# A numerical study on combustion mode characterization for locally stratified dual-fuel mixtures

Source: [A numerical study on combustion mode characterization for locally stratified dual-fuel mixtures](<https://www.sota2.com/research/paper/68fa3c401e209131ce8d9254>)

Collection index: [llms.txt](<https://www.sota2.com/research/llms.txt>)

Data updated: 2025-10-25T01:01:56.391Z

Authors: Shervin Karimkashi, Heikki Kahila, Ossi Kaario, Martti Larmi, Ville Vuorinen

Published: 2020-06-18T17:48:41.000Z

## Abstract

Combustion modes in locally stratified dual-fuel (DF) mixtures are numerically investigated for methanol n-dodecane blends under engine-relevant pressures. In the studied constant-volume numerical setup, methanol acts as a background low-reactivity fuel (LRF) while n-dodecane serves as high-reactivity fuel (HRF), controlling local ignition delay time. The spatial distribution of n-dodecane is modeled as a sinusoidal function parametrized by stratification amplitude (Y) and wavelength (0.01 mm\<$\\lambda$\<15 mm). In contrast, methanol is assumed to be fully premixed with air at equivalence ratio 0.8. First, one-dimensional setup is investigated by hundreds of chemical kinetics simulations in (Y,$\\lambda$) parameter space. Further, the concepts by Sankaran et al. 2005 and Zeldovich 1980 on ignition front propagation speed are applied to develop a theoretical analysis of the time-dependent diffusion-reaction problem. The theoretical analysis predicts two combustion modes, 1) spontaneous ignition and 2) deflagrative propagation, and leads to an analytical expression for the border curve called $\\beta$-curve herein. One-dimensional chemical kinetics simulations confirm the presence of two combustion modes in (Y,$\\lambda$) parameter space while the $\\beta$-curve explains consistently the position of phase border observed in the simulations. Finally, the role of convective mixing is incorporated to the theoretical expression for the $\\beta$-curve. The effect of convection on combustion mode is assessed by carrying out two-dimensional fully-resolved simulations with different turbulence levels. Two-dimensional numerical simulation results give evidence on combustion mode switching, which is consistent with predictions of the modified $\\beta$-curve for turbulent cases. The practical output of the paper is the $\\beta$-curve which is proposed as a predictive tool to estimate combustion modes ...

## Recorded benchmark results

A research result applies to its stated dataset, split, metric and evaluation configuration. Compare like-for-like settings, preserve the metric's unit and direction, and distinguish paper-reported results from independent reproduction. The best result recorded here is not a claim of exhaustive, current global coverage.

## Original sources and implementation

[Original paper](<https://arxiv.org/abs/2006.10718>)

[PDF](<https://arxiv.org/pdf/2006.10718.pdf>)