International Journal of Science, Engineering and TechnologyAuthors: Research Scholar Nitin Kumbhare, Assistant Professor Dr. Pranay A. Bagde
Abstract: This paper compares semi-circular and parabolic perforated absorber shapes for a forced-convection solar air heater. Regular and zigzag patterns in inward and outward orientations were assessed from 11:00 to 15:00 using temperature, airflow and solar-irradiance data. A simple numerical comparison was also used to check the observed performance trend. The parabolic zigzag-outward absorber gave the best result, with 28.70% measured efficiency and a heat-transfer rate of 75 W/m² at 14:00. At the same condition, the semi-circular zigzag-outward design reached 27.07% efficiency and 53 W/m². The numerical estimate for the best parabolic case was 31.10%, which was 2.40 percentage points above the measured value. The results show that curved shape, staggered placement and outward orientation can improve air mixing and useful heat output without making the collector arrangement unnecessarily complex.
