Computational Fluid Dynamics-Based Characterization of Heat Transfer and Airflow in an Indirect Solar Fish Dryer Under Tropical Conditions

Abstract

Indirect solar drying is a widely adopted fish preservation technique in tropical regions, valued for its low energy requirement and capacity to enhance product quality. However, non-uniform airflow and temperature distribution within drying chambers remain persistent design challenges that compromise drying efficiency and product consistency. This study investigated the airflow characteristics and convective heat transfer performance of an indirect solar fish dryer through computational fluid dynamics (CFD) simulation and experimental validation. A three-dimensional CFD model was developed to simulate temperature distribution and airflow patterns under forced convection, with an inlet air velocity of 1.2 m·s⁻¹ and an inlet air temperature of 60 °C. Experimental air temperatures were recorded inside the drying chamber during actual drying operations and compared with simulated values using linear regression and root-mean-square error (RMSE). The regression analysis yielded a strong linear relationship between simulated and experimental temperatures (R² = 0.9413), with an RMSE of 3.41 °C, indicating reasonable agreement in absolute temperature prediction. These results confirm that the CFD model accurately represents the thermal behavior and convective heat transfer characteristics of the dryer. The validated CFD framework provides a reliable, cost-effective tool for evaluating and optimizing the design and operational performance of indirect solar fish dryers under tropical conditions, thereby reducing reliance on iterative physical prototyping.