TY - JOUR

T1 - General correlations of iso-octane turbulent burning velocities relevant to spark ignition engines

AU - Nguyen, Minh Tien

AU - Yu, Dewei

AU - Chen, Chunyen

AU - Shy, Shenqyang

N1 - Publisher Copyright:
© 2019 by the authors.

PY - 2019

Y1 - 2019

N2 - A better understanding of turbulent premixed flame propagation is the key for improving the efficiency of fuel consumption and reducing the emissions of spark ignition gasoline engines. In this study, we measure turbulent burning velocities (ST) of pre-vaporized iso-octane/air mixtures over wide ranges of the equivalence ratio (φ = 0.9–1.25, Le ≈ 2.94–0.93), the root-mean-square (r.m.s.) turbulent fluctuating velocity (u0= 0–4.2 m/s), pressure p = 1–5 atm at T = 358 K and p = 0.5–3 atm at T = 373 K, where Le is the effective Lewis number. Results show that at any fixed p, T and u0, Le < 1 flames propagate faster than Le > 1 flames, of which the normalized iso-octane ST/SLdata versus u0/SLare very scattering, where SLis the laminar burning velocity. But when the effect of Le is properly considered in some scaling parameters used in previous correlations, these large scattering iso-octane ST/SLdata can be collapsed onto single curves by several modified general correlations, regardless of different φ, Le, T, p, and u0, showing self-similar propagation of turbulent spherical flames. The uncertainty analysis of these modified general correlations is also discussed.

AB - A better understanding of turbulent premixed flame propagation is the key for improving the efficiency of fuel consumption and reducing the emissions of spark ignition gasoline engines. In this study, we measure turbulent burning velocities (ST) of pre-vaporized iso-octane/air mixtures over wide ranges of the equivalence ratio (φ = 0.9–1.25, Le ≈ 2.94–0.93), the root-mean-square (r.m.s.) turbulent fluctuating velocity (u0= 0–4.2 m/s), pressure p = 1–5 atm at T = 358 K and p = 0.5–3 atm at T = 373 K, where Le is the effective Lewis number. Results show that at any fixed p, T and u0, Le < 1 flames propagate faster than Le > 1 flames, of which the normalized iso-octane ST/SLdata versus u0/SLare very scattering, where SLis the laminar burning velocity. But when the effect of Le is properly considered in some scaling parameters used in previous correlations, these large scattering iso-octane ST/SLdata can be collapsed onto single curves by several modified general correlations, regardless of different φ, Le, T, p, and u0, showing self-similar propagation of turbulent spherical flames. The uncertainty analysis of these modified general correlations is also discussed.

KW - General correlations

KW - High-pressure turbulent burning velocity

KW - Iso-octane

KW - Lewis number

KW - Self-similar spherical flame propagation

UR - http://www.scopus.com/inward/record.url?scp=85066761365&partnerID=8YFLogxK

U2 - 10.3390/en12101848

DO - 10.3390/en12101848

M3 - 期刊論文

AN - SCOPUS:85066761365

SN - 1996-1073

VL - 12

JO - Energies

JF - Energies

IS - 10

M1 - 1848

ER -