier in the design process. Engine designers use FORTÉ to understand not only the magnitude of the emissions formed, but where they are being formed and why.
- Modeling of emissions behavior as a function of changes in fuel composition for conventional and alternative fuels.
- Automated parameter studies that predict the impacts of varying amounts of EGR on NOx, soot, CO and Unburned Hydrocarbons in both Spark-Ignited (SI) and Compression-Ignited (CI) engines.
- Simulation of the effects that take place in small regions, such as crevices, on CO and UHC emissions.
Engine designers can take advantage of CHEMKIN-PRO’s ability to perform rapid parameter studies to model trends in how engine design variables affect pollutant emissions such as NOx, CO and Unburned Hydrocarbons (UHC). The trends identified through the use of CHEMKIN-PRO simulations help guide conceptual design and answer key questions that arise during the engine design process.
Using CHEMKIN-PRO, designers can:
- Perform NOx, CO and UHC investigations using the Multi-Zone Engine Model for HCCI combustion.
- Use closed homogeneous reactor studies to determine the impacts of fuel composition and operating conditions on pollutant emissions.
- Develop and test detailed soot particle models for use in CFD.
Track Soot Particle Formation and Emissions
The FORTÉ CFD Package has the proven capability to handle chemistry models that predict how soot is formed in internal combustion engines, as well as to predict particle number and size. FORTÉ’s soot prediction approach supports the tracking of multiple soot precursors, the nucleation of the primary soot particle and the tracking of how a particle agglomerates and oxidizes through the engine cycle.
- The investigation of the effects of EGR and operating conditions on soot formation.
- The identification of the impact of fuel composition on soot formation for both direct-injected spark ignited and compression ignited engines.
- The prediction of the particle number and average particle size in the exhaust and locally in the cylinder during the cycle.
- The effects of injection location, spray characteristics and wall-film interactions as they impact soot formation.
Soot formation is a complex chemical and physical process that can be simulated in reduced order reactors. CHEMKIN-PRO supports two different particle tracking models that predict soot formation in idealized reactors. The Method-of Moments model enables predictions of average particle size and the Sectional Model predicts particle size distribution.
CHEMKIN-PRO enables designers to:
- Track the formation, agglomeration and oxidation of soot particles in the cylinder.
- Predict the impact of fuel composition changes on particle size.
- Gain information on the particle size distribution of soot in an engine.
FORTÉ supports simulation of knocking tendency that closely parallels how knock intensity is measured in a prototype test environment. FORTÉ takes advantage of accurate chemistry models to ensure the capture of chemical kinetics behavior that is critical to the accurate simulation of knock.
Using FORTÉ, engineers can:
- Automate parameter studies to map an engine’s knock intensity response to changes in EGR, engine boost, fuel composition and other conditions.
- Adjust the location of FORTÉ’s virtual knock sensors to match experimental setup for direct comparison.
- Identify the locations in the cylinder where auto ignition is most significant to guide design efforts to reduce knock.
- Make use of detailed fuel models that account for composition variations that affect knock, such as ethane, propane and other higher carbon-number components in natural gas, and accurately predict low-temperature combustion characteristics.
Knock in engines can affect durability, performance and the customer experience. Engine designers use CHEMKIN-PRO’s reactor models to understand how fuel composition and operating conditions impact engine knock by modeling auto-ignition behavior.
Using CHEMKIN-PRO, engineers can:
- Automate parameter studies to predict ignition delay as a function of fuel composition and operating condition variations.
- Investigate the chemical kinetics that occur during knocking.
Consider Injections Strategies
The comprehensive spray models in FORTÉ enable simulations with multi-component vaporization and fuel chemistry models for accurate combustion predictions. FORTÉ’s spray models improve Time-to-Solution by removing the mesh dependency and mesh refinement requirements of traditional CFD.
Use FORTÉ to:
- Perform fundamental spray bomb studies.
- Predict the effects of diesel injector design variables on combustion and emissions.
- Model multi-component spray vaporization in both diesel and direct injected gasoline engines.
Investigate Fuel Flexibility
Engine designers take advantage of FORTÉ’s ability to simulate multi-component liquid fuels with accurate fuel chemistry models to enhance engine fuel flexibility studies.
- Automated parametric studies to investigate the impacts of biofuel additives on ignition, flame propagation and emissions performance.
- Modeling of engine emissions changes when switching from gasoline to E85.
- The understanding of the ignition and flame propagation impacts when switching from diesel to biodiesel.
The ever widening fuels landscape presents a challenge to engine designers that can be addressed with Design of Experiment (DoE)-like studies in CHEMKIN-PRO. Biofuel and fuel additive impacts on combustion and emissions performance can be measured using CHEMKIN-PRO’s automated Parameter Study Facility.
