EXPERIMENTAL INVESTIGATION ON MARANGONI DROP RATIONS USING DROP SHAFTFACILITY

Experimental hardware has been developed to perform the experiments of drop Marangoni migration in the case of intermediate Reynolds numbers ina microgravity environment. The experiments were completed using th e drop shaft free fall facility with a 4.5 s microgravity period in th e Microgravity Laboratory of Japan. A special experimental method was designed for experimenting with a short microgravity period. In this e xperiment, the thermocapillary velocity of drop migration, driven only by the thermocapillary effect, was obtained. Experimental results sho w that Marangoni migration velocity depends on the temperature gradien t and the drop diameter For fixed experimental mediums; the thermocapi llary velocity of this present experiment is obviously smaller than th e one suggested by YGB linear theory. This conclusion agrees, in gener al, with that of the ground-based experiment. (C) 1998 Elsevier Scienc e Ltd. All rights reserved.