发表机构
University of California, Santa Barbara; University of Maryland, College Park（加州大学圣塔芭芭拉分校; 马里兰大学帕克分校）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过实验和离散元模拟，验证了圆形孔径稳态通量框架在三角形、矩形及透镜形孔径中的适用性，发现水力直径是控制排放的关键长度，并揭示了边界层膨胀机制。
AI 中文摘要
我们最近提出了一个用于圆形孔径中颗粒稳态质量通量的框架 [R.~S.~Sharma 等人，Phys. Rev. Lett. 136, 068204 (2026)]。在此，我们结合球形颗粒通过三角形和矩形孔径排放的实验和离散元模拟，以在圆形开口之外检验该框架。尽管孔径形状发生变化，我们观察到类似的自由落体通量，但相关的输运长度有所修改。由于约束引起的偏差反映了堆积结构的改变，这可以通过几何学来解释。我们证明了由孔径边缘施加的边界层膨胀是导致各种孔径形状下通量减少的机制。通过将局部堆积亏损在开口上积分，我们确定了水力直径 $D_h=4A/P$（其中 $A$ 和 $P$ 分别为孔径面积和周长）作为主要的约束长度。该长度还为平均出口速度提供了一个参考尺度 $\sqrt{gD_h}$，当孔径远大于单个颗粒时适用。相同的局部堆积模型无需进一步拟合即可预测透镜形孔径中的场，而归一化排放速率在测试的形状中遵循共同趋势。
英文摘要
We recently proposed a framework for the steady mass flux of particles through circular apertures [R.~S.~Sharma \textit{et al.}, Phys. Rev. Lett. \textbf{136}, 068204 (2026)]. Here, we combine experiments and discrete-element simulations of spherical particles discharging through triangular and rectangular apertures to test this framework beyond circular openings. Despite changes in aperture shape, we observe a similar free-fall flux, with a modified relevant transport length. Deviations due to confinement reflect packing modifications, which are explained by geometry. A boundary layer dilation imposed by the aperture edge is shown to be a mechanism for the decrease of flux across various aperture shapes. By integrating the local packing deficit over the opening, we identify a hydraulic diameter $D_h=4A/P$, where $A$ and $P$ are the aperture area and perimeter, respectively, as the leading confinement length. This length also provides a reference scale, $\sqrt{gD_h}$, for the mean outlet velocity when the aperture is much larger than an individual particle. The same local packing model predicts the field in a lens-shaped aperture without further fitting, while the normalized discharge rates follow a common trend across the tested shapes.
CommentsMain: 10 pages, 7 figures. Supplementary materials: 3 pages, 2 figures
