科研之友
微信
新浪微博
Facebook
分享链接
摘要
Based on the fact that frost structure is fractal, the fractal model of water vapor diffusion in frost was established and the effective diffusivity of water vapor in frost was deduced. In this model, many parameters were used to describe frost structure, such as pore fractal dimension, channel axes fractal dimension, porosity, maximum and minimum pore dimension, and minimum distance of channel. The results show that this model embodies properly channel curve's change and its effects on water vapor diffusion. Effective diffusivity increases slowly with the increase of porosity at lower porosity, because the pore is small and the channel is highly curved. However, effective diffusivity increases rapidly at higher porosity, because the increase of porosity may unite little pores, which makes the degree of the channel curving decline.
