Heat transfer and fluid dynamic performances of a stepped solar still: CFD simulation and experimental validation

Abstract

Abstract In this work, a novel transient CFD modeling procedure for a stepped basin solar still (SBSS) was developed, with no requirement to specify the glass cover and basin water temperatures as boundary conditions. The solar irradiation absorption and heat transfer by radiation in various elements of the SBSS were accounted for by solving the Rosseland, solar loading and solar ray tracing radiation equations. Instead of applying volume of fluid for multiphase techniques, RNG k-epsilon turbulence, water vapor species equations and energy equations were solved. This developed model was enabled to predict the SBSS performance with acceptable agreement after validation with the experimental results. The simulated and experimental daily accumulated productivities of the SBSS were 4557 mL m −2 and 4289 mL m −2 , with a 6.2% deviation. The experimental daily thermal efficiency at 1 cm water depth was 35.2%, while the simulated was 38.5%, with a 9.4% deviation.