Solutions
From predictive SI and diesel combustion to detailed chemical kinetics for knock and emissions, GT-POWER provides the accuracy and speed needed to develop cleaner, more efficient engines across all combustion concepts and fuel types.
COMBUSTION & EMISSIONS
SI TURB
With SI Turb, users are provided a two-zone, entrainment and burn-up model which also include:
DIPULSE
With DIPulse, users are provided a phenomenological combustion model that’s designed to handle modern multi-pulse injection.
DIPulse capabilities include:
FAST CHEMISTRY SOLVER
ACT (Advanced Combustion Toolset) is a collection of productivity tools that enable both increased model fidelity and faster runtimes. It includes a state of the art chemical kinetics solver that offers significantly improved computational times, enabling usage of more detailed mechanisms. Potential applications for detailed kinetics include:
Advanced Features
Explore advanced modeling capabilities for combustion analysis, emissions prediction, knock simulation, and thermal performance evaluation across a wide range of engine technologies.
Model any combustion concept, including SI, diesel, dual-fuel, pre-chamber, HCCI, and more, with any fuel, including hydrogen, ammonia, and methanol. This breadth of coverage eliminates the need for separate tools across different engine development programs.
Evaluate knock onset, intensity, and boundary conditions using detailed chemical kinetics or induction time integral models, enabling engineers to reduce reliance on costly prototype testing during combustion development.
Simulate both ensemble-averaged mean cycle combustion and individual cycle-to-cycle variation within a single modeling environment, providing a complete picture of combustion stability and variability.
Calculate any emissions species, including NOx, HC, CO, soot, and beyond, using detailed kinetics or partial equilibrium solvers, delivering the accuracy required for regulatory compliance and emissions optimization work.
GT-POWER's in-cylinder flow and turbulence model is fully coupled to combustion and heat transfer, ensuring that changes to geometry, valve events, or operating conditions propagate consistently across all physics simultaneously.
Combustion models interact directly with the cylinder finite element wall temperature solution, enabling accurate prediction of thermal loads, part load behavior, and dynamic operation, which is critical for durability and efficiency analysis.
Find answers to common questions about combustion and emissions.
GT-POWER predicts 13 combustion products by default, including NOx, CO, CO2, H2O, and SO2, using equilibrium chemistry, with the option to apply chemical kinetics for species where reaction timing matters, such as NOx and CO. CO2 is always calculated automatically as a primary product of hydrocarbon combustion. For NOx specifically, predictions are calibrated against measured data using the Extended Zeldovich mechanism, with the Stratified Burned Zone approach available for improved accuracy under stratified combustion conditions.
GT recommends calibrating NOx sequentially after predictive combustion model calibration, using just two multipliers: the NOx Calibration Multiplier and the N2 Oxidation Activation Energy Multiplier, to keep the optimization problem computationally manageable. A single set of calibration constants applied across all operating points is preferred over point-by-point tuning, which can produce unphysical results outside the calibration range. When preparing models for real-time applications, recalibration of the NOx model using the full Fast Running Model is recommended if time step size increases significantly.
Yes. When emissions species are known from test data, they can be imposed directly in the cylinder model using the EngCylEmisMaps object, with values entered as constants, map-based dependencies on engine speed or load, or actuated dynamically from a control system. This approach is particularly useful for system-level models where combustion detail is not the primary focus but accurate exhaust composition is still required downstream.
Burn rate controls the rate at which fuel and air are transferred to the burned zone, while heat release rate reflects the actual thermal energy released, which lags the burn rate when intermediate combustion products form before complete oxidation occurs. GT-POWER uses burn rate as the simulation input, never heat release rate directly; apparent heat release is available as a calculated result for comparison against pressure-derived measurements. Understanding this distinction is essential for correctly interpreting simulation outputs and avoiding calibration errors when comparing GT-POWER results to dynamometer data.
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