Transient Conjugate Heat Transfer and Thermo‐Hydraulic Evaluation of Recyclable Aluminum‐Can PCM Placement in a Forced Single‐Pass Solar Air Dryer

ABSTRACT Phase change material integration can extend the useful operating period of solar air dryers, but its thermal and hydraulic effects depend strongly on the position of the storage modules relative to the absorber and airflow path. This study compares four configurations of a forced single‐pass solar air dryer: C0 without PCM, C1 with recyclable aluminum‐can paraffin modules below the absorber, C2 with the modules inside the air channel, and C3 with split below‐absorber and in‐channel placement. A transient three‐dimensional conjugate CFD model was assessed against measurements of outlet‐air temperature, absorber temperature, pressure drop, PCM‐core temperature, and DSC‐calibrated apparent liquid‐fraction evolution. The placement comparison used the common measured boundary‐condition histories of April 15, 2025 in Gurugram, India, with and . Expanded uncertainty bounds were propagated for the principal thermal, hydraulic, and PCM indicators. PCM‐temperature RMSE remained within 0.79°C–0.98°C, while apparent liquid‐fraction RMSE remained within 0.0150–0.0220. Under these tested conditions, C3 provided the strongest day‐integrated balance among the PCM‐assisted configurations. It delivered MJ and reduced the underheating energy deficit to MJ, while C2 produced the largest mean pressure drop ( Pa) and blower energy ( Wh). C3 stored the highest PCM energy ( MJ), including 0.277 MJ of sensible and 0.610 MJ of latent storage. Thin‐layer drying analysis of the experimentally tested C0 and C3 cases identified the Midilli–Kucuk model as the best fit for both tomato and green chili. C3 reduced the observed drying time from 10.0 to 8.5 h for tomato and from 8.0 to 7.0 h for green chili. The findings identify split placement as the best balance among the tested PCM arrangements for the measured day and operating conditions. They do not establish seasonal, geographic, or product‐general superiority, which requires independent multi‐day and multi‐climate validation.