in this paper, the effects of input temperature and compression ratio on the net output work and efficiency of the air standard cycles, i.e. atkinson cycle, diesel cycle and otto cycle are analyzed. we assumed that the compression and power processes are adiabatic and reversible and any convective, conductive and radiative heat transfer to cylinder wall during the heat rejection process may be ...

  This paper presents a modeling study of a CNG Homogenous Charge Compression Ignition (HCCI) engine using single-zone and multi-zone combustion models. Authors' developed code could be able to predict engine combustion and performance parameters in closed part of the engine cycle. As detailed chemical kinetics is necessary to investigate combustion process in HCCI engines, therefore, GRI-m...

The Internal Combustion (IC) Engine is perhaps the most wide-spread apparatus for transforming liquid and gaseous fuel to useful mechanical work. Homogeneous charge compression ignition (HCCI) is a new combustion technology that may develop as an alternative to diesel engines with high efficiency and low NOx and particulate matter emissions. The homogenous charge compression ignition (HCCI) is ...

5.1 ABSTRACT Supersonic combustion data obtained at the low static temperatures appropriate for an efficient scramjet engine are reviewed. Attention is directed at the methods by which the fuel was ignited and combustion maintained. The cited supersonic combustion experiments are grouped under the six headings: chemical intiators; non-uniform flows; turbulent flameholding; combustion induced co...

The reactivity of three Cu-, Fe-, and Ni-based oxygen carriers to be used in a chemical-looping combustion (CLC) system using syngas as fuel has been analyzed. The oxygen carriers exhibited high reactivity during reduction with fuel gases present in syngas (H2 and CO), with average values in the range 8-30 % min. No effect of the gas products (H2O, CO2) on the reduction reaction rate was detect...

This paper simulates the density and temperature fields in the process of mixture formation with two combustion modes in a Diesel engine. The computational simulations and experiments show that in the normal combustion mode, the density and temperature of mixtures change greatly in the combusting sprays so that there are premixed combustion and diffusion combustion simultaneously, which results...