Abstract
Natural thermal convection of different unmixed liquids is quite different from that of a single liquid because of the existence of liquid-liquid interface. In order to clarify this phenomenon, it is necessary to know both flow and temperature fields of different unmixed liquids. In the present paper, natural convection of different unmixed liquids in a cubic enclosure with isothermal hot and cold walls was investigated. Influence of difference of kinematic viscosities and volume ratio of two liquids on flow and temperature fields were experimentally studied. Temperature distribution on a central cross section was visualized by thermosensitive liquid crystal particles. The conclusions derived from the above experiment are as follows: As the thermal movement occurs through the interface, the reverse speed of two kind of liquids near the interface was promoted. And beside the main circulation that occurred in the liquids of higher volume ratio and lower viscosity ratio, the secondary circulation was caused in the upper liquid.
