Numerical Optimization of Spray-Guided Spark Assistance for Cold Idle Operation in a Heavy-Duty Gasoline Compression Ignition Engine

Journal Article · Thu Jan 05 00:00:00 EST 2023 · Energies

DOI:https://doi.org/10.3390/en16020637· OSTI ID:2404358

Zhao, Le ^[1]; Zhang, Yu ^[1]; Pei, Yuanjiang ^[1]; Zhang, Anqi ^[1]; Ameen, Muhsin M. ^[2]

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1. Aramco Americas, Detroit, MI (United States). Aramco Research Center
2. Argonne National Laboratory (ANL), Argonne, IL (United States)

This article describes the results of a response surface model (RSM)-based numerical optimization campaign for spray-guided spark assistance at cold operations in a heavy-duty gasoline compression ignition (GCI) engine. On the basis of an earlier work on spark-assisted GCI cold combustion, a space-filling design of experiments (DoE) method was first undertaken to investigate a multitude of hardware design variables and engine operating parameters. The main design variables included the number of injector nozzles, fuel split quantities and injection timings, and spark timing. The objective variables were engine combustion efficiency (ŋ_c), maximum pressure rise rate (MPRR), and engine-out nitrogen oxide (NO_x) emissions. A total of 150 design candidates were automatically generated using the Sobol sequence method provided by the commercial software package, CAESES. Then, closed-cycle computational fluid dynamic (CFD) spark-assisted GCI simulations under cold idling operations were performed. The outcomes from the CFD-DoE design campaign were utilized to construct high-fidelity RSMs that allowed for further design optimization of the spark plug- and fuel injector-related design variables, along with fuel injection strategy parameters. A merit function with respect to objective variables was formulated with an appropriate weight assignment on each objective variable. Finally, the best design candidate was identified from the RSM-based optimization process and further validated in the CFD analysis. The best design candidate showed the potential to significantly improve combustion efficiency (ŋ_c > 90%) over the baseline at cold idle while satisfying MPRR and NOx emissions constraints (MPRR < 5 bar/CAD and NO_x < 4.5 g/kWh).

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC02-06CH11357
• OSTI ID: 2404358
• Journal Information: Energies, Journal Name: Energies Journal Issue: 2 Vol. 16; ISSN 1996-1073
• Publisher: MDPI
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
CFD
cold operation
design of experiments
gasoline compression ignition
optimization
spark assistance