This capability can:
- Simulate ignition delay impacts due to variations in the composition of natural gas, gasoline, diesel, biofuel and the addition of fuel additives.
- Enable flame propagation comparisons between conventional and alternative fuels using the Flame Speed Model.
- Generate laminar flame-speed libraries from detailed chemistry that can be used as the basis for turbulent flame propagation models in CFD.
Explore Dual Fuel Concepts
FORTÉ is the only CFD package available that supports the level of detailed chemical and physical models necessary to deliver accurate predictions of the behavior of dual fuel engines. FORTÉ enables designers to investigate the impacts of engine operating conditions, staged injection and fuel composition on engine performance through simulation.
Using FORTÉ, designers can:
- Compare how changes in the ratio of the port-injected and direct-injected fuels affect combustion and ignition behavior.
- Investigates the impacts of operating conditions and injection characteristics for best performance and lowest emissions.
- Simultaneously consider both flame-propagation and auto-ignition modes of combustion, using detailed chemical kinetics.
- Investigate power and efficiency impacts of dual fuel performance in large bore engines for ships and stationary power generators.
CHEMKIN-PRO’s reduced order models enable rapid investigation of performance and emissions trends that can influence the design of dual fuel engines. Dual fuel strategies focus on optimal use of the kinetics benefits of two fuels to improve efficiency and reduce emissions, for both low-load and high-load operation. The impacts of dual-fuel strategies can be predicted using CHEMKIN-PRO’s ignition delay and flame speed models.
These models enable:
- The understanding of how ignition delay is affected by changes in the relative proportion of the two fuels in the engine.
- The simulation of the impact of dual fuel compositions on laminar flame speed, which in turn, affects flame propagation.
- Insight into the impact of EGR on flame speed and ignition delay.
Model Fuel Efficiency
Engine designers use the FORTÉ CFD Package, which makes use of the industry’s most accurate fuel chemistry and spray models in simulations to predict the impact of multiple engine design attributes on engine power, net heat release rate, emissions.
With FORTÉ, designers can:
- Use a multi-component chemistry model coupled with a multi-component vaporization model to investigate the combustion behavior of direct injected engines.
- Assess the impacts of Exhaust Gas Recirculation (EGR) for NOx control on flame propagation and engine efficiency.
- Perform parameter studies on staged injection in Compression Ignition (CI) engines to determine impacts on engine efficiency.
- Simulate dual fuel engines, such as diesel micro-pilot injection into port injected gasoline or natural gas engines, with consideration of both flame-propagation and auto-ignition modes of combustion.
Internal combustion engine designers are continually under pressure to reduce fuel consumption and improve efficiency. Engineers use CHEMKIN-PRO’s reduced order models to perform scoping studies, create virtual Design of Experiments (DoE) and other parameter studies to support conceptual design. CHEMKIN-PRO’s rapid Time-To-Solution enables investigations into the effects of fuel composition on combustion and emissions, such as:
- The impact of fuel composition for conventional and biofuels on ignition delay.
- The impacts of Flame propagation during the combustion cycle.
- The impacts of the use of different fuel compositions (or mechanisms) on the accuracy of combustion. performance predictions for specific engine simulations.
Selecting the optimum fuel surrogate and reducing the complexity of the fuel model for desired accuracy of specific simulation targets is easy with Reaction Workbench, an optional extension to CHEMKIN-PRO. The Surrogate Blend Optimizer in Reaction Workbench automatically determines the correct compositions of a multi-component fuel to match desired fuel properties and then merges the different component fuel mechanisms. Reaction Workbench then takes advantage of a series of well-established mechanism reduction approaches to obtain the minimum mechanism to predict desired simulation targets within specified error tolerance.
- Create multicomponent surrogate fuel blends for fuels such as diesel, gasoline and biodiesel for use in FORTÉ or CHEMKIN-PRO.
- Reduce a fuel mechanism while maintaining specific accuracy on targets such as flame speed, ignition delay, emissions and/or soot.
Investigate Aftertreatment Solutions
Engine aftertreatment systems are becoming more commonplace as engine designers work to comply with strict regulations of NOx, CO and Unburned Hydrocarbons (UHC). Engine aftertreatment designers use CHEMKIN-PRO to simulate the effectiveness of catalytic devices such as 3-way catalysts to remove NOx, CO and UHC’s.
- Simulation of 3-way catalytic converter performance for conversion of NOx, CO and UHC’s through catalytic surface reactions on a platinum/rhodium catalyst.
- Investigation of the impact of honeycomb catalyst geometry and operating conditions on the reduction of NOx, CO and UHC’s.