Practical simulation of industrial-scale coal combustion relies on the ability to accurately capture the dynamics of coal subprocesses while also ensuring the computational cost remains reasonable. The majority of the residence time occurs post-devolatilization, so it is of great importance that a balance between the computational efficiency and accuracy of char combustion models is carefully c...

A zero dimensional, mean-value, control-oriented model for recompression homogeneous charge compression ignition (HCCI) combustion with two discrete states representing temperature and composition dynamics is presented. This model captures steady state magnitudes and trends in combustion phasing, residual gas fraction, and mass flows caused by sweeps in valve timings, fueling rate, and fuel inj...

The present study focuses on the effect of air-fuel ratio on the performance of four cylinder hydrogen fueled direct injection internal combustion engine. GT-Power was utilized to develop the model for direct injection engine. Air-fuel ratio was varied from rich limit to a lean limit. The rotational speed of the engine was varied from 1250 to 4500 rpm. The acquired results shown that the air fu...

polycyclic aromatic hydrocarbons (pahs) are a group of organic compounds made up of two or more fused benzene rings in linear, angular or cluster arrangements. the pahs are formed by incomplete combustion or high temperature pyrolytic process involving organic matter. thirty sampling sites were selected to characterize the pahs concentrations in ambient air in tehran. sixteen pahs were measured...

The dual fuel engines at part loads inevitably suffer from lower thermal efficiency and higher carbon monoxide and unburned fuel emission. This work is carried out to investigate combustion characteristics of a dual fuel (dieselgas) engine at part loads, using a single zone combustion model with detailed chemical kinetics for combustion of natural gas fuel. The authors developed software in ...

This work is carried out to investigate combustion characteristics of a dual fuel (diesel-gas) engine at part loads, using a quasi-dimensional multi zone combustion model (MZCM) for the combustion of diesel fuel and a single zone model with detailed chemical kinetics for the combustion of natural gas fuel. Chemical kinetic mechanisms consist of 184 reactions with 50 species. This combustion mod...

To reduce the impact of combustion of fossil fuels on air quality and climate change, dimethyl ether (DME) is a promising alternative diesel fuel candidate. Technical combustion processes, including formation of pollutants, are influenced by turbulence–chemistry interaction. Therefore, accurate prediction by computational combustion models of combustion systems burning DME must account for mult...

To understand the effect of different thermal conductivities on catalytic combustion characteristics, effect of thermal conductivity on micro-combustion characteristics of hydrogen-air mixtures in Pt/γ-Al2O3 catalytic micro-combustors were investigated numerically with detailed chemical kinetics mechanisms. Three kinds of wall materials (100, 7.5, and 0.5 W/m·K) were selected to investigate the...

Cyclic variability (CV) in lean HCCI combustion at the limits of operation is a known phenomenon, and this work aims at investigating the dominant effects for the cycle evolution at these conditions in a multi-cylinder engine. Experiments are performed in a four-cylinder engine at the operating limits at late phasing of lean HCCI operation with negative valve overlap (nvo). A combustion analysi...