Review on performance assessment of solar stills using computational fluid dynamics (CFD)

Environmental pollution and water resource management are some of the biggest challenges for the twenty-first century. The utilization of solar energy for water purification through solar stills is an environmental friendly and sustainable approach. Computational fluid dynamics (CFD) is a valuable and cost-effective tool for the simulation of fluid and thermal phenomena in solar stills as well as for their optimization for maximum productivity. The objective of the current study is to present a comprehensive review of the significance of the CFD tool in analysis, performance estimation, and design improvements of solar still. Various studies in this direction are classified according to the comprehensiveness of the modeling approach employed. The approaches are classified into three categories. The assumptions and governing equations for various approaches are presented. It is highlighted that the relatively simpler CFD modeling of only the humid air zone in the solar still, which relies on the availability of experimental data, the modeling approach has now evolved to an advanced level and can give predictive estimates by using only the ambient atmospheric conditions and solar irradiation as input. Various studies are also classified based on configurations, computational domain, and operational and geometrical parametric range. The key results from various CFD studies are summarized.