A large eddy simulation (LES) model was developed to simulate the combustion process in a spark-assisted homogeneous charge compression ignition (SACI) engine. First, an ignition and flame propagation model based on a reaction progress variable is presented. The reaction progress variable is defined based on the normalized cumulative heat release. Transport equation for the progress variable is...

A rapid compression machine (RCM) test bench is developed in this study. The performance characterization and auto-ignition performance tests are conducted at an initial temperature of 293 K, a compression ratio of 9.5 to 16.5, a compressed temperature of 650 K to 850 K, a driving gas pressure range of 0.25 MPa to 0.7 MPa, an initial pressure of 0.04 MPa to 0.09 MPa, and a nitrogen dilution rat...

Homogeneous Charge Compression Ignition (HCCI) is an advanced combustion strategy that able to reduce nitric oxides (NOx) emissions and increase fuel efficiency simultaneously. This study investigated the effects of premixed kerosene fuel on the auto-ignition characteristics in a light-duty compression ignition engine. A partial HCCI engine was modified from a single cylinder, four-stroke, dire...

To acquire a high amount of information of the behaviour of the Homogeneous Charge Compression Ignition (HCCI) auto-ignition process, a reduced surrogate mechanism has been composed out of reduced n-heptane, iso-octane and toluene mechanisms, containing 62 reactions and 49 species. This mechanism has been validated numerically in a 0D HCCI engine code against more detailed mechanisms (inlet tem...

This article makes the argument that compression ignition combustion processes that are “flameless” with volumetric energy release, described as Low Temperature Combustion (LTC), are a thermodynamic pathway to maximizing the efficiency of reciprocating piston, internal combustion engines. The argument is built from the foundation of determining the maximum theoretical efficiency for an IC Engin...

Advanced combustion modes such as Controlled Auto-Ignition or Homogeneous Charge Compression Ignition have been under much attention due to their ability to reduce both emissions and fuel consumption. Thus, this paper aims at demonstrating the achievement of Controlled Auto-Ignition combustion on a standard 4-cylinder gasoline engine with negative valve overlap (NVO) and analyzing its performan...

Auto-ignition and combustion of single fuel droplets of methanol, n-heptane and iso-octane are studied. The numerical simulations are based on a detailed vaporization model, a detailed transport model and detailed chemical kinetics. The governing equations of the two phases are solved in a fully coupled way. The influence of different physical parameters like droplet temperature, gas phase temp...

The prediction of the auto-ignition delay time of fresh fuel in hot air is studied. This problem, encountered in many combustion systems, is in practice often calculated using a simple method, hereafter called homogeneous mixing ignition (HMI). This method however neglects transport effects and calculates local instead of global ignition properties. A second method is therefore studied called l...

Direct numerical simulation (DNS) is used to study chemically reacting, laminar vortex rings. A novel, all–Mach number algorithm developed by Doom, Hou, & Mahesh [1] is used. The chemical mechanism is a nine species, nineteen reaction mechanism for H2/air combustion proposed by Mueller et al. [2]. Diluted H2 at ambient temperature (300 K) is injected into hot air. The simulations study the effe...