We study the passage of active and passive granular particles through a bottleneck under gravitational bias. The grains are pharmaceutical capsules with spherocylindrical shapes on a vibrating table. The vibrating ground plate is slightly tilted in order to break the in-plane symmetry and to give particles a motivation to move in a preferential direction. The passage through a narrow gate with openings comparable to the grain length is studied using video imaging. Particle positions and velocities are extracted from the recorded frames. We find striking differences between the behaviour of asymmetric, active capsules and symmetric, passive ones. The active grains show an astonishingly strong dependence of the passage rates on the gate width, while for passive grains, this dependence is linear as expected. The cumulative distributions of delays between subsequent particles passing the outlet, a key parameter in egress studies, also differ substantially between active and passive grains. Tilt angle and excitation parameters have only little influence on the observed dynamic features, they merely rescale time.

我们研究了重力偏置下主动和被动颗粒通过瓶颈的通道。谷物是在振动台上呈球形的药物胶囊。振动的接地板略微倾斜，以破坏平面内的对称性，并使粒子有动力朝优先方向移动。使用视频成像研究了具有与晶粒长度相当的开口的狭窄门的通道。从记录的帧中提取粒子的位置和速度。我们发现非对称，主动胶囊与对称，被动胶囊的行为之间存在显着差异。有源晶粒对通过率的门极宽度显示出惊人的强烈依赖性，而对于无源晶粒，这种依赖关系与预期的呈线性关系。后续颗粒通过出口之间的延迟累积分布（出口研究中的关键参数）在主动和被动晶粒之间也存在很大差异。倾斜角和激励参数对观察到的动态特征影响很小，它们只是重新调整时间。