Determination of ability of machines with hydraulic drive during start-up in low ambient temperatures

Combustion processes of liquid fuels are more complicated than gases fuels ones. With reference to liquid fuels appear additionally fuel vaporization processes and e.g. with reference to solid fuels - decomposition of the solid phase with processes melting, vaporization, pyrolysis, or gasification. Those processes demand a lot of heat, go ahead slow down than processes in gas phase. The influence of the gases pressure on combustion of liquid and solid fuels, where controlling processes are processes decomposition of these phases, is more complicated and fundamentally differs from the influence of the pressure on combustion processes of gases fuels. The influence is characterized to these that pressurization decreases the intensity decomposition both the liquid phase, and solid one. In the paper assumptions to a model of the combustion process and the model of combustion processes of liquid fuels are presented. Research of the atomization process, ignition and combustion with the using of the LDV and PDPA Doppler laser-equipment and PIV are presented in the paper. Research results of the atomized fuel spray concerning droplet diameters, research result of the atomized fuel spray concerning linear and volumetric dropletlet dispersion, Rosin-Rammler dependences, and results of the analysis of the combustion rate are presented in the paper. On combustion rate of liquid fuels, the essential influence has a kind (laminar, transient and turbulent) and the thickness of the thermal boundary layer around the fuel droplet.