Modeling of the vaporization front on a heater surface

摘要

The boiling-up of a metastable liquid with appearing vaporization fronts is theoretically considered. The boiling-up occurs usually on the surface of a heater. At the initial stage, growth of a spherical vapor bubble is observed. If the temperature of the liquid exceeds a threshold value, the vaporization fronts develop near the line of contact of a vapor bubble and the heater. The vaporization fronts extend along the heater with a constant speed. A model of steady propagation of the vaporization front is developed. The temperature and propagation velocity of the interface are determined from the balance equations of mass, momentum, and energy in the neighborhood of the vaporization front and from the stability condition of motion of the interface. It is shown that a solution of these equations exists only if the liquid is heated above a threshold value. The propagation velocity of the vaporization front also has the threshold value. The calculated velocity of interface motion and the threshold value of temperature are in reasonable agreement with available experimental data for various liquids within wide ranges of saturation pressures and temperatures of the overheated liquid.