DROPLET COMBUSTION MODELS WITH CONDENSATI ON OF THE BURNT PRODUCTS

This article presents two different models of LOX droplet combustion i n a high temperature hydrogen gas atmosphere that take into account ho mogeneous condensation of the burnt products. These products mainly in clude water, which appears in gaseous phase in the flame sheet. Conden sation may occur in the neighborhood of the oxygen droplet whose surfa ce temperature is around 100 K. The goal of this paper is to determine the possible existence and influence of this phenomenon on the proble m. The gaseous flow outside the oxygen droplet is described with hypot heses similar to those leading to the quasi-steady theory and the famo us d2 law. Although both models are based on the same hypotheses for t he condensation process (local equilibrium), they differ as to the inf luence of the condensed water on the gaseous flow. From these two mode ls, under the assumptions made, the main conclusions are : 1. water co ndensation occurs in the vicinity of the oxygen droplet, 2. comparison of these results with those obtained without taking into account cond ensation shows an increase in the vaporized mass flow rate at the oxyg en droplet surface.