Premixed or partially premixed compression ignition modes, such as homogeneous charge compression ignition (HCCI), have been a particular focus among researchers because of their potential to deliver enhanced fuel efficiency and meet exhaust emissions mandates without the addition of costly after-treatment technologies as currently required with traditional spark ignition (SI) and direct inject...

Dynamics of ethylene autoignition and deflagration-to-detonation transition (DDT) are first numerically investigated in a one-dimensional shock tube using reduced chemistry including 10 species reactions. Different combustion modes through considering various premixed gas equivalence ratios (0.2 [Formula: see text] 2.0) incident wave Mach numbers (1.8[Formula: text]3.2). Four ignition DDT obser...

Mixing, ignition and combustion behavior in a rapid compression expansion machine operated under Premixed Charge Compression Ignition (PCCI) relevant conditions are investigated by combined passive optical laser-optical high-speed diagnostics. The PCCI concept is realized using split injection schedule consisting of long base load two closely separated short injections near top dead center. Pre...

Advanced combustion systems that utilize different modes and alternative fuels have significantly improved performance emissions compared to conventional diesel or spark-ignited combustions. As an fuel, dimethyl ether (DME) has been receiving much attention as it runs effectively under low-temperature (LTC) such homogeneous charge compression ignition (HCCI) reactivity control (RCCI). Under com...

Changing the compression ratio and presence of turbocharger are two important issues, affecting on performance, and exhaust emissions in internal combustion engines. To study the functional properties and exhaust emissions in regards to compression ratio at different speeds, the numerical solution of the governing equations on the fluid flow inside the combustion chamber and the numerical solut...

In modern engines with higher compression ratios, severe pressures and non-uniform heating up is occurred for the engine parts. The piston as the most critical part among all automotive components has been the subject of numerous studies on calculation of temperature distribution, but thermal stress analyses are limited. In this study, the piston of gasoline engine XU7 which is widespread in Ir...

Large-eddy simulations with a transported probability density function model coupled finite-rate chemistry is applied to study the ignition process of an n-heptane spray in constant volume chamber premixed methanol-air atmosphere under conditions relevant reactivity controlled compression (RCCI) engines. Three reacting cases initial equivalence ratio (?m) ranging from 0 0.3 are investigated at ...

We present 3D numerical results on tri-fuel (TF) combustion using large-eddy simulation and finite rate chemistry. The TF concept was recently introduced by Karimkashi et al. (Int. J. Hydrogen Energy, 2020) in 0D. Here, the focus is spray-assisted ignition of methane–hydrogen blends. spray acts as a high-reactivity fuel (HRF) while ambient premixed methane-hydrogen blend low-reactivity (LRF) mi...

Due to the serious issues caused by air pollution and global warming, emission regulations are becoming stricter. New technologies that reduce NOx and PM emissions are needed. To cope with these social exhaust gas regulation demands, many advanced countries are striving to develop eco-friendly vehicles in order to respond to stricter emissions regulations. The homogeneous charged compression ig...