The objective of this study is to investigate the combustion in a pilot-ignited supercharged dual-fuel engine, fueled with different types of gaseous fuels under various equivalence ratios. It is found that if certain operating conditions are maintained, conventional dual-fuel engine combustion mode can be transformed to the combustion mode with the two-stage heat release. This mode of combusti...

A novel numerical method has been developed to couple a recent high order accurate fully compressible upwind method with the Conditional Moment Closure combustion model. The governing equations, turbulence modelling and numerical methods are presented in full. The new numerical method is validated against Direct Numerical Simulation (DNS) data for a lean premixed methane slot burner. Although t...

Combustion instability of O2/kerosene, O2/kerosene/hydrogen, and O2/kerosene/hydrogen spray flame is numerically studied. The numerical results of combustion self-oscillation are consistent with the historical experiments. Hydrogen is helpful to stabilizing oxygen/hydrocarbon combustion. High gas injecting velocity of the coaxial injector would increase the combustion stability. Contrary to the...

Blast furnace gas is the byproduct of smelting steel production process, and is the important secondary energy source. It is can be used as fuel for engines to generate electricity for most middle and small steel enterprises. In order to understand the combustion mechanism and provide the basis for the design of blast furnace gas engine,premixed laminar combustion experiments of the blast furna...

To avoid the complexities associated with the droplet/vapor transport and nonuniform evaporation processes, a fundamental investigation of liquid fuel combustion in idealized configurations is very useful. An experimental–computational investigation of prevaporized n-heptane nonpremixed and partially premixed flames established in a counterflow burner is described. There is a general agreement ...

Combustion kinetics ...................................................................................................................................... 1 Physical mixing and its effects on ignition, propagation and extinction ...................................................... 2 Mixing ...........................................................................................................

A new combustion model is developed and applied to simulate combustion in dual-fuel engines in which the premixed natural gas is ignited by the combustion flame initiated by a diesel spray. The model consists of a diesel auto-ignition model and a flame propagation model. A G-equation model previously developed to simulate SI engine combustion was incorporated with an auto-ignition model to simu...

In the present study, we have formulated the G equation concept for large-eddy simulation (LES) of premixed turbulent combustion. The developed model for the subgrid burning velocity is shown to correctly reflect Damköhler’s limits for largeand small-scale turbulence. From the discussion of the regime diagram for turbulent premixed combustion, it is shown that given a particular configuration o...

The scalar mixing time scale, a key quantity in many turbulent combustion models, is investigated for reactive scalars in premixed combustion. Direct numerical simulations (DNS) of three-dimensional, turbulent Bunsen flames with reduced methane-air chemistry have been analyzed in the thin reaction zones regime. Previous conclusions from single step chemistry DNS studies are confirmed regarding ...

The development of combustion systems to minimize the emission of pollutants and to increase the system’s efficiency involves modifications of the combustion process using premixed systems and highly turbulent swirl stabilized flames. However, these modifications of the combustion process usually lead to stability problems caused by the appearance of combustion-driven oscillations. Therefore, i...