Numerical Simulation And Visual Research On The Physical Properties Changes Of Potato During Hot Air Drying Process

Dry products of potatoes become more and more popular because they have good nutrition, and small volume, light weight, easy for transportation and convenient for carrying and storage. Due to the characteristics such as little equipment investment, simple operation, easy to control, hot-air drying is widely applied in potato dry process But in the process of hot-air drying, the potatoes will have some physical changes as shrinkage, weather-shack, surface hardening, porosity, in some extent, it will reduce the physical quality of dried potatoes, which can not meet people's needs. So in order to improve the physical quality of dried potatoes, we conduct the research on the hot-air seasoning process and master the characteristics of the hot-air seasoning of potatoes. However, the traditional experiment are both material-consuming and time-consuming and it also can not forecast and monitor the process of drying, so there comes the numerical simulation which can forecast the rules of the food hot-air seasoning quickly, directly and precisely, following the visual research methods.This study takes the potatoes as the experimental material, with the temperature; the moisture content and the contraction of potatoes in the seasoning process as aims, and makes the research on the potato's internal heat transfer, mass transfer, process of shrinking in the potato seasoning process. The three-dimensional unsteady state heat conduction and moisture equation and the diffusion equation and stress-strain relationship equation are deduced by Galerkin's finite element method and programmed by Fortran language. The internal heat transfer, mass transfer during the potato drying process was simulated. The simulation results are verified by the experimental data, then transferred to Femap software to realize the visualization of potato's temperature, moisture and volume and direction of contraction in the seasoning process. the following conclusions can be drawn:1. a model was established for heat and mass transfer and shrinkage during the process of potato hot air drying,and this model simulated the changes of the potato temperature, moisture and shrinkage rate of the volume and direction during the drying process.2. The calculated values was agreed with the experimental values to prove that the subject of the model is reliable.3. Femap software used in this study to achieve the potato physical changes of visualization in the process of hot air drying.4. The study did not take into account the deformation of the factors in the contraction of the potato research, we will make up this shortfall in the future work.Through the numerical simulation and visual research on the physical properties changes of potato during hot air drying process, we can not only directly and precisely master the process and rules of the food hot-air seasoning, but also optimize the hot-air drying technology according to the forecast results.