The cubic and quadratic temperature dependences of the ratio of the concentration Rayleigh number to thermal Rayleigh number (RaC / RaT) were established for moist air and air- undecane vapor mixture, respectively.
The neglect of the phase transitions of moisture at 38 C and the use of RaT instead of the effective Rayleigh number lead to an error of 100%.
At high temperatures, an ordered convective motion exists solely due to the evaporation and condensation of water on opposite heat exchangers.
Somov S.A., Ivanov A.S. Experimental study of thermoconcentration convection in air-water and air-undecane mixtures // Physics of Fluids, 2024, Vol. 36, Iss. 10. Art. no. 104104.