The physicochemical characteristics of vegetable oils, the atomization and the particle size of the spray are fundamental aspects for the simulation of their combustion on burners. In this study, the influence of temperature and pressure on the disintegration of the jet of jatropha oil and its mixture with gas oil was simulated on a Riello Gulliver burner with power ranging from 22.5 to 35.6 KW. The disintegration and dispersion conditions of the droplets from the burner were determined using the average Sauter diameter by equations and mathematical functions. The results showed that there is a minimum temperature and pressure (130°C and 14 bar, respectively) from which it is possible to obtain an adequate disintegration of jatropha oil and its mixtures with diesel with suitable selected type of burner. These simulation results are consistent with results obtained experimentally and show satisfactory disintegration conditions at low pressure.

No abstract

This work is largely devoted to a review of existing works in the literature on single and multi-zone models of thermodynamic combustion in a diesel engine. It is found that numerical simulations of diesel engine operation based on thermodynamic models are of great interest in predicting engine performance and developing new concepts.  Also, the advantages and disadvantages of the different models of a multi-zone are given. This study summarises several studies over several years of these thermodynamic models in use by presenting the different results.  The limitations of the single-zone model led to the development of the multi-zone thermodynamic combustion model. This work therefore suggests a comprehensive study that takes into account the different models (kinetics, fuel flow, injection, heat transfer, etc.) to better appreciate the performance of the diesel engine.  This will give a clear idea of how to develop new concepts for single-zone or multi-zone thermodynamic modelling that will help car manufacturers, for example.

This work concerns the technical study of implementation, thermal and mechanical characterization of a composite material based on clay and plant fibers, in order to meet the need for bioclimatic and sustainable houses. The objective was to find the proportions of clay and fibers to obtain a mixture that would give better thermal properties. A characterization of the thermal properties was made thanks to the KD2 Pro analyzer on samples of various formulas of mixture clay-plant fibers. The results obtained showed that the thermal properties such as thermal conductivity and thermal diffusivity of the clay-fiber mixture samples decrease with the increase of the fiber content in the mixture. Thus, the thermal conductivity of the samples varies from 0.85 to 0.65 W/m.K; from 0.88 to 0.72 W/m.K and from 0.83 to 0.75 W/m.K respectively with Hibiscus cannabinus L. fiber, sawdust and Oryza sativa husk. As for the thermal diffusivity, it varies from 0.37 to 0.25 mm2/s; from 0.45 to 0.30 mm2/s and from 0.47 to 0.27 mm2/s respectively with the addition of Hibiscus cannabinus L. fibers, sawdust and Oryza sativa husk. In sum, the earth samples stabilized with Hibiscus cannabinus L. fibers offer better thermal properties for the construction of bioclimatic houses.