Study on Drying Characteristics and Numerical Model of Turnips Based on Infrared Radiation Drying Technology

ABSTRACT To overcome the issues of low efficiency and poor quality associated with traditional hot‐air drying in turnip processing, this study employed infrared radiation drying technology to systematically investigate the effects of different temperatures (50°C, 55°C, 60°C, and 65°C) and slice thicknesses (4, 6, and 8 mm) on the drying characteristics and quality of Xinjiang turnips. Results indicate that the drying process primarily consists of a rate‐decreasing stage, with drying time shortening as temperature increases and thickness decreases. The effective moisture diffusion coefficient ( D eff ) ranged from 2.14 × 10 −10 to 1.14 × 10 −9 m 2 /s, increasing with both temperature and thickness. Activation energies for different thicknesses (4, 6, and 8 mm) were 40.90, 33.91, and 28.59 kJ/mol, respectively. Among various drying mathematical models, the Page model demonstrated the best fitting performance ( R 2 > 0.99). Regarding turnip quality, increased temperature led to higher color difference ∆ E and higher rehydration ratio, whereas increased thickness reduced both parameters. A two‐dimensional axisymmetric heat and mass transfer model constructed using COMSOL yielded simulated values for dry‐basis moisture content and temperature with experimental values, achieving determination coefficients R 2 of 0.976 and 0.952, respectively. This study provides theoretical support for optimizing turnip drying using infrared technology and advancing numerical simulation techniques.