多根螺旋体鞭毛在二维微小周质空间内的受力特性

目的研究多根螺旋体鞭毛成带状分布情况下在微小周质空间内的受力特性。方法使用两平行平板的二维模型简化周质空间,采用数值模拟方法,研究鞭毛间距和偏心率对螺旋体鞭毛受力和力矩以及对螺旋体原生质柱切应力的影响规律。结果 (1)鞭毛水平方向受力曲线随偏心率呈抛物线变化规律,鞭毛两侧压力差和黏性阻力随偏心率逐渐增大是造成鞭毛水平方向受力曲线出现峰值的主要原因,鞭毛间距对鞭毛水平方向受力影响较小;(2)鞭毛力矩曲线随偏心率呈指数变化规律,鞭毛间距越小,鞭毛力矩越大;(3)鞭毛间距对原生质柱壁面切应力没有显著影响,但随鞭毛数量增多和偏心率增大而增大。结论数值模拟结果可以定性反映螺旋体鞭毛受力特性,为进一步认识螺旋体形态结构、运动机制以及治病特性提供参考。

Mechanical characteristics of the spirochete flagella in 2D micro-periplasmic space

Objective To investigate mechanical characteristics of the spirochete flagella with tight-fitting ribbon configuration in micro-periplasmic space. Methods The 2D model of two parallel plates was used to simplify the periplasmic space, and the effects of flagellum spacing and eccentricity on force and torque acted on the spirochete flagella, and wall shear stress acted on the spirochete protoplasmic cylinder were studied by using numerical simulation method. Results (1) The relationship between the flagellum horizontal force and eccentricity was presented as a parabolic curve, and the peak value of the flagellum horizontal force was mainly caused by the gradual increase of pressure difference at two sides of the cylinder and the resistance viscous force as well. Flagellum spacing had no significant influence on flagellum horizontal force. (2) The relationship between the flagellum torque and eccentricity was presented as an exponential curve, and smaller flagella spacing would cause bigger flagella torque. (3) Flagellum spacing had no significant effect on wall shear stress of the protoplasmic cylinder, but it would be increased with the number of flagella and the eccentricity increasing. Conclusions Numerical simulation results in this study can qualitatively reflect mechanical characteristics of the spirochete flagella, and also provide references for further understanding the morphology of spirochete as well as its kinematic mechanism and pathogenic characteristics.