Nanocrystalline ZrO2 with particle size of about 38 nm was directly synthesized by sol-gel auto-combustion method. The overall process involved three steps: formation of homogeneous sol at 50-55°C; formation of dried gel at 110°C, and combustion of the dried gel at 400°C. Experiments revealed that ZrO2 dried gel derived from glycine (Fuel) and nitrate sol exhibited self pr...

The present study uses a numerical model to investigate the effects of flow turbulence on premixed iso-octane HCCI engine combustion. Different levels of in-cylinder turbulence are generated by using different piston geometries, namely a disc-shape versus a square-shape bowl. The numerical model is based on the KIVA code which is modified to use CHEMKIN as the chemistry solver. A detailed react...

In this study a multi-objective genetic algorithm approach is developed for determining new reaction rate parameters for the combustion of kerosene/air mixtures. The multi-objective structure of the genetic algorithm employed allows for the incorporation of both perfectly stirred reactor and laminar premixed flame data into the inversion process, thus producing more efficient reaction mechanisms.

Homogenous charge compression ignition (HCCI) combustion is spontaneous multi-site combustion of a nominally premixed air/fuel mixture that exhibits high rate of pressure rise and short combustion duration. To avoid excessive pressure rise rate and knocking, HCCI engines are fueled with highly diluted mixture using a combination of excess air and/or EGR. HCCI combustion is attractive due to ...

The necessity for turbulent combustion modelling in the large-eddy simulation (LES) of premixed turbulent combustion is evident from the computational cost and the complexity of handling ame kinetics reaction mechanisms directly. In this paper a new ame-wrinkling LES combustion model using conditional ltering is proposed. The model represents an alternative approach to the traditional ame surfa...

2 Abstract`A three-dimensional reacting flow modeling approach is presented for predictions of compression ignition, combustion, NOx and soot emissions over a wide range of operating conditions in a diesel engine. The ignition/combustion model is based on a modified eddy dissipation concept (EDC) which has been implemented into the KIVA 3V engine simulation code. The modified EDC model is used ...

For large and complex reacting systems, computational efficiency becomes a critical issue in process simulation, optimization and model-based control. Mechanism simplification is often a necessity to improve computational speed. We present a novel approach to simplification of reaction networks that formulates the model reduction problem as an optimization problem and solves it using geneti...

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 ...