A reduced-order model for turbulent reactive sprays in compression ignition engines

Combustion and Flame, vol. 236, pp. 111751

Abstract

In this work, we present a reduced-order model for transient turbulent reactive sprays in compression ignition engines. The model is an extension of the previously developed cross-sectionally averaged spray model (CAS) (Deshmukh et al., 2021). A transient turbulence model is derived for the gas phase that allows to model the transient scalar dissipation rate, which is a key parameter in non-premixed combustion. Representative chemistry is solved in mixture fraction space interactively with the flow. The turbulent CAS model combined with the combustion model is termed the cross-sectionally averaged reactive turbulent spray (CARTS) model and can represent unsteady non-premixed combustion behavior. The CARTS model is validated against experimental data as well as three-dimensional (3D) numerical simulations. The model is able to reasonably predict the trends of ignition delay time, flame lift-off length, and soot emissions. The computational cost of the CARTS model is orders of magnitude lower than the 3D simulation methods. This low computational cost enables various applications, including but not limited to the rapid screening of novel fuel candidates as well as off-line training of models to be eventually used in closed-loop control.

Authors 6

1. Abhishek Y. Deshmukh corresponding Aachen Institute for Combustion Technology

   RWTH Aachen University

   Affiliation as printed

   Institute for Combustion Technology, RWTH Aachen University, Templergraben 64, Aachen 52062, Germany

2. Marco Davidovic Aachen Institute for Combustion Technology

   RWTH Aachen University

   Affiliation as printed

   Institute for Combustion Technology, RWTH Aachen University, Templergraben 64, Aachen 52062, Germany

3. Temistocle Grenga Aachen Institute for Combustion Technology

   RWTH Aachen University

   Affiliation as printed

   Institute for Combustion Technology, RWTH Aachen University, Templergraben 64, Aachen 52062, Germany

4. Raghavan Lakshmanan Aachen Institute for Combustion Technology

   RWTH Aachen University

   Affiliation as printed

   Institute for Combustion Technology, RWTH Aachen University, Templergraben 64, Aachen 52062, Germany

5. Liming Cai

   Tongji University

   Affiliation as printed

   School of Automotive Studies, Tongji University, Shanghai 201804, China

6. Heinz G. Pitsch Aachen Institute for Combustion Technology

   RWTH Aachen University

   Affiliation as printed

   Institute for Combustion Technology, RWTH Aachen University, Templergraben 64, Aachen 52062, Germany