“MORE HASTE, LESS SPEED” CLOGGING PHENOMENON OF ACTIVE PARTICLES PASSING THROUGH A BOTTLENECK DRIVEN BY EXTERNAL VELOCITY FIELD

When the particle's velocity or squeezing among particles is increased, the flow rate of discrete particles passing through the bottleneck is significantly reduced, which is called the “more haste, less speed” effect. In this paper, molecular dynamics simulation is used to study the effects of self-propelled force on the bottleneck clogging of active particles driven by different external velocity fields. With the increase of self-propelled force, the flow rate of active particles decreases. Based on the power-law exponent of complementary cumulative distribution function and clogging probability, it is explained that although the self-propelled force can effectively enhance the particle motility, it also causes the increase of the clogging probability, consequently leading to the decrease of the flow rate. On the pedagogical side, as a typical complex system, bottleneck flow of active particle can assist students in understanding the physical thought that optimal individual does not necessarily bring global optimum. Besides, it is beneficial to the development of academic ability and scientific literacy for undergraduates, by the rigorous training of data processing and statistical analysis.