Reimagining Solar Desalination: A Critical Review of Innovations in Spherical Solar Still Design and Performance Ahmed Kadhim Hussein, Farhan Lafta Rashid, Sana Gharsallah, Saif Ali Kadhim, Raad Z. Homod, et al. Heat Transfer, 2026 As climate change, rapid urbanization, and rising global demand continue to strain freshwater resources, the pursuit of sustainable and decentralized desalination solutions has become increasingly urgent. Solar‐powered water purification, particularly via passive systems, offers an environmentally sound and energy‐efficient pathway to address this challenge. Among the different solar still configurations, spherical designs (SPSS) stand out as a noteworthy advancement, based on their unique geometry that ensures uniform solar energy absorption, improved thermal efficiency, and a compact form suitable for off‐grid and remote applications.This review delivers an in‐depth and up‐to‐date examination of advancements in SPSS technology, focusing on recent integrations such as wick‐based evaporation systems, nanoparticle‐infused phase change materials (PCMs), reflective surfaces, internal baffles, and rotational mechanisms. Collectively, these improvements have led to significant enhancements in distillate output, with some designs achieving performance increases of up to 259% relative to traditional setups. By critically examining experimental research, modeling approaches, and techno‐economic evaluations, this review outlines the current landscape, identifies key limitations, and explores emerging strategies to enhance efficient and cost‐effective SPSS systems.The analysis underscores the role of SPSS as a promising and scalable method for generating clean water, particularly suited to sun‐rich regions facing resource constraints.
Magnetic-Field-Enhanced Solar Desalination: A Comprehensive Review of Advanced Configurations and Performance Improvements Ahmed Kadhim Hussein, Sana Gharsallah, Saif Ali Kadhim, Mohammed El Hadi Attia, Mohammed Kawa Rasul, et al. Heat Transfer, 2026 The accelerating global demand for clean and affordable freshwater, intensified by climate change, rapid population growth, and increasing water scarcity, has driven strong interest in sustainable desalination technologies. Solar stills represent an attractive passive solution for decentralized, off‐grid freshwater production; however, their practical deployment is constrained by inherently low thermal efficiency and limited distillate yield. In recent years, the integration of magnetic fields (MFs) has emerged as an innovative, low‐energy enhancement strategy that actively intensifies evaporation and heat transfer processes. This review presents a comprehensive and critical synthesis of recent experimental and numerical investigations on MF‐enhanced solar desalination systems, including their coupling with phase‐change materials, thermal energy storage units, nanofluids, and heat transfer fins. The analyzed studies consistently demonstrate that magnetic augmentation can increase freshwater productivity by up to 88.7% and improve thermal efficiency by up to 87.27%, depending on magnet configuration, field intensity, and system architecture. Beyond thermal performance, magnetic enhancement also delivers clear technoeconomic and environmental benefits, including reduced energy consumption, lower distilled water costs, shorter payback periods, and meaningful reductions in CO 2 emissions. In addition to consolidating recent advances in system design and magnetothermal mechanisms, this review identifies key scientific bottlenecks hindering large‐scale deployment, notably the lack of standardized MF protocols and limited long‐term field validation. By highlighting emerging hybrid magnetothermal configurations and data‐driven optimization strategies, this work provides a forward‐looking framework to accelerate the translation of MF‐assisted solar desalination from laboratory‐scale prototypes to reliable, scalable freshwater production systems for water‐stressed regions worldwide.
Entropy Analysis of Heat Transfer in Solid Torus with Isothermal Boundary Conditions Kumud Ranjan, Shafiq Mohamad, Sachindra Kumar Rout, Gloria Biswal, Jnana Ranjan Senapati Journal of Thermophysics and Heat Transfer, 2026 This paper examines the entropy generation in a vertically placed solid torus in the vicinity of natural convection using numerical method. The study was performed by exercising the variation in parameters such as the aspect ratio of the solid torus (2.5–7.5), surface temperature of the solid torus ranging between 375 and 600 K, and Rayleigh number ranging between [Formula: see text] for laminar flow. The study analyzes the effect of all these variables on convective heat transfer, airflow dynamics, and generation of entropy. The outcomes indicate that with an elevated Rayleigh number, a higher aspect ratio experiences an accelerated rate of heat loss but with a reduced pace. For a constant Rayleigh number and dimensionless surface temperature, with increment in the aspect ratio from 2.5 to 5, the value of nondimensional heat transfer strengthens by around 80% but it reduces by about 50% when the aspect ratio upsurges from 5 to 7.5. The production of entropy intensifies by approximately 1.5 times with a rise in Rayleigh number for a specified aspect ratio and surface temperature. Furthermore, the degree of irreversibility on the account of heat transfer is considerably higher than irreversibility caused by fluid friction and contributes a vital role in the production of entropy generation. The deviations encountered during the investigation are quantitively and pictorially presented for the entire parametric variations to provide a deeper understanding. These findings will provide a better insight for the industrial engineers dealing with the thermal management of the toroidal- shaped objects.
Computational Study on Natural and Mixed Convection Heat Transfer From a Rotating Solid Torus Suspended in Air: A Sustainable Thermal Management Approach Kumud Ranjan, Sachindra Kumar Rout, Gloria Biswal, Jnana Ranjan Senapati Advancing Sustainable Engineering Through Next Generation Thermo Fluid Systems, 2025 This numerical investigation examines laminar mixed convection around a vertically oriented, rotating solid torus suspended in air, with emphasis on the interplay between buoyancy and rotational effects. A detailed parametric analysis is performed over a range of Rayleigh numbers (10^3 to 10^7), rotational speeds (0 to 4), and aspect ratios (2.5 to 7.5) to quantify the heat transfer enhancement by the rotation of the torus. The temperature contours and the velocity vector plots are presented to elucidate the underlying flow physics and heat transfer mechanisms for both rotating as well as non-rotating cases. Utilizing natural convection to cool rotating components eliminates the need for energy-intensive active cooling systems, thereby enhancing overall energy efficiency and aligning with sustainable engineering principles.