Comprehensive Review of Thermal and Thermohydraulic Performance in Solar Air Heaters with Advanced Artificial Roughness Geometries
Year: 2025
Type: article
Abstract: This study provides a detailed review of the thermal and thermo-hydraulic performance of solar air heaters (SAHs) enhanced through the application of artificial roughness on the absorber plate. Various roughness geometries, such as wire ribs, V-shaped ribs, arc-shaped ribs, and rib-groove patterns, have been analysed to assess their influence on heat transfer enhancement and frictional behaviour. Findings from previous experimental and numerical studies reveal that the incorporation of artificial roughness can increase the Nusselt number by approximately 1.25 to 6.3 times and improve thermal efficiency by 20–35% when compared to smooth absorber plates. The review further highlights that the most effective performance occurs at a relative roughness height (e/D) between 0.02 and 0.05 and within a Reynolds number range of 10,000 to 18,000. Overall, the analysis confirms that artificial roughness is a simple, economical, and highly effective technique to enhance heat transfer and overall efficiency in solar air heater systems.
Source: Energies
DOI: 10.3390/en18236157
Authors: Rohit Singh, Ramadas Narayanan
Institution: Central Queensland University
Language: English
Topic: Heat Transfer Mechanisms
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,137
OpenAlex ID: W4416593168