4. Conclusion

Our knowledge of the physico-chemical characteristics of fuels, thermochemistry and combustion processes has mostly been acquired in laboratories, by specialists in fundamental research, and under experimental conditions that are sometimes far removed from those encountered in engines and industrial furnaces.

However, all the concepts developed and defined in this way are extremely useful for the practitioner, particularly in the field of spark-ignition engines, where the processes of flame propagation, self-ignition or knocking and flammability limits can be described and analyzed using very precise theoretical notions.

However, this continuity between knowledge and observation is not yet guaranteed in heterogeneous combustion by diffusion flames, on diesel engines for example, where physical phenomena (penetration, disintegration, vaporization...