Regular Article

Experimental study on the evaporating progress of hexane lenses on water surface with different temperature^★

¹ Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, Tianjin 300134, P.R. China
² International Centre in Fundamental and Engineering Thermophysics, Tianjin University of Commerce, Tianjin 300134, P.R. China

^* e-mail: lbtjcu@tjcu.edu.cn

Received: 2 June 2020
Received in final form: 21 August 2020
Accepted: 24 August 2020
Published online: 24 September 2020

Abstract

The evolution of an evaporating liquid on another nonmiscible fluid is important for many applications. An experimental study on the evaporation process of hexane lens on the surface of deionized water at different temperatures was carried out, and the surface temperature distribution characteristics and internal flow pattern evolution was analyzed. Results show that the surface temperature of hexane lens can be divided into two parts or three areas depending on the temperature of deionized water. The increasing temperature of deionized water gradually changes both vertical temperature gradient and radial temperature gradient inside hexane lens, and their competition determines the flow pattern inside the hexane lens. Flow along hexane edge caused by circumferential surface tension gradient forms a “low temperature channel” between the central low temperature region and the strong evaporation edge. The knowledge will benefit the fundamental understanding of evaporation characteristics of volatile droplets on a liquid surface.