D Souza, David JonathanMontes Pita, María JoséRomero, ManuelGonzález Aguilar, José2025-10-092025-10-092025-01-19D’Souza, Montes, Romero, & González-Aguilar. (2025). Experimental assessment of different compact flow channel geometries on pressurised gas solar receivers. Applied Thermal Engineering, 266. https://doi.org/10.1016/j.applthermaleng.2025.1256341359-4311 | eISSN 1873-5606https://doi.org/10.1016/j.applthermaleng.2025.125634https://hdl.handle.net/20.500.14468/30352The registered version of this article, first published in Applied Thermal Engineering, 266, 125634, is available online at the publisher's website: https://doi.org/10.1016/j.applthermaleng.2025.125634La versión registrada de este artículo, publicado por primera vez en Applied Thermal Engineering, 266, 125634, está disponible en línea en el sitio web del editor: https://doi.org/10.1016/j.applthermaleng.2025.125634The authors wish to thank “Comunidad de Madrid” for the financial support to ACES4NET0-CM project (TEC-2024/ECO-116), through the R&D activities programme “Tecnologías 2024”. The authors wish to thank “Comunidad de Madrid” and European Structural Funds for the financial support to ACES2030-CM project (S2018/NMT-4367), through the R&D activities programme “Tecnologías 2018”.Pressurised gas receivers using optimised compact flow channels exhibit promising thermal performance in concentrated solar thermal systems, paving the way to integrate solar energy in high efficiency thermodynamic power cycles and industrial heat processes. This work is focused on the experimental characterisation of several compact absorber samples, in order to verify previous numerical analysis aimed at maximising thermal efficiency while simultaneously minimising pressure drop. Four variants of plain rectangular channel absorber samples were fabricated varying channel height, breadth and wall thickness. Each absorber sample was experimentally studied by varying mass flow rate, inlet pressure and incident radiation flux. The experimental campaign verified important findings and predictions of a previously developed numerical model including that the maximum thermal efficiency and pressure drop occurs at the smallest channel size besides the positive effect of taller and narrower channels. The maximum thermal efficiency observed was 95.8% with the corresponding pressure drop measured at 6.3% of the inlet pressure. This performance, in terms of thermal efficiency and relative pressure drops, is on par and even surpasses the state-of-the-art receivers of its type. Such high thermal efficiencies (above 90%) and low relative pressure drops (below 3%) were also observed for other operating conditions and absorber geometries as well.eninfo:eu-repo/semantics/openAccess3322 Tecnología energéticaartículoCompact channelExperimental characterisationPressurised gasSolar receiveConcentrated solar thermalParametric analysis