中国物理B ›› 2018, Vol. 27 ›› Issue (8): 80504-080504.doi: 10.1088/1674-1056/27/8/080504

• GENERAL • 上一篇    下一篇

Transport of velocity alignment particles in random obstacles

Wei-jing Zhu(朱薇静), Xiao-qun Huang(黄小群), Bao-quan Ai(艾保全)   

  1. 1 Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, China;
    2 Basic Teaching Department, Neusoft Institute Guangdong, Foshan 528000, China
  • 收稿日期:2018-04-20 修回日期:2018-06-04 出版日期:2018-08-05 发布日期:2018-08-05
  • 通讯作者: Bao-quan Ai E-mail:aibq@scnu.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11575064 and 11175067), the PCSIRT (Grant No. IRT1243), the GDUPS (2016), and the Natural Science Foundation of Guangdong Province, China (Grant No. 2014A030313426).

Transport of velocity alignment particles in random obstacles

Wei-jing Zhu(朱薇静)1, Xiao-qun Huang(黄小群)2, Bao-quan Ai(艾保全)1   

  1. 1 Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, China;
    2 Basic Teaching Department, Neusoft Institute Guangdong, Foshan 528000, China
  • Received:2018-04-20 Revised:2018-06-04 Online:2018-08-05 Published:2018-08-05
  • Contact: Bao-quan Ai E-mail:aibq@scnu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11575064 and 11175067), the PCSIRT (Grant No. IRT1243), the GDUPS (2016), and the Natural Science Foundation of Guangdong Province, China (Grant No. 2014A030313426).

摘要: We numerically investigate the trapping behaviors of aligning particles in two-dimensional (2D) random obstacles system. Under the circumstances of the effective diffusion rate and the average velocity tend to zero, particles are in trapped state. In this paper, we examine how the system parameters affect the trapping behaviors. At the large self-propelled speed, the ability of nematic particles escape from trapping state is enhancing rapidly, in the meanwhile the polar and free particles are still in trapped state. For the small rotation diffusion coefficient, the polar particles circle around (like vortices) the obstacles and here particles are in trapped state. Interestingly, only the partial nematic particles are trapped in the confined direction and additional particles remain flowing. In the free case, the disorder particle-particle collisions impede the motion in each other's directions, leading the free particles to be trapped. At the large rotation diffusion coefficient, the ordered motion of aligning particles disappear, particles fill the sample evenly and are self-trapped around obstacles. As the particles approach the trapping density due to the crowding effect the particles become so dense that they impede each other's motion. With the increasing number of obstacles, the trajectories of particles are blocked by obstacles, which obstruct the movement of particles. It is worth noting that when the number of the obstacles are large enough, once the particles are trapped, the system is permanently absorbed into a trapped state.

关键词: Brownian motion, self-propelled particles, stochastic processes

Abstract: We numerically investigate the trapping behaviors of aligning particles in two-dimensional (2D) random obstacles system. Under the circumstances of the effective diffusion rate and the average velocity tend to zero, particles are in trapped state. In this paper, we examine how the system parameters affect the trapping behaviors. At the large self-propelled speed, the ability of nematic particles escape from trapping state is enhancing rapidly, in the meanwhile the polar and free particles are still in trapped state. For the small rotation diffusion coefficient, the polar particles circle around (like vortices) the obstacles and here particles are in trapped state. Interestingly, only the partial nematic particles are trapped in the confined direction and additional particles remain flowing. In the free case, the disorder particle-particle collisions impede the motion in each other's directions, leading the free particles to be trapped. At the large rotation diffusion coefficient, the ordered motion of aligning particles disappear, particles fill the sample evenly and are self-trapped around obstacles. As the particles approach the trapping density due to the crowding effect the particles become so dense that they impede each other's motion. With the increasing number of obstacles, the trajectories of particles are blocked by obstacles, which obstruct the movement of particles. It is worth noting that when the number of the obstacles are large enough, once the particles are trapped, the system is permanently absorbed into a trapped state.

Key words: Brownian motion, self-propelled particles, stochastic processes

中图分类号:  (Fluctuation phenomena, random processes, noise, and Brownian motion)

  • 05.40.-a
45.50.-j (Dynamics and kinematics of a particle and a system of particles) 02.50.-r (Probability theory, stochastic processes, and statistics)