SOME ASPECTS OF HETEROGENEOUS PROCESSES OF THE COMBUSTION INCLUDING TWO PHASES

The combustion of fuels, aside from their state concentrations (solid, liquid, gas), always occur in the gas phase. Next gas phase which is the mixture of the fuel and air or the fuel and oxygen, as well as of the fuel and gases containing oxygen can occurs in the form premixed - homogeneous or not premixed - heterogeneous. Processes of the combustion of liquid fuels and solid are more complicated than combustion of fuel gases. With reference to liquid fuels occur additionally processes of the vaporization of the fuel, and with reference to solid fuels - decomposition of the solid phase with processes of melting and vaporization , pyrolysis, or gasification. This simultaneous and also different influence of different parameters is sometimes a reason of incorrect interpretation of experimental results. The study of the theoretical model of the combustion process concerning of liquid fuels and solid and which then the model takes into account also the gas- phase , because combustion processes take place in this phase and occurs the interaction of the phase gas- and liquid or the solid one. The theoretical model is presented basing on experimental initial researches realized in model with reference to liquid fuels and solid ones. Researches realized in the constant volume chamber with measurements of the pressure during the process of the combustion with the use of quick photography and with measurement of the distribution of the velocity in the spray of the fuel and droplet measurements by means the laser Doppler equipment LDV and PDPA. There were obtained the good agreement of findings experimental researches with the theoretical model. Generally on the combustion velocity of liquid fuels and solid one significant influence has a kind (laminar, temporary and turbulent) and the thickness of the thermal boundary layer.