Akademik Veri Yönetim Sistemi
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW, cilt.109, ss.1-20, 2024 (SCI-Expanded)
Drying is used as a preservation method for berries and greenstuffs. Thanks to the drying process, most of the water in the food is removed, creating an unsuitable environment for the activities of microorganisms. In this study, the heat and mass transfer characteristics of semi-circular moist objects placed at different angles (θ) of 0°, 30°, 45°, 60°, and 90°, and at different distances (H/D) of 5, 4, and 3.33 parallel to the impinging hot air jet flow were numerically investigated. Numerical calculations were carried out by solving the forced convection heat and mass transfer equations for two-dimensional, steady, laminar, and incompressible flow using the Ansys-Fluent program. For drying, moisture transfer equations were also resolved by typing a User-Defined Function (UDF) code in Ansys-Fluent. While the temperature of the jet flow (Tjet) is 323 K, the moist object surface temperature (Ts) is 298 K. Calculations were conducted for different values of Re numbers: 300, 400, and 500. The effects of the placement angles and positions of the moist object on the average Nu number (Nua) were examined for different Re numbers. Additionally, temperature and moisture variations at the midpoint length of the object along the x-axis-(X) were evaluated in detail. However, streamline distributions around moist objects, and temperature and moisture isotherms inside the moist objects were visualized at distinct H/D distances and Re numbers for θ = 0°, 45°, and 90°. Velocity and temperature contour distributions were displayed for all θ angles and H/D distances for the Re number of 500. The consequences of this work were matched with the computational and empirical consequences of the studies conducted in the literature, and it was noticed that the outcomes were in good agreement with each other. For Re = 500 and H/D = 3.33, an increase in the θ from 0° to 30° resulted in a 17.98 % increase in the Nua. Furthermore, the lowest moisture rates were reached at θ = 45° − H/D = 3.33, while the highest rates were observed at θ = 0° − H/D = 5.