超臨界雰囲気下での燃料液滴の蒸発・燃焼計算の基礎を再考する

抄録

An overview of the fundamentals of droplet evaporation and combustion calculation at pressures above the critical values for the pure fuel or propellant injected in the liquid phase is provided. The basic methodologies for determining highpressure phase equilibria are outlined first, and the issues concerning the mutual diffusion coefficient in the critical state of a binary mixture are discussed. Then, the importance of a scheme to switch from the subcritical to the supercritical evaporation mode in the numerical simulation of droplet evaporation and combustion in a supercritical environment is stated. Finally, the condition under which the droplet undergoes transition from the sub-to-supercritical evaporation regime is identified in terms of the initial parameters such as temperature, density, heat capacity, and thermal conductivity of ambient gas and droplet.