摘要
研究稻谷颗粒内部水分的迁移规律,以求达到较好的烘干效果,是一个重要的问题。该文研制了可用于空间轴对称湿扩散问题的有限元计算软件,并用其对描述圆粒、长粒稻谷的3层圆球和椭球两种模型进行计算,得到了两种模型在干燥、缓苏状态下的湿度及其梯度场随时间变化规律。经分析发现,烘干温度较低时,椭球脱湿速度低于圆球,烘干温度较高时,两者差异变小。两模型的含水率(干基)及其梯度分布有明显差别。
The universal
software of finite element method was developed for solving water diffusion equations of
axisymmetrical body. Using the program, a series of numerical solutions were obtained for the
3layer sphere models and 3layer ellipsoid models, which were used to describe short and
long grain rice respectively. Those results show that the difference of kernels desorption rates
between the two models become small when drying temperature is high. The distribution of
moisture and its gradients in both models during drying was given for different drying
procedures. It was suggested that the boundary condition is better modified to incorporate the
phenomenon that surface moisture is changing gradually. Moisture gradient in the kernel varies
during drying, and the changing of the gradients may cause damage to the kernels.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
1999年第2期189-193,共5页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金
关键词
稻谷
湿度
有限元法
干燥
水分迁移
烘干
rough rice,moisture,finite element method,diffusion,drying