تقرير
Hopper flows of deformable particles
| العنوان: | Hopper flows of deformable particles |
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| المؤلفون: | Cheng, Y., Treado, J. D., Lonial, B., Habdas, P., Weeks, E. R., Shattuck, M. D., O'Hern, C. S. |
| المصدر: | Soft Matter 18 (2022) 8071 |
| سنة النشر: | 2022 |
| المجموعة: | Condensed Matter |
| مصطلحات موضوعية: | Condensed Matter - Soft Condensed Matter |
| الوصف: | Numerous experimental and computational studies show that continuous hopper flows of granular materials obey the Beverloo equation that relates the volume flow rate $Q$ and the orifice width $w$: $Q \sim (w/\sigma_{\rm avg}-k)^{\beta}$, where $\sigma_{\rm avg}$ is the average particle diameter, $k\sigma_{\rm avg}$ is an offset where $Q\sim 0$, the power-law scaling exponent $\beta=d-1/2$, and $d$ is the spatial dimension. Recent studies of hopper flows of deformable particles in different background fluids suggest that the particle stiffness and dissipation mechanism can also strongly affect the power-law scaling exponent $\beta$. We carry out computational studies of hopper flows of deformable particles with both kinetic friction and background fluid dissipation in two and three dimensions. We show that the exponent $\beta$ varies continuously with the ratio of the viscous drag to the kinetic friction coefficient, $\lambda=\zeta/\mu$. $\beta = d-1/2$ in the $\lambda \rightarrow 0$ limit and $d-3/2$ in the $\lambda \rightarrow \infty$ limit, with a midpoint $\lambda_c$ that depends on the hopper opening angle $\theta_w$. We also characterize the spatial structure of the flows and associate changes in spatial structure of the hopper flows to changes in the exponent $\beta$. The offset $k$ increases with particle stiffness until $k \sim k_{\rm max}$ in the hard-particle limit, where $k_{\rm max} \sim 3.5$ is larger for $\lambda \rightarrow \infty$ compared to that for $\lambda \rightarrow 0$. Finally, we show that the simulations of hopper flows of deformable particles in the $\lambda \rightarrow \infty$ limit recapitulate the experimental results for quasi-2D hopper flows of oil droplets in water. Comment: 15 pages, 12 figures |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1039/D2SM01079H |
| URL الوصول: | http://arxiv.org/abs/2208.05581 |
| رقم الأكسشن: | edsarx.2208.05581 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1039/D2SM01079H |
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