Validated theoretical model for IR-reflective heat transfer in cylindrical annuli: experimental, simulation, and application
Mohamad K. Ferrer P.
1 November 2025Elsevier Ltd
Applied Thermal Engineering
2025#278
This study presents a validated semi-analytical model for simulating infrared (IR) radiative heat transfer within the annular space between two concentric cylinders, where the inner surfaces are coated with spectrally selective IR-reflective materials. The model is developed from first principles and accounts for angle-dependent and coating-specific reflection properties. While prior studies have addressed radiative transport in cylindrical enclosures, this work is the first to integrate IR-selective coatings into the model and quantify their thermal impact in the context of practical applications such as solar thermal receivers. Model results show that selectively reflective surfaces can significantly suppress inward radiative losses and raise the outer cylinder surface temperature by more than 300 °C compared to baseline cases. This enhancement translates into notable improvements in the thermal energy retention of the system, with the coated configuration retaining 2.4 times more effective temperature difference than the uncoated configuration, equivalent to a 140 % improvement in effective heat retention. The proposed model is verified against classical radiative transfer solutions and serves as a versatile tool for guiding the design and optimization of IR-managed thermal enclosures.
Annulus , Coatings , Concentric cylinders , IR reflected mirror
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School of Physics, Materials for Energy Research Group, University of the Witwatersrand, Johannesburg, 2001, South Africa
School of Physics, Mandelstam Institute for Theoretical Physics, University of Witwatersrand, Johannesburg, 2001, South Africa
Faculty of Engineering and Natural Sciences, SDU University, Almaty, Kazakhstan
School of Physics
School of Physics
Faculty of Engineering and Natural Sciences
10 лет помогаем публиковать статьи Международный издатель
Книга Публикация научной статьи Волощук 2026 Book Publication of a scientific article 2026