School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom.
Phys Rev Lett. 2013 Jul 19;111(3):038001. doi: 10.1103/PhysRevLett.111.038001. Epub 2013 Jul 16.
Using a vertically vibrated, fully three-dimensional granular system, we investigate the impact of dissipative interactions between the particles in the system and the vertical sidewalls bounding it. We find that sidewall dissipation influences various properties of the bed including, but not limited to, the spatial distribution of granular temperatures, the functional form of velocity distributions, and the strength of convection. Simple, monotonic relationships are observed for all the aforementioned properties, including a striking linear relationship between convection strength and wall dissipation. We conclude that sidewall effects are not limited to the vicinity of the walls themselves, but extend into the bulk of the system and hence must be considered even in relatively wide, three-dimensional systems. We also propose the possibility of using the alteration of sidewall material as a method of "tuning" certain system parameters in situations where changing the bulk properties or driving parameters of a granular system may be undesirable.
我们利用一个垂直振动的、完全的三维颗粒系统，研究了系统内颗粒之间的耗散相互作用以及垂直边界对其的影响。我们发现，壁面耗散会影响床层的各种特性，包括但不限于颗粒温度的空间分布、速度分布的函数形式以及对流的强度。所有上述特性都观察到了简单的单调关系，包括对流强度和壁面耗散之间引人注目的线性关系。我们得出的结论是，壁面效应不仅局限于壁面附近，而是延伸到系统的主体部分，因此即使在相对较宽的三维系统中也必须考虑壁面效应。我们还提出了一种可能性，即通过改变壁面材料来“调整”某些系统参数，这种方法在改变颗粒系统的体性质或驱动参数可能不可取的情况下是有用的。
