Horizontal convection driven by nonuniform radiative heating in liquids with different surface behavior

• Published in: International journal of heat and mass transfer 2018-11, Vol.126, p.400-410
• Main Authors: Vinnichenko, Nikolay A., Pushtaev, Alexey V., Plaksina, Yulia Yu, Rudenko, Yulia K., Uvarov, Alexander V.
• Format: Article
• Language: English
• Subjects: Background oriented schlieren; Horizontal convection; Particle image velocimetry; Surface phenomena
• ISSN: 0017-9310; 1879-2189
• DOI: 10.1016/j.ijheatmasstransfer.2018.06.036

[Display omitted] •Convection in liquids with free surface heated with infrared radiation is studied.•Instantaneous temperature and velocity fields are measured using BOS and PIV.•Results for water and ethanol are compared to analyze influence of surface behavior.•Marangoni convection in ethanol leads to quick dispersion of heat over surface layer.•Surface film in water corresponds to no-slip or zero surface divergence condition. Horizontal convection development in liquids with free surface nonuniformly heated by infrared radiation is investigated. Experimental measurements of velocity and temperature fields are performed by Particle Image Velocimetry (PIV) and Background Oriented Schlieren (BOS). Absence of Marangoni convection in distilled water due to presence of surface film leads to significant difference between the results obtained in distilled water and in ethanol. Strong Marangoni flow in ethanol results in quick dispersion of heat over the surface layer and acceleration of convective flow. In distilled water heat propagation along the surface is inhibited, because only weak secondary flow associated with 3D effects is observed at the surface. Experimental results are compared to numerical simulations with different boundary conditions for horizontal velocity at the free surface: no-slip condition for distilled water, representing stagnant surface film, and tangential-stress condition, taking into account Marangoni effect, for ethanol. Good agreement is obtained, demonstrating the importance of prescribing appropriate boundary condition, which corresponds to surface behavior of the considered liquid.