生物对流流场的数值分析

Numerical investigation of bioconvectionflow field

在微生物培养中,由于微生物的趋向性运动造成了流体的非稳定密度分布,由此引发的宏观对流称为生物对流。本文采用数值解析方法,对二维空间内负趋地性生物对流流场进行了模拟计算,考察了细胞密度和运动能力对流动形态的影响。结果表明:培养基内流体因微生物的趋向性运动引起的宏观流动,在中心处会逐步趋于稳定;微生物细胞密度和运动能力都可以促进对流;细胞密度增大可以抑止细胞向上运动,而运动能力的增强则加强向上的流动。

The convection phenomena in suspensions of swimming micro-organisms is called bioconvection. Numerical simulations of gravitaxis micro-organisms＇ bioconvection plumes in 2D space are carried out, and the influence of some parameters is studied. The results show that convection caused by gravitaxis movement of micro-organisms reaches a steady state in the center of container. Both the density and swimming speed of cells can boost the convection. Increasing of swimming speed enhances the upward movement while density effects in the opposite way.