Investigation and performance enhancement of a novel multistage parabolic trough collector: Combined analytical modeling and CFD simulation

This study introduces a novel multistage parabolic trough collector (MPTC) design to enhance the efficiency of solar thermal systems. A new analytical model is developed to capture the optical, thermal, and fluid dynamic behaviors of both serial (MPTCS) and parallel (MPTCP) configurations. The model is validated using comprehensive three-dimensional computational fluid dynamics simulations performed with the SST k–ω turbulence model and Rosseland radiation approach. Comparative analysis with conventional parabolic trough collectors (PTCs) demonstrated the superior performance of the proposed designs. The MPTCS achieved up to a 28.5% increase in outlet temperature relative to inlet conditions, compared to only 14.5% for conventional PTCs. Parametric studies revealed that reduced receiver diameter and lower fluid velocity enhance the temperature rise, whereas incidence angle had only a minor effect. These results highlight the potential of MPTCs to deliver higher thermal efficiency and improved system performance for solar thermal energy applications. The findings provide a foundation for future prototype development and experimental evaluation.