基于N-S方程的泡沫陶瓷渗流微观数值模拟

Numerical simulation of microcosmic flow in foam ceramics based on N-S equation

用喉道和孔隙体构造孔径均匀，高度有序的泡沫陶瓷微观结构，孔隙之间的连通性用配位数描述。用N-S方程描述孔隙中的流体运动，建立数学模型，将流体力学理论引入到渗流力学中，通过对两种具有不同配位数的泡沫陶瓷渗流过程进行微观数值模拟，获得陶瓷微孔道中的流速场和压力场分布状况。计算结果表明，由于孔隙结构对渗流过程的影响，在相同压差的条件下，配位数为3的Ⅰ型泡沫陶瓷渗透流量比配位数为4的Ⅱ型泡沫陶瓷渗透流量高21．29％，Ⅰ型泡沫陶瓷渗透性能明显优于Ⅱ型泡沫陶瓷。孔隙拓扑结构是影响泡沫陶瓷宏观渗透性能的重要因素，具有相同宏观统计参数（如孔隙率）的泡沫陶瓷，也会由于孔隙的分布方式不同而在性能上存在差异。研究结果对于多孔陶瓷制备与性能研究具有重要意义。

The microcosmic structure of foam ceramics which was high ordered was constructed by pore throats and pore bodies, and its connectivity was described by coordination number. Using N-S equation as the governing equation of fluid flowing in micro-pores, we set up mathematic model. Velocity field and press field in micro-pores were obtained by numerical simulations of seepage processes in two kinds of foam ceramics which had different coordination numbers. Simulation results showed that as the impact of pore structure to seepage process, in the same differential press condition, the flux of foam ceramics Ⅰ which had coordination number 3 was higher than the flux of foam ceramics Ⅱ which had coordination number 4 by 21.29%. Filtering capability of foam ceramics Ⅰ was obviously better. Pore structure is an important factor to impact the macroscopically filtering performance of foam ceramics; Foam ceramics which have the same macroscopically statistical parameter such as porosity but different pore distribution fashion will have different performance. Conclusions are useful for preparation and performance study of foam ceramics.