Vibration-Driven Vehicles Flowing Through Bottlenecks

PATTERSON, G.A.; SANGIULIANO JIMKA, F.; KÖNIG, P.G.; PUGNALONI, L.A.; GARCIMARTÍN, A.; ZURIGUEL, I.; FIERENS, P.I.; PARISI, D.R.

Washington

Conferencia; Traffic and Granular Flow 2017; 2017

Presentacion oral DRPThe study of self-propelled particles has received considerable attention in the last decades, both in disciplines related to statistical physics and also in the development of specific applications. These investigations study the collective behavior of microor- ganisms, flocks, herds, pedestrian dynamics and transport systems, among other self- propelled agents.In this work, we present experimental results on mechanical Vehicles Driven by Vi- brations (VDV) commercially available (Hexbug Nano). In particular, we study their collective dynamics when flowing through a narrow constriction in a hopper-like geometry over an horizontal plane. The experiments were recorded with a digital camera and the trajectory and orientation of each vehicle were obtained by image processing.We found that, for this particular geometry, the system presents a clear self-organized behavior. Two different situations are observed, depending on the size of the group that is moving collectively towards the exit. These two situations can be quantitatively dif- ferentiated looking at a herding parameter (defined via the orientation of the vehicles), which presents a bi-modal distribution.The mean flow rate is smaller for the experiments with a larger number of vehi- cles ?pushing? at the door. Furthermore, in this case, the distribution of time intervals between the passage of two consecutive vehicles through the door shows a power law tail, with a greater probability of having long flow interruptions due to clogging. These observations are compatible with the faster-is-slower effect recently observed experi- mentally in other active matter systems [1] where ?faster? should be interpreted in a more general way as ?higher pressure? present near the exit door.References[1] J.M.Pastor,A.Garcimart ́ın,P.A.Gago,J.P.Peralta,C.Mart ́ın-Go ́mez,L.M. Ferrer, D. Maza, D. R. Parisi, L. A. Pugnaloni, I. Zuriguel. Phy. Rev. E 92, no. 6 (2015): 062817.