Effects of gravitational acceleration on high pressure combustion of methanol droplets
Résumé
A Franco-Japanese cooperative research program on microgravity combustion has been initiated. One of the studies is devoted to the experimental investigation of high pressure combustion of methanol droplets, under normal and reduced gravity conditions, which are obtained in a drop tower and during the parabolic flight of an airplane. A methanol droplet is suspended at the center of a high-pressure combustion chamber, and is ignited with an electrically heated kanthal wire. A high-speed video camera is used to obtain the time histories of the squared droplet diameter, which are used to determine the droplet burning rate. The results show that the d-square law is valid for all the conditions of the present experiments. The droplet burning rate increases with ambient pressure and does not show a maximum around the critical pressure of methanol. Experiments also show that the droplet burning rate decreases with the reduction of gravitational acceleration.