An Efficient and Unified Combustion Model for CFD of SI and CI Engine Operation

2017-01-0572

03/28/2017

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Event
WCX™ 17: SAE World Congress Experience
Authors Abstract
Content
In this work, an efficient and unified combustion model is introduced to simulate the flame propagation, diffusion-controlled combustion, and chemically-driven ignition in both SI and CI engine operation. The unified model is constructed upon a G-equation model which addresses the premixed flame propagation. The concept of the Livengood-Wu integral is used with tabulated ignition delay data to account for the chemical kinetics which is responsible for the spontaneous ignition of fuel-air mixture. A set of rigorously defined operations are used to couple the evolution of the G scalar field and the Livengood-Wu integral. The diffusion-controlled combustion is simulated equivalent to applying the Burke-Schumann limit. The combined model is tested in the simulation of the premixed SI combustion in a constant volume chamber, as well as the CI combustion in a conventional small bore diesel engine. The result shows satisfactory accuracy of the predicted cylinder pressure and heat release rate, while maintaining low computational cost. The combined model provides a natural, robust, and efficient solution to two difficult tasks in development-oriented computational-power-constrained engine simulation: a) to predict SI knock in G-equation simulation; b) to account for the CI induction time in spray combustion simulation at the Burke-Schumann limit.
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DOI
https://doi.org/10.4271/2017-01-0572
Pages
7
Citation
Wang, M., Gao, S., and Lee, C., "An Efficient and Unified Combustion Model for CFD of SI and CI Engine Operation," SAE Technical Paper 2017-01-0572, 2017, https://doi.org/10.4271/2017-01-0572.
Additional Details
Publisher
Published
Mar 28, 2017
Product Code
2017-01-0572
Content Type
Technical Paper
Language
English