Design of synthetic EGR and simulation study of the effect of simplified formulations on the ignition delay of isooctane and n-heptane

Abstract

A method to create synthetic mixtures that simulate the Exhaust Gas Recirculation (EGR) of an internal combustion engine, using O 2 , N 2 , CO 2 , H 2 O and Ar, has been designed. Different simplifications of this synthetic EGR error increases with temperature and decreases with pressure, equivalence ratio and oxygen mass fraction. Finally, the limit oxygen mass fractions for the use of each simplification have been obtained. Based on these results, it can be concluded that the only gas that can be obviated to keep the error in ignition delay under 1% is Ar.

Two-stage Lagrangian modeling of ignition processes in ignition quality tester and constant volume combustion chambers

“…The ignition properties of iso-octane were previously investigated in shock tubes and RCMs in [9,30,31].…”

“…However, very little effort was made to study ignition properties of iso-octane in IQTs. Similarly, the ignition characteristics of n-heptane fuel were extensively investigated in RCMs and shock tubes in [4,10,28,31]. n-Heptane ignition has been investigated experimentally and numerically in an IQT by Bogin et al [32][33][34].…”

A phenomenological explanation of the autoignition propagation under HCCI conditions

“…Different Wika piezo-resistive pressure sensors are available to control the filling of the combustion chamber (0.01 bar of resolution). In this study, EGR was considered as the products of a complete combustion reaction between the fuel and dry air in which the amount of oxygen is the one desired by the user, as explained in [21]. The combustion chamber is scavenged several times before the filling to avoid the contamination of the mixture by residual gases, while the fuel is directly injected into the combustion chamber at the beginning of the intake process to avoid problems of stratification.…”

A new method to predict high and low-temperature ignition delays under transient thermodynamic conditions and its experimental validation using a Rapid Compression-Expansion Machine

“…The synthetic air-EGR mixture is prepared in the mixing tank by a filling based on partial pressures. In this study, EGR was considered as the products of a complete combustion reaction between the fuel and dry air in which the amount of oxygen is the one desired by the user, as explained in [30]. The combustion chamber is scavenged several times before the filling.…”