Coupling drying of wet and heat field of corn pile based on porous medium model

Abstract Corn that are not properly dried can result in a lot of waste. Therefore, in this study, the corn pile was used as porous medium for hot air drying, and the coupling method of multiple physical fields was used to simulate and analyze the corn air‐drying silo with different initial conditions and different sizes. The results show that increasing the temperature of hot air could increase the temperature gradient inside corns and promote the evaporation of water. The higher the wind speed, the better the convective heat transfer effect between corn and air, thus improving the drying efficiency. The smaller the ratio of height to diameter of air‐drying silo, the more corn dried in the direction of hot air flow, resulting in poor drying effect. Increasing the inner diameter of the air‐drying silo will reduce the heat transfer efficiency. The lower the bed of the air‐drying silo, the closer the corns are to the hot air inlet, the faster the heating rate and the better the drying effect. The model has good performance and can be used as a mathematical tool to predict the change of maize wet heat field. Practical applications In order to solve the integral problem of corn drying, the model uses corn grain pile as porous medium for hot air drying. The model investigated the changes of temperature field and humidity field during the drying process of grain pile in corn air‐drying silo. In addition, the characteristics of the model introduced in this study may qualify it for automatic control of corn air‐drying silo and online prediction of drying times to achieve the desired drying effect.