标题： 微重力中的颗粒阻塞和流变学 显示英文标题

标题： Granular jamming and rheology in microgravity

摘要： 了解颗粒材料在低重力环境下的行为对于行星科学和太空探索至关重要。 它还可以帮助我们理解通常被重力掩盖的颗粒现象。 在地球上，重力主导颗粒行为，但将它的作用与固有的粒子相互作用区分开来是具有挑战性的。 我们展示了一系列在微重力环境下进行的压缩和剪切实验，使用了应用空间技术与微重力中心（ZARM）落塔和不莱梅重力塔（GTB）。 我们自主研发的实验装置通过泰勒-库埃特流变仪实现了对填充密度和原位剪切应力的精确测量。 我们发现，在微重力环境下，颗粒的堵塞转变发生在较低的填充密度下，这证实了重力促进了致密化。 流变测量进一步表明，在微重力环境下，缺乏次级力场且颗粒间黏附力占主导地位，增加了颗粒介质流动所需的应力。 这些发现突显了重力在增强致密化和流动方面的双重作用，并展示了在低重力和微重力环境中适用的定制颗粒模型的必要性。 显示英文摘要

摘要： Understanding how granular materials behave in low gravity is crucial for planetary science and space exploration. It can also help us understand granular phenomena usually hidden by gravity. On Earth, gravity dominates granular behavior, but disentangling its role from intrinsic particle interactions is challenging. We present a series of compression and shear experiments conducted in microgravity using the Center of Applied Space Technology and Microgravity (ZARM) drop tower and GraviTower Bremen (GTB). Our in-house developed experimental setup enables precise measurement of packing density and in-situ shear stress via a Taylor-Couette rheometer. We find that the jamming transition occurs at lower packing density in microgravity than on Earth, confirming that gravity promotes densification. Rheological measurements further reveal that in microgravity, the lack of a secondary force field and predominance of cohesive interparticle forces increase the stress needed for granular media to flow. These findings highlight gravity's dual role in enhancing both compaction and flow, and demonstrate the need for tailored granular models, valid in low- and microgravity environments.